Electrotechnologies for Waste and Water Treatment

8"8Rp53 1.7 Topics: y43 EPRl EM-5418 Waste processing F Project 2416-25 EPRl Water treatment Final Report Electric Power Resource recovery October 1987 Research Institute Industrial wastes Electrotechnology End use

Electrotechnologies for Waste and Water Treatment

Prepared by Science Applications International Corporation Los Altos, California

REPORT SUMMARY

~ S U BJ ECTS Industrial electric technologies / Land and water quality / Hazardous and toxic waste management

TOPICS Waste processing Industrial wastes Water treatment Electrotechnology Resource recovery End use

AUDIENCE R&D engineers / Marketing managers

Electrotechnologiesfor Waste and Water meatment Recent environmental regulations have created a potential new market for electrotechnologies-treatment of industrial and municipal waste and water. This report describes a wide range of such processes and applications.

BACKG R 0U N D Stricter environmental protection regulations and the decrease of available space for waste disposal have motivated an ongoing reevaluation of waste management technologies and an emerging interest in innovative waste ~ processing methods.

~ OBJECTIVES To identify and examine waste and water treatment technologies, particularly electricity-intensive processes. To identify specific areas where R&D could have a significant impact on the near- to intermediate-term implementation of electrotechnologies for waste and/or water treatment.

APPROACH The investigators gathered information on waste and water treatment technologies and processes through extensive library searches and from their own company files. They solicited similar information, including technology growth projections, from industrial sources. To compile a summary of past and present research in waste management, they examined databases containing EPRl reports and government documents. Discussions with government agency experts confirmed industrial sources of hazardous and non- hazardous wastes and clarified relevant regulations. Where data were available, the research team calculated the energy use of specific treatment processes. They then evaluated the processes, comparing costs of electro-

technologies with present methods. ~~

RESULTS Three areas have high potential for the introduction of electrotechnologies: hazardous-waste treatment, wastewater treatment, and resource recovery. _1 -- e Among many processes under research for hazardous-waste management are pyrolysis (including plasmas and infrared heaters), electrochemical concentration (including electrodialysis), freeze concentration, and supercritical fluid oxidation.

EPRl EM-5418s Electricity-intensive processes for water treatment include ion exchange, reverse osmosis, and ultrafiltration. Some applications of these processes are in early stages of development. For waste recycling, plasma, reverse osmosis, and electrodialysis can be employed in metals recovery and for melting both glass and metal.

EPRl PERSPECTIVE Greater use of electricity for waste treatment could result in a substan-

~ tial increase in utility electrical loads, with the large quantities of waste generated annually. Relatively low energy costs presently-and for the foreseeable future-limit the use of electrotechnologies for treating mu- ~~ nicipal solid wastes and nonhazardous industrial wastes. However, escalating costs of present disposal methods indicate that the potential for using electrotechnologies is much greater for hazardous wastes. In addition, recent regulations have created potential applications for electrotechnologies in wastewater treatment and resource recovery.

PROJECT RP2416-25 EPRl Project Managers: Alan Karp; I. Leslie Harry Energy Management and Utilization Division Contractor: Science Applications International Corporation

For further information on EPRl research programs, call EPRl Technical Information Specialists (415) 855-2411. Electrotechnologies for Waste and Water Treatment

EM-5418 Research Project 2416-25

Final Report, October 1987

Prepared by

SCIENCE APPLICATIONS INTERNATIONAL CORPORATION 5150 El Camino Real, Suite C-31 Los Altos, California 94022

Principal Investigators F! Estey H. Hampton S. Sefidpour

Prepared for

Electric Power Research Institute _I

3412 Hillview Avenue r-- Palo Alto, California 94304

EPRl Project Managers A. D. Karp I. L. Harry Industrial Program Energy Management and Utilization Division ORDERING INFORMATION Requests for copies of this report should be directed to Research Reports Center (RRC), Box 50490, Palo Alto, CA 94303, (415) 965-4081. There is no charge for reports requested by EPRl member utilities and affiliates, US. utility associations, US. government agencies (federal, state, and local), media, and foreign organizations with which EPRl has an information exchange agreement. On request, RRC will send a catalog of EPRl reports.

Electric Power Research Institute and EPRl are registered service marks of Electric Power Research Institute, Inc.

NOTICE This report was prepared by the organization(s) named below as an account of work sponsored by the Electric Power Research Institute, Inc. (EPRI). Neither EPRI, members of EPRI, the organization(s) named below, nor any person acting on behalf of any of them: (a) makes any warranty, express or implied, with respect to the use of any information, apparatus, method, or process disclosed in this report or that such use may not infringe privately owned rights: or (b) assumes any liabilities with respect to the use of, or for damages resulting from the use of, any information, apparatus, method, or process disclosed in this report. Prepared by Science Applications International Corporation Los Altos, California ABSTRACT

This work identifies and examines the use of electrotechnologies in the treatment of solid and liquid wastes. The types of wastes studied were divided into five major classifications: 1) municipal solid wastes, 2) municipal wastewater, 3) non- hazardous industrial wastes, 4) hazardous industrial wastes and 5) nuclear wastes. Within each category, information was gathered on the quantities of waste generated, types of wastes generated, current disposal or treatment technologies, research on promising treatment technol ogies, and energy usage for current and promi sing technologies. Information in the above areas was also put together for the topics of drinking water and resource recovery.

Current research and development programs were identified within the Environmental Protection Agency (EPA), the Electric Power Research Institute (EPRI), and private industry. In addition, current regulations were reviewed to determine effects on waste management technol ogies.

iii

ACKNOWLEDGMENTS

The project team at Science Applications International Corporation is grateful for the assistance and guidance provided by Mr. Alan Karp and Mr. Les Harry of the Electric Power Research Institute (EPRI) who supported this project from its in- ception. Mr. Steve Parker of EPRI also provided valuable help in gathering an enormous number of references on waste generation and treatment technologies. At SAIC, Mr. Mark Evans must be gratefully acknowedged for providing useful assistance and advice.

CONTENTS

Section Page

1 SUMMARY 1-1 Study Approach 1-1 Summary of Research Opportunities 1-4 Hazardous Waste Treatment 1-4 Treatment of Wastewater 1-6 Re so u rce Rec ov ery 1-6 Concl usi on 1-7

2 MUNICIPAL WASTES 2-1 Municipal Sol id Wastes 2-1 Characterization and Quantities of MSW 2-1 Management and Disposition of Munci pal Sol id Waste 2-1 R e so u rce R ec ov e ry 2-5 Refuse-to-Energy systems 2-7 Munici pal Wastewater 2-11 Management Technol ogies for POTWs 2-12 Activated S1 udge 2-17 Condi tioni ng/Dewatering 2-17 Thermal Conditioning 2-42 Incineration 2-42 Anaerobic Digestion 2-48 S1 udge Stabilization A1 ternat v es 2-51 Advanced Wastewater Treatment Processes 2-51 Methods of Disposal for Munic pal Sludges 2-55 References 2-57

3 NON-HAZARDOUS INDUSTRIAL WASTES 3-1 Management Technol ogies for Non-Hazardous Industrial Wastes 3-1 Industria1 Wastewater Treatment 3-18 Agr cultural Wastes 3-18 Management Technol ogies 3-18 Min ng Wastes 3-18

vii Section Page

3 Types of Waste 3-26 Management Technol ogi es 3-26 References 3-28

4 Hazardous Industrial Wastes 4-1 Characterization and Quantities of Hazardous Wastes 4-1 - Waste Management Practices 4-6 Hazardous Waste Treatment Tec hn olog ies 4-9 Air Flotation 4-13 Biological Treatment 4-16 Electrodialysis 4-21 Electrolysis 4-26 Electrophoresi s 4-33 Filtration Technologies 4-37 Freeze Crystallization 4-38 High Energy Electron Treatment 4-41 High Temperature F1 uid Wall Reactor 4-44 Incineration 4-50 Infrared Furnace 4-60 Ion Exchange 4-64 Microwave Discharge 4-66 Mol ten Glass Incinerator 4-66 P1 asma-Arc Heaters 4-69 Pyrolytic Incineration Rotary Hearth and In-drum 4-73 Ozonat ion 4-78 Reverse Osmosi s 4-83 Sol idif icati on/Stabi 1 izati on 4-87 Supercritical F1 uid Oxidation 4-98 U1 trafi 1 trati on and Microfi 1tration 4-100 U1 t raviol et Radi ation 4-111 Wet Air Oxidation 4-115 References 4-121

5 NUCLEAR WASTES 5-1 Management of Nuclear Wastes in the U.S. 5-3 Processing Technol ogi es 5-3 High-Level Waste Treatment Vitrification 5-6

viii Section Page

5 Low-Level Waste: Volume Reduction Systems 5-9 U1 t rafi 1 t ration 5-10 S u mm a ry 5-11 References 5-12

6 RESOURCE RECOVERY 6-1 Background 6-1 Waste Reduction 6-1 Cryogenic Recovery Processing 6-9 Auto and Scrap Tire Processing 6-12 Recycling & Recovery Processing of Electric Arc Furnace Dust 6-21 Waelz Kiln 6-23 HTR Kiln 6-24 SKF P1 asmadust 6-24 On-Site Processing of EAF Dust 6-25 Recovery Processing 6-25 P1 asma-Arc Reactors 6-26 Selective Reduction Process 6-26 High-Temperature F1 uid-Wall Reactor 6-26 Recovery of Metals From Waste S1 udges 6-27 Flotation 6-27 Recycling of Cans and Bottles 6-28 References 6-31

7 DRINKING WATER 7-1 Bac kground 7-1 Chl orine 7-2 Ozone 7-3 Chlorine Dioxide 7-7 Chl orami nes 7-9 Summary 7-9 References 7-10

ix Section Page

8 INSTITUTIONAL ISSUES 8-1 -.. Hazardous Waste Legis1 ation 8-1 Non-Hazardous Waste Regul ations 8-6 References 8-10

9 CURRENT WASTE TECHNOLOGIES RESEARCH 9-1 EPRI Waste-Re1 ated Research 9-1 Waste Man agemen t 9-2 American Chemical Society 9 -5 Environmental Protection Agency 9-7 Hazardous Waste Treatment Program 9-7 Thermal Destruction Research Program 9-10 References 9-13

10 BIBLIOGRAPHY 10-1

X ILLUSTRATIONS

Figure -Page 1-1 Flows of Water and Wastes 1-2

2-1 Solid Waste Handling Flow Chart 2-3

2-2 Schematic of Mass Burning System for Power Generation 2-8

2-3 Schematic of a RDF Burning System for Power Generation 2-10

2-4 Generation, Treatment, and Disposal of Municipal Wastewater/Sludge 2-13

2-5 Schematic Diagram of an Activated Sludge System 2-18

2-6 Continuous Countercurrent Sol id Bowl Centrifuge 2-21

2-7 Belt Filter Press System 2-23

2-8 Cutaway View of a Rotary Drum Vacuum 2-26

2-9 Operating Zones of a Rotary Vacuum Filter 2-27

2-10 Plate and Frame Filter Presses 2-30

2-11 Operational Cycle for a Lasta Diaphragm Filter Press 2-31

2-12 Schematic Diagram of Roller Press Machine 2-32

2-13 Dewatered Sludge Cake Percent Solids for Mixutfes of Digested Primary 2-35 (PI) and Digested Waste Activated Sludge (WAS)

2-14 Dewatered Sludge Cake Percent Solids for Raw Primary and Raw WAS 2-36

2-15 Direct and Indirect Energy Requirements for S1 udge Dewatering 2-45 Processes

2-16 Electrical Energy Requirements for Thermal Condition (Not including 2-46 the fuel requirements)

2-17 Relative Prevalence of Sludge Combustion Facilities Operating in the 2-49 U.S.

2-18 Schematic Diagram of Conventional Anaerobic Digestors 2-49

2-19a One-Stage Suspended Growth Nitri fication 2-53

2-19b Two-Stage Suspended Growth Nitrification 2-53

2-20 Specific Energy Requirements for Suspended Growth Nitrification 2-54 (One-Stage)

xi Figure Page _I_

3-1 Industrial Water Intake in the U.S. According to Industrial Product 3-19

4-1 A Typical Air Flotation System Used in the Mineral Industry 4-14

4-2 IWS Recycle Pressurization System 4-15

4-3 A Conventional Plug-Flow Activated S1 udge System 4-19

4-4 An Activated S1 udge Treatment System 4-22

4-5 The Basic Process of Electrodialysis 4-24

4-6 Conventional Wastewater Treatment System for Electroplating 4-28

4-7 Electrolytic Recovery System 4-31

4-8 Process Flow Diagram - Andco Heavy Metal Removal Process 4-32

4-9 Recovery with a Drag-out Tank 4-34

4-10 Basic Electrophoretic Reactor 4-36

4-11 Particle Size Ranges Applicable to Various Filtration Processes 4-39

4-12 Freeze Process Steps 4-40

4-13 S ec o nda ry Re f r ig eran t P rocesS 4-42

4-14 CBI Indirect Freeze Blowdown Concentration System 4-43

4-15 AER Operations 4-45

4-16 Vertical Cross-Section of Advanced Electric Reactor 4-46

4-17 Process Configuration for the Trial Burn 4-47

4-18 Flow Sheet of a Typical Incineration Plant for Hazardous Wastes 4-54

4-19 Typical Waste Disposal System with an Infrared Furnace 4-61

4-20 Dirt Purifier & Hazardous Waste Incinerator 4-68

4-21 A Conceptual P1 asrna Processing System 4-70

4-22 P1 asmadust Process F1 ow Sheet 4-72

4-23 Two-step Pyrol itic Incineration Process 4-74

xii Figure Page

4-24 Pyrot herm System 4-15

4-25 Pyrobatch System 4-76

4-26 Corona Discharge Ozone Generator 4-81

4-27 Simplified Reverse Osmosis Flow Diagram 4-86

4-28 Artificial Ground Freezing by Brine and Liquid Nitrogen 4-94

4-29 Cost of Artificial Ground Freezing 4-99

4-30 Tubular Ultrafiltration Membrane 4-101

4-31 Spiral-Wound and Hollow-Fiber Ultrafiltration Membranes 4-102

4-32 Ultrafiltration System Typical Flow Schematic 4-104

4-33 Modified Feed and B1 eed Semi-Continuous Batch Treatment 4-106

4-34 The Wet Air Oxidation (WAO) Process 4-116

4-35 High Pressure Wet Air Oxidation Installed Unit Capitol Cost vs. 4-119 Wet Air Oxidation Unit Capacity

4-36 High-pressure Wet Air Oxidation Unit Operating Cost vs. Flow Rate 4-120

5-1 Origin of High-Level Waste 5-2

5-2 Proposed Reference U.S. Nuclear Waste Management System 5-4

5-3 Reference HLW Conversion System 5-5

5-4 Schematic of Spray Calciner/In-Can Me1 teF-V?;ocess 5-7

5-5 Schematic of Spray Calciner Ceramic Me1 ter System 5-8

6-1 Growth in Recycling (Aluminum, Copper, Glass and Lead) 6-2

6-2 Growth in Recycl ing (Paper and Steel ) 6-3

6-3 Cryogenic Grindi ng System 6-14

6 -4 Inch-Scrap Method 6-16

6-5 Prototype Cryogenic System 6-20

6 -6 Secondary Non-Ferrous Metals (A1 uminum) Process Flow Diagram 6-29

xiii Figure Page-

9-1 Thermal Destruction Research 9-12

xiv TABLES

Tab1 e -Page 1-1 Summary of Waste Generation Quantities and Disposal Methods 1-3

2-1 Composition of Municipal Solid Waste by Material Type 2-2

2-2 Disposition of Municipal Solid Waste in the U.S. 2-2

2-3 Landfill Development Costs - Past and Present 2-4

2 -4 New Typical Cost Requirements for a Land Disposal Site 2-6

2-5 Annual Energy Consumption for Wastewater Treatment 2-14

2 -6 Annual Energy Consumption for S1 udge Treatment 2-15

2 -7 Summary of Conventional Activated S1 udge Operating Conditions 2-19

2 -8 Advantages and Disadvantages of Sol id Bowl Centrifuges 2-22

2 -9 Advantages and Disadvantages of Belt Fi1 ter Presses 2-25

2-10 Advantages and Disadvantages of Vacuum Fi1 tration 2-28

2-11 Advantages and Disadvantages of Filter Presses 2-33

2-12 Typical Sol ids Capture of Dewatering Processes 2-37

2-13 Chemical Conditioners Used for Different Dewatering Processes 2-37

2-14 Typical Dosages of Chemical Conditioners for Different Dewatering 2-38 Processes

2-15 Compatibility of Dewatering Equipment with Plant Size 2-39

2-16 Dewatering Process Compatibi 1 ity with Subsequent Treatment or 2-40 U1 timate Disposal Techniques

2-17 Eva1 uation of Environmental Considerations of Dewatering Processes 2-41

2-18 General Ranges of Direct Energy Requirements for SI udge Dewatering 2-43

2-19 Indirect Energy Requirements for S1 udge Dewatering 2-44

2-20 Typical Energy Values for Several Sludge Materials and Various Fuels 2-47

2-21 Energy Requi retnents for S1 udge Stabilization 2-50

2-22 Advanced Treatment Processes 2-52

xv Tab1 e -Page 2-23 Disposal Methods for Municipal S1 udges 2-56

3-1 Listing of Industries by Estimated Annual Amounts of Non-Hazardous 3-2 Waste Generated

3-2 Sludges Generated as a Result of Pollution Control Rates for 3-4 Selected Manufacturing Industries

3-3 Summary of Industrial Non-Hazardous Waste Generation and Management 3-5

3-4 Existing Quantitative Data on Industrial Management of Non-Hazardous 3-16 Wastes

3-5 Summary of Non-Hazardous Industrial Wastewater: Its Orgin Character 3-20 and Treatment

3-6 Estimated Amounts of Waste Products in the Major Mining Industries 3-27

4-1 Data Sources for the Quantity of Hazardous Waste Generated in U.S. 4-2

4-2 A CBO Waste Classification System Based on Major Constituent and 4-3 Physical State

4-3 Estimated National Generation of Industrial Hazardous Wastes 1983, 4-4 Ranked by Waste Quantity Management Technologies

4-4 Estimated National Generation of Industrial Hazardous Wastes Ranked 4-5 by Major Industry

4-5 On- and Off-Site Waste Flows Managed by Major Industry Groups in 1983 4-7

4 -6 Estimated Hazardous Waste Disposal Quantities by Management Techno1 ogy 4-8 1983 and 1990 - Under Alternative Cases

4-7 Annual Expenditures by Major Industry Groups for Hazardous Waste 4-10 Management Under 1983 Baseline Pol icy

4-8 Range of Estimated Annual Incremental Costs to Industry of 1984 RCRA 4-11 Amendments , by 1990

4-9 Estimated Range of Annual Industrial Expenditures for Hazardous Waste 4-12 Management, 1983 and 1990, Under Alternative Cases

4-10 Electrical Energy Requirements for a Typical Ore Flotation System 4-17

4-11 Overview of Biological Treatment Methods 4-18

4-12 Estimated Costs for an Activated Sludge System 4-23

xv i --Tab1 e Page 4-13 In-Process Recovery Methods for Metal , Plating Wastewater 4-30

4-14 Typical Costs for Drag-out Reduction and Drag-out Solution Management 4-35

4-15 Volume of Hazardous Waste Produced and Fraction Incinerated in 4-51 Individual Countries

4-16 Comparison of Thermal Treatment Techno ogies 4-52

4-17 Design Parameters of Commonly-Used Inc nerators 4-53

4-18 Types and Quantities of U.S. Incinerators in Use 4-55

4-19 Costs Charged for Incineration at Commercial On-Site Facilities 4-58

4-20 Incineration vs. Treatment: Range Estimated Post-RCRA Charges for 4-59 Selected Waste Types

4-21 Potential Applications of an IR Furnace 4-62

4-22 Cost, Energy, Material , and Heat Balance Estimates for S1 udge 4-65 Incineration in an Infrared Furance; Shi rco Inc.

4-23 Comparison of Thermal Treatment Technol ogies 4-77

4-24 Compounds Reported to be Decomposable by Ozonation 4-79

4-25 Capital and Operating Costs for Chlorination and Ozonation Systems 4-84

4-26 Cost Estimate for Removal of Phenol by Ozonation 4-85

4-27 Applications of Commercially Available Membrane Materials 4-88

4-28 Economics of Reverse Osmosis System for Nickel Salt Recovery 4-89

4-29 Advantages and Disadvantages of Control Technol OgieS 4-90

4-30 Types of Remed a1 Action Employed at a Sample of Uncontrolled Sites 4-92

4-31 Summary Compar son of Relative 1985 Cost of Stabilization/ 4-96 Solidification A1 ternatives

4-32 1982 Cost Estimates for Five In-Situ Vitrification Large-Scale 4-97 Configurations

4-33 Major Industries Using Koch Ultrafiltration to Clean up Wastewater 4-103

4-34 Operating Characterisitcs, UF Oil Emulsions 4-107

xvi i Tab1 e -Page 4-35 Microf ltration System Performance 4-108

4-36 Operat ng Cost Analysis for the Processing of Flexographic Ink/ 4-109 Starch Adhesive Washwater

4-37 Investment Analysis , F1 exographic Ink/Starch Wastewater 4-110

4-38 Chemical Contaminants Treatable by UV Destruction 4-112

4-39 Specifications on Ultrox Pilot Plant 4-114

4-40 Costs of a Typical WAO System 4-118

5-1 Summary of Generation and Inventories of Nuclear Waste 5-3

6-1 Total Quantities of Recycled Material (U.S., 1984) 6-4

6-2 Energy Savings Through Recycling of Waste Materials 6-5

6-3 Estimated Changes in Waste Generation Paterns, 1983 and 1990, by 6-7 Major Industry Group Under A1 ternative Cases

6-4 Estimated Incremental Hazardous Waste Management Expenditures Under 6-8 the 1984 RCRA Anendments as a Percent of Estimated 1990 Profits by Major Industry Group Under A1 ternative Cases

6-5 Estimated Changes in Waste Generation Patterns 1983 and 1990 Randed by 6-10 Waste Quantity, under A1 ternative Cases

6 -6 Estimated Targets for Water Reduction and Material Recovery Through 6-11 Improved Industrial Processes

6-7 Chemical Composition of Dust form Electic Arc Furnaces 6-22

6 -8 A1 urni num Scrap Processing Flow 6-30

7-1 Water Disinfection 7-2

7-2 Disinfectants 7-4

7 -3 U.S. Potable Water Treatment Plants Using Ozone 7-5

7 -4 Comparison of Costs for Disinfection by Chlorine, Chloramines, 7-8 Ozone and Chlorine Dioxide

8- 1 Summary of Key Federal Laws dnd Responsible Agencies Related to the 8-2 Control and Regulation of Hazardous and Toxic Materials

xvi ii Tab1 e

8-2 Examples of Exemptions from Federal Regulation as Hazardous Waste 8-4

8-3 Summary of EPA Regulation and Guideline Schedule: LUST Program 8-4

8-4 New EPA Activities Mandated by 1984 RCRA Amendments 8-7

9-1 P1 anned EPRI Expenditures for Waste Research 9-1

9-2 EPRI R&D Projects 9-3

9-3 Project Numbers of EPRI Waste-Re1 ated Research 9-6

9-4 EPA Extramural Hazardous Waste Research Budget 9-8

xix

Section 1

S UMMAR Y

The growing problem of waste and water management is a source of great controversy and concern in today’s highly industrialized society. Stricter environmental protection regulations and the decrease of available space for waste disposal has resulted in the implementation of innovative waste processing technologies in order to comply with new regulations and higher costs of waste disposal.

This study examined the use of electrotechnologies in waste and water treatment. Toward this end, an assessment was made of the kinds and quantities of wastes and water treated and the state-of-the-art of treatment techno1ogies. Current research and development programs were identified within the Environmental Protection Agency (EPA) , the Electric Power Research Institute (EPRI) , and private industry. Also, current regulations were reviewed to determine their impact on the research and implementation of waste and drinking water treatment technologies.

Three major areas of waste treatment were identified to have opportunities for electrotechnologies R&D: hazardous waste destruction, tertiary treatment of waste water, and recovery of metals from waste streams. No research opportunities for EPRI were identified in the area of water treatment for public consumption.

STUDY APPROACH

Figure 1-1 is a graphic depiction of the flows of water and wastes to and from the residential , commercial , and industrial sectors of society. For this study waste flows were broken down into 2 major categories: 1) municipal and 2) industrial wastes. Further classifications apply to each category.

Municipal wastes can be further categorized as either solid (Municipal Solid Waste (MSW)), or wastewater (sewage). Industrial wastes encompass those from manufacturing, Standard Industrial Codes (SIC) 20-39; agriculture, SIC 01; and mining SIC 10- 14. The quantities of wastes generated in these categories are shown on Table 1- 1. As can be seen, the majority of current waste management technologies involve

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1-2 Table 1-1

SUMMARY OF WASTE GENERATION QUANTITIES AND DISPOSAL METHODS

Approximate Annual Quantities (1984) Primary Disposal Type of Waste (million Metric Tons) Methods

Muni cipal Sol id 170 Landfi 11 Liquid 10 (trillion gal) Activated S1 udge, Dewatering followed by 1 and appl ication

Industria1 Non-Hazardous Man ufactu ri ng 393 Landfill (on- & off-site) Ag r i c ultu r a1 2,800 Field application Mining 2,000 Landfi 11

Industrial Hazar ous Manufacturing9 41-267 On- & off-site landfills, incineration

1 - This range represents the uncertainty in the definition of hazardous and non-hazardous wastes.

‘II il I1 1’ disposition directly in an on- or off-site landfill. One of the purposes of this study was to identify alternative methods to direct disposal which include: waste concentration, waste destruction, and resource recovery.

For the purposes of compl eteness, nuclear wastes and disposal technol ogies were identified. However, this study did not cover the emissions of gaseous wastes, primarily SO,, NO,, hydrocarbons, and vapors from volatile liquids. These emissions were not covered because the treatment technologies for these wastes do not involve the consumption of large quantities of electrical power. On the other hand, treatment of water supplied by public water utilities was included, since electricity requirements are high in this industry.

According to the above definitions the study was broken down into six major areas: municipal wastes, industrial non-hazardous wastes, industrial hazardous wastes, nucl ear wastes, drinki ng water, and resource recovery. The 1 atter topic incl uding technologies that apply to all of the previous topics. Within each task the following information was gathered: quantities of wastes generated, types of wastes generated, current disposal or treatment technol ogies, research on promi sing treatment technol ogies , and energy usage for current and promising technol ogies.

In addition, consideration was made throughout the study of federal and state legislation which could affect the research of treatment technologies. The most important of these laws being the Resource Conservation and Recovery Act (RCRA) initially passed by the federal government in 1976 but with recent amendments in 1984 that have severely restricted the use of landfills, hence requiring a greater degree of waste treatment. As the study bore out, increased treatment will increase the use of electricity. This report is organized into individual sections for the individual tasks.

SUMMARY OF RESEARCH OPPORTUNITIES

Three areas of waste disposal offer research opportunities involving the use of electrotechnol ogi es.

Hazardous Waste Treatment

Hazardous waste treatment was the primary target of the 1984 RCRA Amendments, which were intended to increase the amount of hazardous waste treatment and reduce the

number of landfi11s for both hazardous and non-hazardous wastes. .~

1-4 Since many hazardous wastes are chlorinated organic molecules, as exemplified by PCBs (polychorinated biphenyls) , they can be incinerated by combustion or pyrolyzed by a thermal energy source, such as plasma or infrared energy. There are many advantages of pyrolysis when compared with incineration. In pyrolytic systems, the process products are the elemental precursers of the molecules destroyed, hence emissions from the pyrolytic device are primarily hydrogen, oxygen, carbon and chlorine,

In a combustion process, traces of several hundred organic compounds are typically found in the flue gases due to incomplete combustion, either because of flame quenching near a cold surface or incomplete mixing inside the incinerator. Pyro- lytic systems operate at higher temperatures than combustion systems, have longer residence times and involve much simpler reaction schemes since only the thermal decomposition of the long chain molecule is invloved, compared with the oxidation in a combustion reaction.

This study identified plasma systems as a possible area where EPRI may have some impact, in part because of EPRI 's extensive know1 edge of plasma systems.

One method of concentration of hazardous wastes is through electrochemical means. Electrochemical concentration including electrodialysis, electrolytic processes and electrophoresis, is attractive due to the numerous applications in the metals treating and finishing industry. These processes use an electric field as the driving potential to capture desired species. In the case of electrodialysis and electrophoresis, membranes are also used to improve the selection process. Waste waters from metal finishing processes can be treated to remove any hazardous metals prior to discharge to the public water system. EPRI may wish to disseminate information on these electrochemical methods for waste water treatment or provide suppor for a demonstration plant installation of such a system.

Another successful method of separating hazardous materials for further treatment in pyrolytic or incineration systems or possible burial in landfill is via freeze con- cehtration. This technology is promising because it can be used for a wide variety of liquid hazardous wastes and also for non-hazardous wastes. It may be beneficial for EPRI to aid in the development of this process to treat hazardous wastes.

Waste streams containing moderate 1 eve1 s of both organic and inorganic materi a1 S can be treated by a new process of supercritical fluid oxidation. This process is based on the recent discovery that organic materials when subject to conditions under

1-5 which water is supercritical (>218 atm, >374"C), will oxidize to carbon dioxide and water. Pending results from current bench-scale tests of the process, EPRI could conceivably faci 1 itate the next phase of techno1ogy devel opment.

A similar process for hazardous waste destruction is wet air oxidation. In this process, oxygen is mixed with the waste stream at elevated temperature and pressure ~ to oxidize organics. The process is currently being used in several waste treatment systems. As with the other new technolyies being developed commercially, EPRI could become involved in an analysis of several specific sources and quantities of wastes that could be technically and economically managed by the treatment process.

Treatment of Wastewater

One of the results of the 1984 RCRA ammendments was the requirement of greater wastewater treatment prior to discharge into public rivers, lakes, and oceans. In order to comply with these legislative rules, a number of treatment technologies are available to municipalities. These include: aeration, ion exchange, reverse osmosis, ultrafiltration, and ultraviolet radiation. These technologies are all electricity intensive and efficient in the capture or destruction of low concentration wastes, which must now be treated according to the KCRA amendments of 1984.

In the case of aeration, research is needed in the basic optimization of the oxygenation efficiency. For ion exchange, reverse osmosis and ultrafiltration, membrane development is needed to adapt these technologies to widespread use in wastewater treatment.

Resource Recovery

In compliance with RCRA, a higher degree of resource recovery will result. Typical- ly the materials that will be recoverable are glass and metals, with emphasis on the higher value-added rare and noble metals. Paper is also a good candidate for recovery if it is kept separate from other wastes.

Some of the technologies available for metals recovery are: plasma-arc treatment for zinc recovery from electric arc furnace dust , and reverse osmosis and elect rodi dly- sis for recovery of metals from metals finishing sludges. EPRI's potential role could be to aid in the further development of these processes. EPRI is currently supporting a demonstration for recovery of zinc from electric-arc furnace dust.

1-6 Only approximately ten percent of the domestic consumption of glass containers are recovered for recycling. This compares with thirty-five percent for steel and thirty percent for aluminum. An increase in glass recycling (as with both aluminum and steel) potentially could increase the demand for electricity.

-__-Concl usi on For each of the areas mentioned above, two general approaches can be taken. The first is to fund or cofund, one or more demonstration projects at commercial scale to prove the viability of the technology. The second option is to concentrate on technol ogy-t ransfer .

Due to the high costs, and licensing difficulties associated with demonstration plants in waste treatment, especially hazardous wastes, it is recommended that the second approach be taken.

1-7

Section 2

MUNICIPAL WASTES

MUNICIPAL SOLID WASTE (MSW)

Characterization and Quantities of-- MSW

The current rate at which municipal solid waste (MSW) is generated in the United States is between 160 and 180 million metric tons annually. Although this figure represents a small percentage of the over 5 billion tons of solid waste produced annually in the U.S., the variety of constituents and the escalating difficulties associated with handling and disposal of MSW are a major source of concern to environmental ists and many municipal ties.

The national average composition of municipal solid waste is shown in Table 2-1. Organic materials comprise the largest portion of MSW, followed by metals and glass.

__I_-Management and Disposition of Municipal Sol id Waste

Economical and environmentally sound methods for disposal of MSW are the focus of a great deal of attention. The concern is due to a number of factors: a steady increase in the generation of MSW, a tightening of regulations regarding municipal landfills, and a lack of additional available landfill space. Figure 2-1 illustrates the flow of MSW from generation to disposal, and Table 2-2 presents a breakdown of disposal methods used for MSW.

Landfills. The largest portion of MSW is currently being disposed of in landfills, and such will remain the primary method of disposal in the near future. However, siting new landfills is becoming more difficult and more costly due to stricter federal and state environmental protection regulations. Table 2-3 illustrates the escalating costs associated with development of landfi 11s.

The increase in landfill development costs is the result of newly implemented, stricter environmental control and protection measures. These new requirements may include any combination of the following:

2-1 Table 2-1

COMPOSITION OF MUNICIPAL SOLID WASTE BY MATERIAL TYPE

Mater ia 1 Percentage of Total Waste _I____----.--.--.--.-- Paper 38.5 Foodwaste 16.8 Yard Waste 13.2 Metals Ferrous 8.0 A1 uminum 1.0 Other Nonferrous 0.2 G1 ass 9.0 Plastics 4.1 Wood 3.0 Rubber 2.0 Textiles 2.0 Misc. Inorganics 2.0 Leather 0.2

Source: Ref. 1 and Ref. 2

Table 2-2

DISPOSITION OF MUNICIPAL SOLID WASTE IN THE U.S.

Disposal Methods No. of Facilities % of Disposal _I---- ___-1-1-- --.- I- Landfi 11s 11,000 - 12,000 90 Resource recovery 120 - 130 10 - Waste to energy (4) - Recycl ing (6)

--- Source: Ref. 1 and Ref. 2

2-2 Solid Waste Generation 1

Fhseparation

Delivery lo recycling Collection Transfer centers station

Material Material recovery recovery industries (optional) 1 Shredding/ Processing

Material ’ separation

Energy Residue recovery

Baling c,Landfill

Figure 2-1. Solid Waste Handling Flow Chart

Source: Ref. 3

2-3 Table 2-3

LANDFILL DEVELOPMENT COSTS - PAST AND PRESENT

1975 1985 Cost Item ($/ton 1 % ($/ton) %

Pre Development Costs 0.25 5.9 1.30 a. 7

Site Preparation and 0.52 12.3 4.90 32.7 Construct ion Costs

Site Operation 3.2 75.7 6.50 43.3

Site Closure 0.26 6.1 0.70 4.6 Long Term Care -0.0 0.0 1.60 --0.7 TOTAL 4.23 100.0 15.0 100.0 (Excluding Profit)

.- Source: Ref. 3

2 -4 C1 ay 1 iner construction

Leachate coll ection systems

Longer and more compl icated permitting processes

Owner responsibility for facilities during and after site operation

Leachate treatment

Gas coll ection systems

(Currently there are 75 operational gas recovery sites in the U.S., with a total annual output of 200 to 500 trillion BTUs)

Envi ronmental monitoring (groundwater, gas, ai r, surface water)

Table 2-4 shows some estimated costs for a new land disposal site.

Resource Recovery

Due to the increasing volume of refuse generated and the rising cost of landfill disposal , resource recovery systems are rapidly becoming the economical and practical solutions to the refuse disposal problem in the U.S. Typically, resource recovery serves two separate but interrelated functions, that is, as a service handling refuse and waste, and as a waste-to-product business. The service function of collecting and disposing of trash is the the overriding requirement of the municipalities, while the business function requires that the waste be converted to useful products which are sold to pay for the cost of the system. The product(s) of a resource recovery plant may include any combination of ferrous metal, aluminum, brass, bronze, zinc, copper, coins, glass, or energy.

Most waste-to-energy plants are built today from the service function perspective, where the capacity to dispose of waste is more important than producing a marketable product. Because of this orientation, waste-to-energy plants require a disposal fee as well as income from energy and material sales to repay their cost of operations .

Of course, total resource recovery is not possible; there is always something to be discarded (combustion residues, dirt, etc.) and the only practical way to do so is in a landfill.

However, the more densely-populated areas of the country are running out of landfill space, leaving resource recovery as their only viable option for solid waste disposal. Currently, there are 128 resource recovery plants in the United States,

2-5 Table 2-4 NEW TYPICAL COST REQUIREMENTS FOR A LAND DISPOSAL SITE

(Five-Foot Clay Liner, Leachate Collection System, 40-Acre Site, 1,000,000 Tons/2,000,000 cu. yd., 15-Year Site Life, 30-Year Long-Term Care Period, And On-Site Clays) I Construction Item Unit Costs Total Cost 5' Clay Liner Placement Clay Liner: ($6.00/cu. yd.)(450,000 cu. yd.) = 2,700,000 $3,000,000 (includes protective sand Sand Blanket: ($4.00/cu. yd. )(75,000 cu. yd.) = $300,000 blanket from off-site source) Leachate Collection System Leachate Collection and Transfer Piping: ($20.00/LF) $400,000 (12,000 LF) = $240,000 I Manholes: ($2,00O/ea.)(l5) = $30,000 10,000 gal.'Leachate Storage Tank:$20,000

N Lysimeter Detection System: ($2,0OO/ea.)(5) = $1 0,000 I ol Clean-Outs, Valving and Other Appurtenances:$l 00,000 Leachate Treatment (ave. ($0.03/ga1.)(1,400,000 gal./yr.)(45 yr.) = $1,890,000 $1,890,000 production rate of leachage produced over site life)

Environmental Monitoring Ground Water Monitoring, Leachate Monitoring, gas $765,000 Monitorina ($17,0OO/yr.)(45 yr.) = $765,000

Source: Ref. 3

il I' of which 87 are operational and 41 are under construction. In addition, there are 124 resource recovery facilities in the early stages of conceptual planning with roughly one half planning to engage in some degree of material recovery activity.

Refuse-to-Energy Systems

In the past, constructing a refuse-to-energy (RTE) plant was a risky business, but today MSW can be successfully burned to produce steam, due to advances in plant design, construction, and operation. The relative energy values of MSW, refuse- derived fuel and conventional fuel are compared below. Considering the relatively high Btu content of MSW and the vast quantities generated annually, it becomes obvious that there is great value inherent in the RTE systems for both producing energy and providing an alternative to landfills.

Energy Source Energy Value (Btu/l b)

Municipal Solid Waste 4,500 Ref use-Deri ved Fuel 5,000 - 7,000 Coal 10,000 - 14,000 Wood 4,700 Peat 3,200 Natural Gas (per ft3) 1,200

Source: Ref. 1 and Ref. 2

There are three basic types of RTE systems: mass burn, refuse-derived fuels (RDF), and modul ar systems.

0 Mass burn plants incinerate raw refuse as delivered to the plant, with some recovery of ferrous metals from the ashes. Currently, 37% of existing RTE plants use some form of this technology, while 61% of those in advanced planning stages and 54% of those on the drawing boards plan to do so. Already, this is the primary method used for incinerationlenergy recovery in Japan and Western Europe. The total capacity of mass burn plants in the United States is over 5 million metric tons per year. The estimates for electricity production by these plants are between 280 and 350 MW. The total capacity is expected to exceed 40 million metric tons annually by the year 2000. This is equivalent to 20% of the projected total MSW generation rate for the year 2000. Figure 2-2 shows a schematic drawing of a water wall mass burning furnace. According to manufacturers, the smallest economical size for this system is 200 tons per day. Signal Systems has the largest share of the market for mass burning systems, while other market leaders include Clark-Kenith, Ogden Martion and MontenayIMors Bougl er.

2-7 2 -8 0 Refuse-derived fuel (RDF) facilities consume a prepared material which is produced from MSW through size reduction and removal of non-combustibles. The fuels produced may appear either in a loose (uncompacted) form or in a densified (pelletized) form. The energy requirement for producing RDF ranges from 0.6 to 0.7 kWh/ton for magnetic separation through 1 kWh/ton for screening, 4 to 5 kWh/ton for air classification, up to 17 to 18 kWh/ton for shredding. Of course, multiple screening stages could improve the plant efficiency drastically; for example, employing pre-trommel ing to remove bottles and cans before the refuse is shredded would reduce the quantity of fine glass and metal that is retained in the products.

The pl ants with moderate processing complexity are the most successful operations. Complex RDF processing plants produce a high quality fuel but the plants are generally inefficient, although this is more a function of equipment breakdowns than a problem with the processes themselves. Twenty-five percent of the resource recovery plants which began operation before 1985 were involved in RDF production; of those currently being built or in stages of initial testing, 23% will produce RDF; and of those currently under dis- cussion, 14% are conceived as becoming RDF producers. Currently, there is an installed capacity of over 6 million metric tons per year at RDF facilities, producing between 300 to 400 MW of electricity. By the year 2000 the capacity is expected to exceed to 20 million tons per year (10% of the projected total MSW generation rate for the year 2000). Figure 2-3 is a schematic diagram of an RDF-burni ng system.

The electric utilities have been experimenting with cofiring of RDF in their boilers. However, the results have been less than satisfactory. Cofi ring has resulted in the following effects: - A decrease in boiler effiency due to high moisture and ash content of RDF.

- A decrease in ESP efficiency due to increases in particle size and generation of fly ash.

- Unit derating due to increased flue gasses.

- An increase in boiler slagging. - Bottom ash handling problems as a result of the need for more frequent ash removal.

Market leaders in RDF systems include Babcock and Wilcox, Combustion Engineering, Foster Wheeler, Riley Stoker, and Detroit Stoker.

0 Modular systems burn unprocessed refuse and are used primarily for smaller applications of less than 200 tons per day compared to over 200 tons/day capacity for mass burn systems. Presently, 34% of existing plants, 17% of those under construction, and 32% of those in the conceptual design phase use this technology. The total existing capacity of modular systems is in excess of 1 million metric tons per year and it is expected to increase to 55 million metric tons per year by the year 2000. The current total electricity production by modular systems is between 70 to 100 MW per year. Consummate Systems is the market leader, followed by C1 ean Air, Vicon/Enercon, and WIDJAC.

2-9 Bag House Cyclone Electrostatic Precipitator

A c I &-- Secondary Storage Boiler I I Shredder

Plant Use Generator

1 I-~xportPower MSW ,Tipping + Primary Magnetic Storage Air IN Floor Shredder --.* Separator + - Classifier

To Tipping (Ferrous)Scrap Trommel -Ab Floor

Mixed Magnetic Magnetic Aluminum - Colored 4 Separator c Glass Separation Separator

Figure 2-3. Schematic of a RDF Burning System for Power Generation Source: SAIC Average operating capacities of existing resource recovery plants is reported to be as high as 82%, as measured by the ratio of actual daily throughput to plant design capacity. The highest capacity was found among modular mass-burning facilities (93%) and the lowest among RDF plants (73%).

Private firms own (42%) and operate (64%) the majority of the 128 plants already in existence or under construction. However, it should be noted that private firms will own 68% of the 41 plants currently under construction or in the initial testing stages, and will operate fully 87%. The trend toward private ownership and/or operation can be explained by larger, more expensive facilities being planned; local governments are therefore turning to private sector capital and expertise. Existing plants are more likely to produce steam while plants under construction are more likely to lean in the direction of electricity alone or steam and electricity. The total system sales over the 1986-2000 period are expected to exceed $18.5 billion.

MUNICIPAL WASTEWATER

There are approximately 15,000 pub1 icly-owned treatment works (POTWs) that treat residential commercial, and industrial wastewaters in the U.S. Approximately 10% of these plants treat over 82% of all industrial wastewater discharged to POTWs in the U.S. The total flow of waste streams is estimated to be approximately 26,700 million gallons per day. This represents a sewered population of over 165 million, or 69% of the total U.S. population, who receive some form of centralized treatment. The rising concern over environmental safety is certain to increase this percentage, with a projection of 90% by the year 2000. Energy expended on treatment of wastewater in the United States can be expected to increase accordingly.

One serious problem for POTWs in the U.S. is the discharge of hazardous wastes There is a regulation known as Domestic Sewage Exclusion (DSE) which provides that a hazardous waste when mixed with a domestic sewage is no longer considered a hazardous waste. The exclusion allows industries connected to POTWs to discharge hazardous waste to sewers containing domestic sewage without having to comply with certain RCRA generator regulations, such as manifesting and reporting requirements.

A study conducted by the EPA has identified over 160,000 industrial and commercial facilities discharging waste streams that contain hazardous wastes. Together, these facilities discharge an estimated 3,200 million gallons per day of process Waste- water, or approximately 12% of the total POTW flow.

2-11 Management Technologies for POTWs

Figure 2-4 illustrates the flow of wastewater from generation, to treatment, to final disposal of the resulting sludges and water effluent streams. Presently, about 70% of the POTWs have capabil ities for secondary treatment or better , but these facilities serve only 50% of the entire population. However, coverage by POTWs is being expanded. In the year 2000 approximately 88% of the U.S. population will be served by treatment plants with secondary treatment levels or better; furthermore, the general trend is toward higher levels of treatment.

The basic objective of wastewater treatment is to remove suspended matter and organics from water and to concentrate and stabilize biodegradable constituents prior to ultimate disposal. In order to stabilize biodegradable organics, they must be concentrated to a more stable, non-biodegradable (refractory) form by oxidation. In most industrial and municipal wastewater treatment systems , the basic process can be categorized by one or more of the following techniques:

0 Separation or concentration of pollutants

0 Oxidation or stabilization of organics

0 Disinfection

0 Detoxification

The proportions of the major constituents of municipal wastewater are as follows : approximately half of the total solids are combustible or volatile materials; and about 50% of the organic fraction are biodegradable constituents, thus, about 25% of the total sol ids are biodegradable materials. Primary sedimentation removes settle- able materials (>lo m) , which includes biodegradable and nonbiodegradable compounds. Combined primary and secondary treatment removes additional organic and inorganic compounds. Tertiary treatment can also be used to meet special treatment situations.

Tables 2-5 and 2-6 list the major processes employed in wastewater and sludge treatment, and the energy consumption associated with each process. In these tables energy estimates are referenced to fossi 1 fuel equival ents , using a fossi 1 fuel -to- electrical conversion efficiency of 32%. In addition, process energy requirements include energy consumption for on-site operations as well as that consumed in the production of chemicals and other materials which are utilized during treatment. These tables illustrate that such stabilization processes as activated sludge, incineration , aeration ponds , and aerobic and anaerobic digestion are energy- intensive primarily due to the pumping energy required. For aerobic processes,

2-12 WASTEWATER WASTEWATER SLUDGE SLUDGE SLUDGE GENERATION TREATMENT TYPE TREATMENT USE / DISPOSAL

Ddor Control and Pathogen Reduction * Stabilization

Land Application Water Removal, Distribution and Volume Reduction, I and Possibly Mass Reduction Incineration Thickening Ocean Disposal Conditioning Dewatering N I Pretreatment Drying w W (Advanced) Tertiary

.....>.:.:.:...... \ ..... IEffluent ...... :*...... :.:::::::.::::.>-. Discharge I ..:.:...... = Wastewater

.) = Sludge

Figure 2-4. Generation, Treatment, and Disposal of Municipal Wastewater/Sludge

Source: Ref. 5

il I' Table 2-5 ANNUAL ENERGY CONSUMPTION FOR WASTEWATER TREATMENT -. LO wted for 7000 Energy consumption Energy consumption (X lo9 Btulyr) (X lo9 Btulyr) Average Total Average Total Treatment procw Number flow (mgd) flow (mgd) Electrical Fuel Total Number flow (mgd) flow (mgd) Electrical Fuel Tom

1. Pumping. TH - 35 It 5.700 3.1 17,764 13,140 13,140 10.420 2.2 23.284 17,230 17,230 2. Preliminary. buscreen 8.174 2.7 22,231 122 122 14.419 1.9 21,987 215 215 3. Preliminary, grit removal 3.867 4.8 18.416 442 442 7.142 3.3 23.699 1,070 1,070 4. Preliminary, comminutors 3.492 2.5 8,819 226 226 5,791 2.0 11.457 378 378 5. Preaeration 395 12.1 4.761 1,680 1.680 533 10.6 5.666 2.060 2.060 6. Primary sedimentation 5,736 3.6 20.858 - 631 9,360 2.8 25.753 944 94 4 7. Trickling filter, rock 2.778 1.5 4.255 4.681 4.681 2.957 1.7 5,002 5.502 5,502 8. Trickling filter, synthetic 85 3.1 260 501 501 194 5.8 1.123 2.162 2,162 9. Rotating biological contactor 71 1.1 75 171 171 555 2.3 1.250 2,900 2.900 10. Act. sludge, conventional 3.816 5.0 19.083 50.400 50.400 7,372 3.7 27,004 71,300 7 1,300 11. Act. sludge, high rate 34 2.3 770 1.950 1,950 61 1.8 1,118 2.830 2.830 12. Act. sludge. cont. stab. 873 2.6 2,256 6,200 6,200 1.197 2.4 2,866 7.880 7.880 13. Act. sludge. ext. air 1.902 0.6 1,197 8.340 8.340 5,255 0.5 2.527 17,600 17,600 N 14. Act. sludge, oxygen 45 36.0 1.610 2,660 2.660 120 41.0 4.898 8,080 8,080 +I 15. Filtration 1,177 1.8 2,155 498 498 5.99 1 2.0 11,930 2,760 2.760 P 16. Act. carbon, granular 13 9.9 129 121 809 47 15.0 713 669 4.470 17. Act. carbon, powdered 3 1.8 53 - 1 15 - 140 - 4 18. Lime, two-stage 19 3.2 60 86 87 82 3.2 265 379 383 19. Lime, one-.tlge 45 4.2 190 77 80 195 6.3 1,227 499 520 20. Recarbonation 14 5.6 78 146 146 81 3.8 309 578 578 21. Alum 294 4.9 1.448 573 573 943 4.3 4,016 1.590 1,590 22. Ferric chloride 183 7.5 1.378 344 344 399 5.0 2,012 502 502 23. Nitrification 188 4.1 775 1,110 1,110 1,646 5.2 8.515 12,200 12,200 24. Denitrification 38 8.7 332 365 365 279 6.2 1,742 1,920 1.920 25. Breakpoint chlorination 25 8.3 207 1,690 1,690 191 6.5 1,234 10,100 10,100 26. Ammonia stripping 24 1.2 29 198 198 150 1.5 221 1,510 1,510 27. Chlorination 6,213 2.3 14.036 11,600 11.600 13.441 1.5 20.353 16.800 16,800 28. Ozonation 12 4.3 51 8 8 36 13.0 460 70 70 29. Land treat., pri. effluent 90 0.3 26 77 77 142 0.3 44 131 131 30. Land treat., sec. effluent 305 1.7 514 1,530 1,530 819 1.5 1.245 3,700 3,700 31. Land treat., pond effluent 93 0.5 45 134 134 151 0.5 81 24 1 24 1 32. Aer8ted pondallagoonr 6.831 0.5 3.322 27.400 27,400 11.850 0.4 4.659 38.400 38.400 33. Oxidation ditch 337 0.4 131 663 663 925 0.4 392 1,980 1,980 34. Post aeration 432 2.9 1,260 182 182 1.547 2.4 3,639 5.025 5,025 35. Outfall pumping, TH * 10 ft 207 8.3 1,715 363 363 488 8.4 4.104 868 868 Subtotal. liquid processes - - - 138.309 139.002 - - - 240,073 3,829 243.902

-- Source: Ref. 6 Table 2-6

ANNUAL ENERGY CONSUMPTION FOR SLUDGE TREATMENT

In use 1978 Estimated for 2000 Energy consumption Energy consumption (X lo9 Btulyr) (X lo9 Btu/yr) Average Total Average Total Sludge treatment process Number flow (mgd) flow (mgd) Electrical Fuel Total Number flow (mgd) flow (mgd) Electrical Fuel Total

36 Aerobic digestion 2,287 1.6 3,568 20,400 - 20,400 5,476 1.2 6,452 36,900 - 36.900 37 Aerobic digestion. oxygen 40 2.2 89 407 - 407 79 3.8 302 1,380 - 1,380 36 Composting 10 35.0 354 - 28 28 30 28.0 845 - 68 68 39 Anaerobic digestion 4,714 3.3 15,657 10,300 27 10,327 6,747 3.0 19,900 13,130 34 13,164 10 Heat treatment 148 15.0 2,163 - 10.600 10,600 218 20.0 4,272 - 27,900 27,900 4 1 U et air oxidation 45 12 0 525 - 2,210 2,210 53 12.0 635 - 2.670 2,670 42 Chlorine oxidation 28 10.0 295 633 - 633 50 7.6 382 819 - 819 43 Lime stabilization 50 8.0 399 105 444 549 94 7.1 670 177 746 923 14 Solar,air drking 6,291 1.7 10,704 188 - 188 11,000 1.3 13.894 244 - 244 45 Vacuum filter 1,042 9.3 9,656 2,180 2,005 4,185 1,921 7.5 14,412 3,250 2,993 6,243 46 Centrifuge 155 12.0 1,910 4 20 - 420 253 18.0 4,673 1,030 - 1,030 Iv 17 Filter press 54 5.8 313 1,067 65 1,132 158 9.3 1,462 4,985 305 5,290 I 46 Dewatering, other - - w 24 16.0 375 163 163 34 12.0 420 182 182 Cn 19 Gravity thickening 557 13.0 7,199 79 - 79 940 11.0 10,048 115 - 115 50 Air flotation 158 16.0 2,569 1,980 - 1,980 313 16.0 5,112 3.940 - 3,940 51 Incineration, MH and others 336 16.0 5,462 210 29,100 29,310 482 17.0 8,165 314 43,540 43,854 52 Incineration. fluid bed 15 8.0 120 356 512 868 18 11.0 189 561 806 1.367 53 Pyrolysis 2 10.0 20 100 - 100 19 100.0 1,895 9,500 - 9.500 54 Recalcination 27 14.0 380 248 4,680 4,928 56 13.0 738 482 9,090 9,572 55 Landfill* 4,930 2.6 12,547 - 2,592 2,592 9.328 2.0 18,662 - 3,856 3.856 56 Landspread. liquid' 1,003 2.1 2,115 - 4,511 4,511 1,469 1.8 2,707 - 5.770 5.770 57 Landspread dewatered* 878 3.3 2,895 - 3,200 3,200 1,220 3.4 4,088 - 1,520 4,520 jb Trench' 4 47.0 284 - 727 727 11 26.0 291 - 745 745 59 Ocean, 50 mile 19 53.0 2,580 3,830 - 3,830 ------60 Digester gas utilization 173 9.9 1,711 - (2,723)t (2,723) 217 13.0 2,840 - (4,518) (4,518) Subtotal. sludge treatment - - - 42,666 57,978 100,644 - - - 77,009 98,525 175.534 Subtotal liquid processes - - - 138,309 693 139,002 - - - 240,073 3.829 243,902 Total 176,764 58,671 235,435 - - - 317,088 102,354 419,442

'Includes 20-mile round-trip truck transport tparentheses denote energy credit

Source: Ref. 6 devices such as submerged turbines (mixer and blower) are needed for oxygenation process. For anaerobic processes the major energy requirements are for heating, recirculation, pumping, and mixing. Altogether, the stabilization processes comprise about 70% of the total energy consumed by POTWs. Sludge dewatering and conditioning processes are also important, as they consume about 9-12% of the total demand. Conversely, preliminary and primary treatment processes are of 1 ittle sig- nificance relative to the total energy picture.

The advanced wastewater treatment and tertiary processes will represent a 1 arger fraction of the total energy consumption by POTWs in the future, as more stringent discharge requirements are anticipated to act as an impetus to their growth. This is illustrated in Tables 2-5 and 2-6 by the large increase in energy consumption for nitrification and other tertiary processes which are expected to be significant by the year 2000.

In order of precedence, the processes that will most likely contribute significantly to expected increases in energy consumption by POTWs in the period 1986-2000 are:

e Activated sludge

0 Conditioning and dewatering

0 Incineration

0 Anaerobic digestion

0 Tertiary treatment

0 Aeration ponds

0 Nitrification

It is estimated that the energy consumption for wastewater treatment and sludge disposal will increase by over 70% by the year 2000. This change is due to more treatment plants serving a larger population with more sophisticated and energy- intensive treatment. Higher degrees of wastewater treatment usually increase the quantity of the sediment deposited during the treatment of sewage. This sludge generally contains heavy growths of microorganisms as a result of aeration. For example, primary treatment typically produces 2,500 to 3,500 gallons of sludge per mil1 ion gallons of wastewater treated. Biological secondary treatment produces an additional 15,000 to 20,000 gallons of sludge per million gallons of wastewater treated, while tertiary treatment creates another 10,000 gallons per million gallons treated. In 1985 over 6.6 million dry metric tons of municipal sludge was disposed of in the U.S.

2-16 The stabilization, dewatering and conditioning processes (e.g., activated sludge, incineration, etc.) together comprise over 80% of the total energy consumed by POTWs. Therefore, the following sections will be devoted to describing them in more detail. The advanced wastewater treatment processes such as nitrification, reverse osmosis, and so on will also be discussed briefly as well.

Activated S1 udge

Overall , secondary wastewater treatment processes account for 44% of the total energy demand by POTWs. Approximately 70% of this usage is attributable to activated sludge processes, and the balance is distributed among trickling filters, ponds , ditches , etc. The activated sl udge process provides close contact between organic wastes and microorganisms while simultaneously transferring oxygen to the mixture in order to maintain sufficiently aerobic conditions. A dissolved oxygen content of from 1 to 2 mg/l is required in the reactor.

Aeration may be achieved either with mechanical aerators, or by bubbling through air, or in some recent designs, pure oxygen. Under these conditions microorganisms consume organics as a food/energy source. The resulting suspended sol ids comprised of 1 ime, dead microorganisms, refractory (non-biodegradable) organics, and inorganic solids are separated from the main flow stream by allowing them to settle out in the final clarifier. Eventually, the concentrated solids are either recycled to the aerobic reactor or disposed of as activated waste sludge. The conventional activated sludge process (Figure 2-5) is probably the most effective industrial and munici pal waste treatment process of a1 1. Tab1 e 2-7 summari zes pertinent information for assessment of activated sludge energy requirements.

-Condi t ioni ng/Dewateri ng

Dewatering processes reduce the amount of water in a sludge without significantly reducing the mass of solids; as such, it is purely a volume reduction process. Most sludge thickening and dewatering processes operate more efficiently when the sludge has been subjected to prior conditioning, typically with inorganic chemicals or thermal treatment. The energy required to produce consumabl es (chemicals) used in sl udge treatment processes is termed indirect. Energy requirements for thermal conditioning, which are significant, are represented directly in the in-plant energy budget.

In the following sections, the operation of major mechanical dewatering systems will be described.

2-17 ~- b Secondary + 2500 Iblday A* Effluent INFLUENT 25000 Ib/day

Secondary Sludge 7000 Iblday

Figure 2-5. Schematic Diagram of an Activated Sludge System

(See Table 2-7) Source: Ref. 6

2-18 Table 2-7

SUMMARY OF CONVENTIONAL ACTIVATED SLUDGE OPERATING CONDITIONS

F1 ow 10 mgd

Sol ids Retention Time (SRT) 4 days

Biological Oxygen Demand (BOD) (')

Influent 0.0025 1 b/gal 25,000 lblday

Effluent 0.00025 1 b/gal 2500 lb/d

Waste sludge 7000 1 b/d

Stabi 1 ized 15,500 lb/d

Oxygen consumption 15,500 lb/d

Oxygenation efficiency 0.36-1/1 kWh/l b 02

Miscell aneous energy requirements* 50 kWh/mg

Specific energy consumption+ 0.39-1.1 kWh/ 1 b BODL stab i1 ized 0.68-1.9 Btu/Btu stabilized

* Return sludge pumping and clarifier operations. ' Electrical energy fuel equivalents: 10,500 Btu/kWh; BEP (') stabilized (Btu/lb) = BOD stabilized (lboz/lb) x 6000 (Btu/lboz).

(1) An SRT of 4 days was assumed for this analysis. (2) Biochemical energy potential = potential heat released upon complete, biological oxidation of biodegradable organics.

Source: Ref. 6

2-19 Centrifugation. Centrifugal dewatering is a process which uses the force developed by rapid rotation of a cylindrical drum or bowl to achieve separation of solids and liquids. Basically, when a sludge slurry is introduced to the centrifuge it is forced against the bowl's interior walls, forming a pool of liquid. Density differences cause the sludge solids and liquids to separate as they are spun, whereafter they are discharged from the unit. There are several variations of centrifuges readily available, namely, basket bowl, disc-nozzle and solid bowl conveyor.

Solid Bowl Centrifuges. Solid bowl centrifuges are utilized more frequently than any other type, and they have the highest throughput as well as high solids concentration in the cake. Larger units are available with a bowl length of up to 3.6m (140in) and a handling capability of 19 to 441/s (300 to 700 gpm) per unit, depending on the slurry. The solid bowl centrifuge is a continuously operating unit. The centrifuge shown in Figure 2-6 consists of a rotating horizontal cylindrical bowl containing a screw type conveyor or scroll which also rotates, but at a slightly lower or higher speed than the bowl. This difference in speed is required for the conveyance of solids towards one end of the centrifuge while the liquid fraction is discharged in the opposite direction. Recent advancements such as the use of replaceable ceramic tiles in low-G centrifuges (less than 1,100 Gs) and sintered tungsten carbide tiles in high-G centrifuges (greater than 1,100 Gs) have greatly increased the operating life prior to overhaul. Solid bowl centrifuges are typically capable of dewatering a 50/50 mixture of anaerobically digested primary and secondary sludges to a 15 to 21% solids concentration.

Secondary sludges result from secondary biological treatment and are much finer than primary sludge. They consist largely of cellular organic material with a density nearly equal to that of water and are much more difficult to dewater than primary sludges. Table 2-8 lists the advantages and disadvantages of solid bowl centrifuges.

Belt Press Filtration. A belt filter press continuously removes water from a slurry --1_-----1_ by pressing it between two moving belts of porous cloth. The filtration process itself includes three basic operational stages: chemical conditioning of the feed slurry, gravity drainage, and pressure filtration. Figure 2-7 shows such a belt press and the location of the stages. The units are available from many manufacturers in belt widths of 0.5 to 4m (1.6 to 13 ft), but the belt width having the longest service record is the nominal 2.0m size. The belt speed varies from 2.4 to 4.6 m/min (8 to 15 ft/min) for a dilute fragile slurry to about 9.1 m/hr (30 ft/hr)

2-20 COVER DEWATERWG BEACH

DIFFERENTIAL SPEED GEAR 8OX

MAIM DRNE

. .,...... : I FEED PPES ~ (SLUDGE AND CONDITIONING CMMICAU __

DSCtiARGE CAKE DtscnmE

Figure 2-6. Continuous Countercurrent Sol id Bowl Centrifuge

Source: Kef. 11

2-21 Table 2-8

ADVANTAGES AND DISADVANTAGES OF SOLID BOWL CENTRIFUGES

Adv an tages ---I- 1. Clean appearance, little to no odor problems.

2. Fast start-up and shutdown capabilities.

3. Can be operated either for thickening or dewatering. 4. Use of low polymer dosage when compared with other devices, with the exception of the basket centrifuge,

5. High rates of feed per unit.

6. Does not require continuous operator attention.

7. Can operate with a highly variable feed solids concentration on many sludge types.

~-Di sadvantages 1. Noise is very noticeable, especially for high-G centrifuges.

2. High power consumption for a high-G centrifuge.

3. Vibration must be accounted for in designing electronic controls and structural components.

4. Scroll wear can be a high maintenance item and requires skilled maintenance personnel.

5. A condition such as poor centrate quality can be easily overlooked since the process is fully contained.

2-22 Dry polymer

Water

discharge Belt wash

Figure 2-7. Belt Filter Press System

Source: Ref. 8

2-23 for a fibrous pulpy one. The belt materials most widely used are woven nylon and polyesters. Several machine variables including belt speed, tension, and type influence belt press performance. An increase in tension will increase the pressure on the slurry, but this may increase the rate of belt wear. Therefore, the tension in belts is limited to about 17.5 to 87.5 N/cm (10 to 50 lbs/in) of belt width. An increase in speed will reduce the retention time in the press and the throughput will thus increase; however, a lower solids concentration will result.

Belt filter presses will typically dewater a 50/50 mixture of anaerobically digested primarylsecondary sludges to an 18% to 23% solids concentration. Table 2-9 lists the advantages and disadvantages of belt filter presses.

Vacuum Filtration. A vacuum filter consists basically of a horizontal cylindrical drum which rotates partially submerged in a vat of sludge. The filter drum is divided into multiple compartments or sections by partitions or seal strips (Figure 2-8). A vacuum is applied between the drum deck and the filter medium, causing filtrate to be extracted and filter cake to be retained on the medium during the pickup and cake drying cycle. When ready, the cake of dewatered sludge is removed by a fixed scraper blade. Figure 2-9 illustrates the operating zones of a rotary vacuum filter.

The most common measure of filter performance is expressed in terms of kilo- grams of dry solids in cake discharged from the filter per square meter of effective filter area per hour. A typical range of vacuum filter yields for anaerobically digested primary and secondary sludge is about 17 to 19 kg/m*/hr (3.5 to 6 lbs/ft2/hr). Typically, a vacuum filter will produce a cake with a solids concentration of between 15 and 20% on a 50/50 blend of anaerobically digested primary and secondary sludge. The use of vacuum filtration in mechanical dewatering is decreasing due to recent improvements in the belt filter press and solid bowl centrifuge techno1 ogies. Table 2-10 1 ists the advantages and disadvantages of vacuum filtration.

Pressure Filtration. The filter press is a batch device used in industry to process sludges that are particulary difficult to dewater, or in areas where higher cake- sol ids concentrations are required. There are several variations in mechanical design and operating pressures, the most commonly used being:

0 Vertical plate filter press (municipal sewage)

0 Variable volume recessed plate filter press or diaphragm filter press (municipal sewage, steel industry slurries)

2-24 Table 2-9

ADVANTAGES AND DISADVANTAGES OF BELT FILTER PRESSES

Advantages

1. High pressure machines are capable of producing drier cake than any machine except a filter press.

2. Low power requirements; a typical 1 meter (3.2 foot) belt filter has only one 5-hp motor.

3. Low noise and vibration.

4. The operation is easy to understand for an inexperienced operator because all the parts are visible.

5. Continuous operation.

Disadvantages

1. Very sensitive to incoming feed characteristics and chemical condi tion ing . 2. Wash water requirement for belt spraying can be significant. The flowrate required for belt washing is usually 50% to 100% of the flowrate of sludge to the machine at a pressure of 100 psi or more.

3. Short media life as compared with other devices using cloth media.

4. Can emit noticeable odors if the sludge is poorle stabilized.

5. Typically requires greater polymer dosage than a centrifuge.

2-25 AIR BLOW-WCK LINE

Figure 2-8. Cutaway View of a Rotary Drum Vacuum

Source: Ref. 9

2-26 CAKE DRYING ZONE \

Figure 2-9. Operating Zones of a Rotary Vacuum Filter

Source: SAIC

2-27 Table 2-10

ADVANTAGES AND DISADVANTAGES OF VACUUM FILTRATION

Advantages

1. Long media life as compared with other devices using cloth media.

2. Continuous operation.

3. Low maintenance except in certain cases with lime conditioning. 4. Will continue to operate even if the chemical conditioning dosage is not optimized.

Disadvantages

1. High energy usage.

2. Vacuum pumps are noisy.

3. Can emit strong odors if the sludge is poorly stabilized.

4. Requires at least 3% feed solids to achieve adequate cake formation and discharge.

5. Lime and ferric chloride conditioning can cause considerable maintenance clean ing probl ems.

2-28 0 Roll er press (pul p and paper, peat dewatering)

Vertical Plate Filter Press. The vertical plate filter press consists of a set of vertical plates held rigidly in a frame and pressed together between a fixed and a moving end, with a filter cloth mounted on the face of each individual plate (Figure 2-10). The sludge is fed into the system at pressures of up to 16 atm (230 psi) so that the liquid passes through the cloth while the solids are retained to form a cake on the surface. The sludge feeding stops when the cavities or chambers between the trays are completely filled. The drainage from a large press can be on the order of 2.1 to 3.1 /s (2000 to 3000g/hr). This rate falls rapidly to 0.5 l/s (500g/hr) as the cake begins formation, and when it completely fills the chamber the rate is virtually zero. At this point the sludge feeding is stopped and the individual plates are moved, either manually or automatically, to allow the cake to fall out.

Variable Volume Recessed Plate. In a variable volume recessed plate or diaphragm filter press, sludge is pumped into the press at low pressure, about 7 atm (100 psi) , until the volume of the press has been filled with a loosely compacted cake. Then, the sludge pumping is stopped and the diaphragm is inflated by pumping in either air or water at pressures of up to between 15 to 20 atm (215 to 290 psi) for a preset time, after which the diaphragm is deflated and the press opens allowing the cake to drop out the bottom. Figure 2-11 shows the operational cycle for Ingersol 1 Rand ' s Lasta diaphragm press.

Roller Press. The roller press consists of two horizontal rolls mounted in a sealed vat, with one roll fixed and the other moveable to allow for variable nip openings. If the mat thickness varies, the roll automatically follows this change and maintains a constant nip load, resulting in a constant discharge of solids. The slurry enters the sealed vat and drains by pressure filtration and forms a mat on the roll surfaces which is carried forward into the nip by the rotation of the rolls. Within the nip the mat is further dewatered to the desired dryness of up to 40% solids. Immediately beyond, the solids are scraped off the rolls and guided into a top-mounted , screw-type shredder-conveyor from where the dewatered material is gravity-discharged at the rear end of the machine for ultimate disposal. The pressate flows through the roll faces and is discharged at the bottom of the press (Figure 2-12). Table 2-11 lists the advantages and disadvantages of Filter Presses.

2-29 m a, v) m W L a L W U c

mi 0 d I '. (u W L 3 cn *r LL

2-30 e e e e e e A- Filter clothe

D i a p h ragiii

Filtrate High pressure water

00 00 STEP 1 - LOW PRESSURE STEP 2 - COMPRESSION OF SLUDGE FI LTRATION BY THE DIAPHRAGM

>' >' ..

f :'X

\\/ 1: 1: Cake \y

STEP 3 - CAKE DISCHARGE STEP 4 - FILTER CLOTH WASHING

Figure 2-11. Operational Cycle for a Lasta Diaphragm Filter Press

Source: Ref. 11

2-31 ul m aJ L

2-32 Table 2-11

ADVANTAGES AND DISADVANTAGES OF FILTER PRESSES

Advantages

1. High solids content cake.

2. Can dewater hard-to-dewater sludges, a1 though very high chemical conditioning dosages or thermal conditioning may be required.

3. Very high solids capture.

4. The only mechanical device capable of producing a cake dry enough to meet landfill requirements in some locations.

Disadvantages

1. High capital cost. 2. Labor cost may be high if sludge is poorly conditioned and if the press is not automatic.

3. Noise level s caused by feed pumps can be very high.

4. Replacement of media is both expensive and time consuming.

5. Large quantitites of inorganic conditioning chemicals are commonly used.

2- 33 Performance Estimates of Dewatering Processes. Figures 2-13 and 2-14 illustrate ------^__--I-- .I_--- typical performance curves of various mechanical dewatering processes with different types of sludges. The solids concentrations given are not corrected for any inorganic conditioning chemicals, nor do they take into account the cost of chemical conditioning or the percent recovery obtained. The data are, however, based on reasonable levels of chemical conditioning and sol ids recoveries for the processes considered. Further information regarding various aspects of the dewatering processes is presented in Tables 2-12 through 2-15.

In order to assure compatibility with an ultimate disposal technique, careful attention must be paid to both the methods of ultimate disposal available and the solids content required. A potentially costly situation which should be avoided is for the dewatering process to remove more water than necessary for the selected available technique. Table 2-16 represents the compatibility of the principle ultimate disposal techniques with principle methods of mechanical dewatering.

l_--__-l___Environmental Issues Environmental factors re1 ated specifically to the dewatering process incl ude :

0 Energy requirements

0 Noise

0 Vibration

@ Odor potential

0 Aesthetics (visual impact)

e Ground water contamination.

An evaluation of these environmental considerations is presented in Table 2-17.

Energy Requirements. There are several variables which affect the dewatering energy .---l_--l__ requirements :

0 Quality of sludge; generally, as the ratio of the primary to the secondary secondary sl udge decreases, the energy requirement increases.

Sol ids concentration of sludge feed.

0 Conditioning method selected.

2-34 DEWATERED SLUOCE CAKE. PERCENT TOTAL SOLIDS

IO 20

70% Pt 30% WAS

F.YI 50% Pa 50% WAS , , , D.F.P.

30% Pa 70% WAS

0% Pa 100% WAS

LEOEND CENT. -SOLID BOW1 XNTRIFUGE 8. CENT. -BASKET CENTRIFUGE V.F. -VACUUM FILTER F.P. -FILTER PRESS 8.P. -8ELT PRESS D.F.P. -DIAPHRAGM FILTER PRESS

Figure 2-13. Dewatered Sludge Cake Percent Solids for Mixtures of Digested Primary (PI) and Digested Waste Activated Sludge (WAS)'

Source: Ref. 11

2-35 DEWATEREDSLUDGE CAKE, PERCENT TOTAL SOLIDS

c-- I V.F. c ---q1 Raw Primary I D.F.P. I B.CENT. 1 S6L

D.C.C.

c :ENT. I I V.F.

Raw Was F,pliD.F.P. t- e a --I --I

LEGEND

Figure 2-14. Dewatered Sludge Cake Percent Solids for Raw Primary and Raw WAS

Source: Ref. 11

2-36 Table 2-12

TYPICAL SOLIDS CAPTURE OF DEWATERING PROCESSES

Typical Sol ids Capture Process ---- % ---- Basket centrifuge 80 - 98 Sol id bowl centrifuge 90 - 98 Belt filter press 85 - 95 Vacuum filter 88 - 95 Filter press 98 -- Note: Sol ids capture percentages shown are for properly operated dewatering system with well conditioned sludge.

Source: Ref. 11

Table 2-13

CHEMICAL CONDITIONERS USED FOR DIFFERENT DEWATERING PROCESSES

Ferric Process --Lime* ----Chloride Polymer Basket centrifuge C Sol id bowl centrifuge C Bel t fi 1 ter press C Vacuum filter C C C Filter press C C P

LEGEND:

C - Common usage P - Possible; used in certain situations, but usage is not common * Lime and ferric chloride are typically used together

Source: Ref. 11

2-37 Table 2-14

TYPICAL DOSAGES OF CHEMICAL CONDITIONfRS FOR DIFFERENT DEWATERING PROCESSES

Raw Anaerobically Primary & WAS Primary & WAS 91kg 91kg -P roc e s s/ C hem ic a 1 (1b/ton) (1b/ton) Basket Centrifuge Po ymer 0-2 0.5 - 2.5 1-3 (0-4) (1-5) (2-6 1 Sol id Bowl Centrifuge Po ymer 1 - 2.5 2-5 3-5 (2-5) (4-10) (6-10)

Belt Filter Press Polymer 2-4 2-5 4 - 7.5 (4-8) (4-10) (8-15)

Vacuum Fil er Polymer 5 2-5 3-6 (4-10) (6-12)

~ime3 80 - 100 90 - 160 150 - 210 (160-200) ( 180- 320) (300-420)

Ferric Chloride3 20 - 40 25 - 60 30 - 60 (40-80) (50-120) (60-120)

Filter ress Limes 110 - 140 110 - 160 110 - 300 (80-120) (80-140) (80-200) Ferric Chloride3 40 - 60 40 - 70 40 - 100 (80-120) (80-140) (80-200)

1. These typical dosages correspond to the typcial recoveries shown in Table 4- 1. Poiymer requirements are for dry polymer, and lime requirements are for lime as CaO.

2. Polymer can sometimes be substituted for lime and ferric chloride in conditioning raw sludges for vacuum filtration.

3. Lime and ferric chloride are typically used together at these dosages.

Source: Ref. 11

2-38 Table 2-15

COMPATIBILITY OF DEWATERING EQUIPMENT WITH PLANT SIZE

0.04 cu m/s 0.04-0.44 cu m/s 0.44 cu m/s ( 1 MGD) 1 - 10 MGD) ( 10 MGD)

Basket Centri f uge X X

Sol id Bowl Centrifuge X X

Belt Fi1 ter Press X1 X

Vacuum Fi 1 ter X

Filter Press X

Drying Beds X X

S1 udge Lagoons X X

1 Only low pressure presses are commonly used in this range.

Source: Ref. 11

2-39 Table 2-16

DEWATER ING PROCESS COMPATIBILITY WITH SUBSEQUENT TREATMENT OR ULTIMATE DISPOSAL TECHNIQUES

Dewatering Process Incineration1 Composting Application Landfi 11 . ~~

Basket Centrifuge X X

Sol id Bowl Centrifuge X x3 X X ,. Belt Fi1 ter Press X X X

Vacuum Filter X x j x4 X

Filter Press X X x4 X

1. The' sol ids content required for self-sustaining combustion will vary depending upon the percent of solids that are organic and the caloric value of the organics . 2. Some states and municipalities have rigid requirements on the solids content of sludges placed in landfills. Local regulations should be checked by the designer.

3. Suitability of this method depends on the organic content of the sludge. The thermodynamics of composting must be evaluated. Generally, sludges with a 20% or greater solids content can be composted, depending on the degree of prior stabilization and the weather conditions.

4. Soil characteristics are important. For some alkaline soils (i.e., some calcareous soils) land application may not be desirable because of lime in the dewatered sludge cake. For soils with a high sodium content, however, addition of calcium can beneficially increase the calcium/sodium ratio and result in improved tilth. There are very few solids where a problem would be anticipated due to application of sludge cake. Advice of agriculturalists is recommended.

2-40 Table 2-17

EVALUATION OF ENVIRONMENTAL CONSIDERATIONS OF DEWATERING PROCESSES

ENVXROWENTAL CONCERN Potential For Energy Odor Visual Ground- t et Process Requirement Noise Vibration Potential* Impact Contamination

Basket Centrifuge High Moderate High Low None None Solid Bowl Centrifuge Moderate to High Moderate to High High Low None None b+ Belt Filter Press Low Low Low Moderate None None Vacuum Filter Moderate to High Moderate Low Moderate None None Filter Press Moderate to High Mode r a t e Low Moderate None None Drying Beds Lo No ne *** None High High High Sludge Lagoons Lo** None *** None High High High

*Rating is based on dewatering a poorly stabilized sludge. If sludge is well stabilized, there should be no significant odor from any dewatering process,.

**Energy required is electricity for sludge pumping and diesel fuel for equipment used to remove dewateredldried sludge.

**Noise levels for drying beds and lagoons can be high during cleaning due to heavy equipment and "beep-type" signaling device required when operating in reverse. 0 Number of machines; more energy is generally required to run two smaller machines than one large machine of an equivalent capacity (except for sol id bowl centrifuges).

0 Solid throughput achieved.

Table 2-18 presents the ranges of electricity and fuel requirements for dewatering.

Indirect energy requirements for sludge dewatering are shown in Table 2-19 and Figure 2-15.

Thermal Conditioning

Thermal conditioning (heat treatment) is a1 so frequently employed to condition sludge in an effort to improve dewatering. Energy requirements differ between low- oxidation systems (thermal treatment systems which employ air) and nonoxidation thermal conditioning systems, which do not have suplemental air. The electricity requirements vary between the two types of system and are shown on Figure 2-16, assuming a fired solids concentration of 4 to 5%. Fuel requirements for heat treatment without air addition range from 900 to 1000 Btu/gal of sludge processed. Fuel requirements for heat treatment with air addition are lower, ranging from 300 to 600 Btu/gal since combustion supplies a portion of the heating requirements. Heat treatment is most applicable in conjunction with incineration systems that employ waste heat recovery, where energy can be recovered as medium-pressure steam for use in the thermal conditioning process.

Incineration

Incineration is the process of burning the volatile materials in sludge solids in the presence of oxygen. Incineration converts sludge into an ash which can then be either disposed of or reused. However, as a result of the drastic reduction in volume and mass of residual solid materials, incineration has traditionally been regarded as a disposal method and is evaluated in comparison with land application, sale as fertilizer; landfilling; and ocean disposal as a use/disposal option. Incineration is a proven sludge disposal technique and is currently used on 25% of the nation's wastewater sludge. Table 2-20 lists the heating values for several sludge materials and various fuels. Dry raw sludge solids are typically comparable in fuel value to low grade coal, wood, and municipal refuse.

In order to burn without auxiliary fuel , sludge usually must contain 25 to 35% solids, a level that is achievable with some sludges through conventional mechanical dewatering. To achieve the proper mix for the most efficient burning, conventional

2-42 Table 2-18

GENERAL RANGES OF DIRECT ENERGY REQUIREMENTS FOR SLUDGE DEW ATE RING^

Tot ai Equivalent

Fuel __ ,_ Electricity Electricity2 Process kJ/kg dry kwh7kg dry wdry sol ids __-( kwh/ t on) -___solids ---(kuh/ton)

Bosket Centrifuge 0.105-0.140 (90-120) 0.105-0.140 (90-120)

Solid Bowl Cent r ifuge

Lows peed 0.035-0 .O 70 ( 10-60) 0.035-0.070 ( 10-60)

High-speed 0.070-0.105 (60-90) 0.070-0.105 (60-90)

Belt Filter Press 0 .O 1 1-0.029 ( 10-25 1 0.01 1-0.029 ( 10-25)

Vacuum Filter 0.046-0.070 (40-60) 0.046-0.070 (40-60)

Fixed Volume Pi1 t er Pres s 0.046-0.070 (40-60) 0.046-0,070 (40-60)

Diaphragm Filter Press ------0.04 1-0 .064 35-5 5) 0.041-0.064 (35-55)

Drying Bedl 23 (20.000) 0.001-0.002 (1-2) 0 .OOl-0.004 (3-4)

Sludge Lagoons 102 - 170 (88,000-146,000) 0 .oo 1-0.002 (1-2) 0.010-0.018 (9-16)

'For dewatering digested 50:50 mixture of primary and WAS at 3 percent feed rolida.

zPuel converted to equivalent electricity using a factor of 11.080 tJ per kth (10,100 BTlJ/kuh) and an electrical generation efficiency of 32.5X.

Source: Ref. 11

2-43 Table 2-19

INDIRECT ENERGY REQUIREMENTS FOR SLUDGE DEWATERING*

Indi rec t Electrical Energy Dewater ing Conditioning Chemical Dosage kwh/ kg kwh/ ton Process Chemic a1 g/kg ( 1 b/ ton) -dry sol dry sol Basket Centrifuge Polymer 3 (6) 0.0007 (0.6)

Sol id Bowl Centrifuge Polymer 4 (8) 0.009 (0.8)

Belt Fi1 ter Polymer 6 (12) 0.0013 (1.2)

Vacuum Fi 1 ter Lime 150 (300) 0.099 (90.0) FeCl3 40 (80) 0.044 (40.0)

Filter Press Lime 120 (240) 0.079 (72.0) FeCl3 50 (100) 0.055 ( 50.0)

* Sludge type is digested primer t WAS.

Source: Ref. 11

2-44 200 INDIRECT ENERGY .22 -

180 DIRECT ENERGY .20 - nU T NPICAL RANGE FOR 160 .18 - DIRECT ENERGY I

.16 - 140

.14

.12

nJ .10 I P m .08

.06 T

.04

0 BASKET LOW SPEED HIGH SPEED BELT VACUUM FIXED DIAPHRAGM DRYING CENTRIFUGE SOLID BOWL SOUD BOWL FILTER FILTER OLUME FILTER BEDS CENTRIFUGE CENTRIFUGE PRESS :ILTER PRESS VESS

Figure 2-15. Direct and Indirect Energy Requirements for Sl udge Dewatering Processes 34

26 24

12 10

8 6

4 2 a 1 10 100 1,000

Figure 2-16. Electrical Energy Requirements for Thermal Conditioning (Not incl udi ng the fuel requi rements)

Source: Ref. 6

2 -46 Table 2-20

TYPICAL ENERGY VALUES FOR SEVERAL SLUDGE MATERIALS AND VARIOUS FUELS

Energy Value Combustible % of KJI kg Btullb Materials The Dry Solids Dry sol ids Dryolids

S1 udge

Grease and scum 88.5 38,410 16,700 Raw sludge solids 74.0 23,655 10,285 Digested sl udge 59.6 12,167 5,290

-- -I_ ----- Fuel s No. 2 oil - 45,080 19,600 No. 6 oil - 40,250 17,500 Natural gas - 52,440 22,800 Bituminous coal - 31,280 13,600 Wood (ai r-dried) - 12,650 5,500 Refuse-derived fuel - 17,250 7,500

- Source: Ref. 5

2-47 sludge incineration systems use 20 to 150% excess air because it is virtually impossible to ensure complete and even mixing of air and sludge. The amount of excess air required is not only dependent on the type of system chosen, but also on the operating procedures. Decreasing the excess airflow will result in reduction of auxiliary fuel usage; nearly all the auxiliary fuel burned in the incineration process is used in the evaporation of water from the sludge.

Many types of incinerators have been developed, but multiple hearth and fluidized- bed furnaces are the most widely used in the United States (Figure 2-17).

Multiple hearth furnaces consist of a vertical incineration cylinder with multiple horizontal cross-sectional floors where waste cascades from the top floor to the next and so on, steadily moving downwards as the wastes are burned.

Fuel usage is generally the primary operating cost of an incineration system. The amount needed depends on the water content of the sludge, the efficiency of the particular system, volatile solids content, and operator skill. Energy is required in each step of the incineration process:

0 Sludge dewatering prior to incineration,

0 auxiliary fuel during incineration, and

0 heating of incineration air prior to use.

The energy requirement for a mu1 ti pl e-hearth furnace with 780°C (1400°F) exhaust burners, 150% excess air, and 24% sol id feed sl udge is 0.088 kWh/kg of dry sol ids (0 040 kWh/lb) for electricity and 14,030 KJ/kg (6,100 Btu/lb) for fuel.

------Anaerobi c Digestion Anaerobic digestion is a two-stage process in which organic materials are decomposed biologically in an oxygen-deficient environment and thereby transformed into methane and carbon dioxide (approximately 2/3 methane and 1/3 carbon dioxide). The methane gas produced is used as fuel for sludge heaters. There are two basic configurations of conventional anerobic digesters: single stage digestion and two-stage digestion as shown on Figure 2-18.

The energy requirements for the process vary with the time elapsed, percent water in the sludge, and air-to-solids mixing ratio. For example, with a solids retention time of 15 days, a 6% dry solid feed sludge, and mixing based on 1/2 hp/28 m3 Of digestor volume, 4.4 kWh/kg of dry solids, (2 kWh/lb) of electricity will be required to complete anaerobic digestion. 2-48 Multiple-HearthFacilities \ 81 % (1 50)

Figure 2-17. Relative Prevalence of S1 udge Combustion Facilities Operating in the U.S.

Source: Ref. 5

Mixing Mixing CH, C02 CH, C02

Influent Stabilized Supernatant

Thickened Stabilized Product

SINGLESTAGE CONVENTIONAL DIGESTER TWO-STAGE CONVENTIONAL DIGESTER

Figure 2-18. Schematic Diagram of Conventional Anaerobic Digestors

Source: Ref. 6

2-49 Table 2-21

ENERGY REQUIREMENTS FOR SLUDGE STABILIZATION

Electr ic ty Fuel Total Energy Process kwh/lb( 1 ) Btu/lb Btu/l b -I-____-__ ---- Aerobic Digestion' 0.240 -- 9300 Composting3 -- 23 23 Forced Aeration Static Pile 0.002 23 48

1. Lbs of dry solids.

2. Solid retention time: 16 days, mechanical aeration based on 1.5-lb 02 transfer/ hp- hr

3. Feed solids: 25% dr weight solids, forced aeration, 1/3 hp blower for pile with 50 ydY sludge

_- Source: Ref. 6

2-50 Sludge Stabilization Alternatives ~---_I_- I- Table 2-21 presents the energy requirements for some of the other sludge sta- bili zation a1 ternatives.

Advanced Wastewater Treatment Processes - -I------At the present time, advanced wastewater treatment (AWT) processes represent a very small fraction of the total energy consumption by POTWs; however, this trend is expected to change in the future in order to meet more stringent discharge requirements. Table 2-22 lists AWTs according to constituent conversion, removal, or control to achieve the particular water quality requirements. The following treatment processes are discussed in detail in the hazardous industrial wastes section of this report: filtration, ozone oxidation, reverse osmosis, electrodialysis, ion exchange, and freeze concentration -- which could be used for removal of suspended solids as well as total dissolved solids (TDS). In this section the nitrification process will be discussed because of its major potential for future contribution to total energy consumption by POTWs.

Nitrification. This is a biological process for oxidizing ammonia and organic nitrogen to nitrate form. Nitrification is utilized to control the organic nitrogen content of the discharge stream. The purposes of the process are to reduce the BOD on the receiving stream as well as regulating the level of ammonia in the discharge. The stoichiometric relationship for nitrification is as follows:

NH4 + 1.7 02 + 0.0318 HCOj + 0.127 CO2 -- 7 ( ammon ia) (oxygen) (alkalinity) (carbon dioxide)

0.0318 CSH702N t 0.968 NO3 t 0.953 H20 t 1.94Ht (bacteria1 cell) (nitrate) (water) (hydrogen ion)

Because nitirfication rates are optimum at a pH in the range 7.2 to 8.4, it is often necessary to add alkalinity (lime) to maintain neutral conditions.

The basic operational parameter governing nitrification in suspended growth systems is the solids retention time (SRT). The SRT must be sufficiently long to permit growth of specific microorganisms which oxidize ammonia and nitrite to nitrate. Schematic diagrams of single-stage and two-stage biological nitrification are shown in Figure 2-19. The energy requirements for single-stage nitrification is ill ustrated in Figure 2-20.

2-51 Table 2-22

ADVANCED TR EATME NT PROCESS ES

Constituents removed or controlled Treatment process

Nitrogen control Nitrification, single stage Nitrification, two stage Denitrification, suspended growth Denitrification, attached growth Ammonia stripping Selective ion exchange Regenerant recovery (ARRP) Breakpoint chlorination Phosphorus Alum addition Ferric chloride addition Lime addition, primary Lime addition, tertiary Recalcination PhoStrip (Lotepro) A/O (Air Products) Nitrogen and phosphorus A2 /O (Air Products) Bardenpho (Envirotech) Suspended solids Microscreens Filtration Refractory organics Granular activated carbon Powdered activated carbon Carbon regeneration Multiple-hearth furnace Fluidized bed furnace Wet air oxidation Ozone oxidation Air stripping TDS Reverse osmosis Electrodialysis Ion exchange Cationlanion exchanger Strong acid/sodium exchanger PH Sulfuric acid addition Sodium hydroxide addition Lime addition Recarbonat ion Disinfection Chlorine Ozone Chlorine dioxide Ultraviolet radiation Dechlorination Sulfur dioxide Activated carbon summary

Source: Ref. 6

2-52 Feed- Pump Lime Slaker & Storage I

Influent Basin Nitrified Effluent Nitrification

Figure 2-19 (a). One-stage Suspended Growth Nitrification

Lime Slaker & Storage

Secondary Effiuent Aeration Sedimen- Basin 4. c tation b Nitrified Effluent Nitrification

I Retum Nitrified Sludge Waste 1 Sludge

Figure 2-19 (b). Two-stage Suspended Growth Nitrification

Source Ref. 6

2-53 Fig. 2-20. Specific Energy Requirements for Suspended Growth Nitrification (One-stage)

(NH3N) Oxidized mg/L Source: Ref. 6

2-54 Methods of Disposal for Municipal Sludges

Table 2-23 lists the various methods described above for municipal sludge disposal based on percentage of their use.

2-55 I Table 2-23

DISPOSAL METHODS FOR MUNICIPAL SLUDGES

Met hod Percentage Use

Land application 29 Incinerati on 25 Landfi 11 21 Distribution and Marketing 21 Ocean Disposal 4

Source:' Ref. 5

2-56 REFERENCES

1. "Basic Data in Sol id Waste hounts, Composition and Management Systems." National Solid Wastes Management Association, Technical Bulletin, #85-6, October 1985.

2. "Sol id Waste Data." JRB Associates Report. McLean, Virginia: 1981.

3. Waste Age Magazine, Various issues 1984 - 1986.

4. "United States Conference of Mayors Survey of Resource Recovery P1 ants." World Waste Magazine, 1985.

5. U.S. Environmental Protection Agency. "Use and Disposal of Municipal Waste Water S1 udge." EPA-625/10-84-0003, reptember 1984.

6. F.W. Owen. "Energy in Wastewater Treatment." Prentice-Hall Inc., 1982.

7. W.H. Flusch and H. Perchthaler. "Separation of Oil and Water from 011 Refinery S1 udge." Fi 1 tration and Separation, September/October 1982.

8. W.R. Lecey and A.K. Pietila. "Improving Bel t-Fil ter-Press Performance." Chemical Engineering, November 28, 1983.

9. G.L. Culp. Handbook of Sludge Handling Processes. New York & London: Gerland STPM Press, 1979.

10. L. Saurovsky. "Fi 1 tration and Allied Operations." Chemical Engineering. July 2, 1979.

11. U.S. Environmental Protection Agency. "Process Design Manual for Dewatering

Municipal Waste Water S1 udges .'I EPA-625/1-82-014, October 1982.

12. L.C. Tsaros. "Peat Dewatering, an Overview." Arlington, VA: Conference on Peat as an Energy Alternative, December 1981.

2-57

Section 3

NON- HAZARDOUS IND US TR I AL WASTES

The current annual generation rate of industrial non-hazardous waste in the United States is approximately 393 million metric tons. Table 3-1 lists the quantities of non-hazardous wastes generated by individual industry segments , whi 1 e Table 3-2 presents the relative ranking of industries based on sludge generation rates, The Industrial Organic Chemicals industry (SIC 2819) has the highest generation rate and accounts for 25% of the industrial non-hazardous wastes produced. The top 12 waste- producing industries generate about 99% of a1 1 industrial non-hazardous wastes.

MANAGEMENT TECHNOLOGIES FOR NON-HAZARDOUS INDUSTRIAL WASTES

There is more information available on types and amounts of industrial non-hazardous wastes than on either management technologies for on-site treatment of the wastes or the quantities of waste associated with each type of management technology. The primary management technologies are the following:

0 On-Site surface impoundment

0 On-site landfill

0 On-si te "temporary" stock pi 1 ing

0 Off-site landfills

Tab1 e 3-3 represents a summary of industrial non-hazardous waste generation and man ag em en t .

A significant amount of non-hazardous industrial waste is disposed of in landfills, at least 145 million metric tons annually in on-site landfills and surface impoundments, accounting for approximately 35% of the total annual domestic production of non-hazardous industrial waste. The estimated quantity of non-hazardous waste being stored in on-site waste stockpiles is 79 million metric tons; therefore, the total amount of waste being managed annually on-site by land disposal methods is 224 million metric tons, or 57% of all industrial non-hazardous waste generated annually. The remaining 43% of the non-hazardous waste is sent off-site for disposal. Table 3-4 i11 ustrates the avai 1 ab1 e data on non-hazardous waste management methods in the indu s t ry .

3-1 Table 3-1

LISTING OF INDUSTRIES BY ESTIMATED ANNUAL AMOUNTS OF NON-HAZARDOUS WASTE GENERATED

Waste Quantity Percent of Indus try (Dry Metric Tons) Total

Industrial Organic Chemicals (SIC 2819)

Primary Iron and Steel Manufacturing and 60,679,0002 15.5 Ferrous Foundries (SIC 3312-3325)

Fertilizer and Other Agricultural Chemicals 59,037,400L 15.0 (SIC 2873-2879)

Electric Power Generation (SIC 4911) 55,878,0002 14.2

Plastics and Resins Manufacturing (SIC 2821) 44,991,7002 ’ 11.5

Industrial Inorganic Chemicals Industry 26,191,8002 6.7 (SIC 2812-2819)

Stone, Clay, Glass, and Concrete Products >18,600,000 4.7 (SIC 32)

Pulp and Paper Industry (SIC 26) 8,627,0005 2.2 Primary Non-Ferrous Metals Manufacturing and 6,575,0002 1.7 Non-Ferrous Foundries (SIC 3330-3399)

Food and Kindred Products (SIC 20) 6,361,5006 1.6

Water Treatment (SIC 4941) 4,960,000 1.3

Petroleum Refining Industry (SIC 29) 1,276,400 0.3 Rubber and Miscellaneous Plastic Products (SIC 30) 542,6002 0.1

Transportation Equipment (SIC 37) 520,000 0.13

Fabricated Metal Products (SIC 34) 300,000 0.08 Pharmaceutical Preparations (SIC 2834) 256,900 0.07

Machinery, Except Electrical (SIC 35) >193,5007 0.05

Lumber and Vood and Furniture and Fixtures > 122,7002 l8 0.03 (SIC 24 and 25)

Textile Manufactuting (SIC 22) >45,000 0.01

3-2 Tab1 e 3-1 (continued)

Waste Quantity Percent of Industry (Dry Metric Tons) Total

Soaps; Other Detergents; Polishing, Cleaning, 31,3002 0.01 and Sanitation Goods (SIC 2841-2842) Leather and Leather Products 24,600 0.01 Electrical Machinery and Electronic Components 10,4009 >0.01 (SIC 36) Total >392,579,900

- 'Estimates do not include wastes that are discharged to publicly-owned treatment works (POTW) or recycled unless they are sometimes stored or treated in waste piles or surface impoundments prior to recycling.

'Dry or wet weight not specified; assume wet weight. 336,164,800 when aqueous wastes are not counted. 4a,643,400 when aqueous wastes are not counted. 56,081,000 when aqueous wastes are not counted. %et weight . 71ncludes only wastes from SIC 355 and 357 (representing 12 percent of total sales). 8The total amount of wastes in this industry is large, however, most of the wastes are recycled; no quantities on total waste generation are available.. The quantity shown above may include significant quantities of hazardous waste. 'Data on waste types and amounts were available only for SIC 367 (represents only 2 percent of total value of 1976 product shipments from the industry).

Source: Ref. 1

3-3 Table 3-2

SLUDGES GENERATED AS A RESULT OF POLLUTION CONTROL RATES FOR SELECTED MANUFACTURING INDUSTRIES

Air and Water Pollution Control Sludges Industry SIC (Metric Tons/Year) Electric Power Generation * 4911 * 60,000,000 * Stone, Glass, and Clay 32 >15,330,000 Primary Metals 33 8,822,000 Chemicals 28 8,094,000 Pulp and Paper 26 7,865,000

Petroleum 29 4,670,000 Food and Kindred Products 20 4,330,000

Lumber and Wood Products 24 >941,000 Machinery (except electrical) 35 >339,000

Transportation Equipment 37 336,000 Wood Furniture and Fixtures 25 > 3 13,000

Electrical Equipment 36 237,000

Rubber and Plastics 30 193,000 Fabricated and Metal Products 34 > 170,000

Text i les 22 138,000 Instruments and Related Products 38 ND Miscellaneous Manufacturing Indus tries 39 ND

NO = No comprehensive data were found. * Estimated generation rates for fly ash and bottom ash combined. Source: JRB Associates 1983. Ref. 2

3-4 Table 3-3 SUMMARY OF INDUSTRIAL NON-HAZARDOUS WASTE GENERATION AND MANAGEMENT

Amount of Waste Number of On-Site Percent of Nun-Hazarduus Wastes Managed' b Gene r aced Non-Hazardous Disposal Facilities On-S i ce Of f-Si te ndustry Waste Typea (Dry Hetric TonsfYr) LF SI LT Other Total LF SI LT Other Total Disposal Ocher

Fer t i I i zer 59,037,400 __ -_ -. and Other Agricultural Waste gypsum 39,075,0007 Chm ical s (SIC 2873- Wet scrubber 678,10O1l 2879) I iquor

Cooling water >500,00011 treatment sludgs WPPA sludge __

Spenr catalyst ._

SUI fur fi iter __ cakes ' I __ W Pest icide manu- 18,784,3006' <.I 46 0 23 70 8 69 I facruring wahres Ln

Food and 6,361,500'~,~~ -. 4,960~ -- ______K L idr2.d Producrs Paunch manure 772,600~~~ 20 2.2 15.6 80 80 (SLC 20) Meat sludge 347,00014 __ _- H -- __

Liquid whey 373, 20-25 0 10-15 75-80 75-80

Unusable fuod I ,493,00014'15 10-15 -- 10-15 __ M

Sail and crash 229,50014 ______Y

Nan-food wabte 386,OOOI4 10-15 -- -_ Y

Grain mill sludge 55,900~~'~~ ______

Sail I,IOO,OOO~~ IO0 0 0 0 ( augar prod. )

Lime mud (sugar I ,100,00014 100 0 LOO 0 0 0 0 0 prodllcr,)

Excess bagasse 242,60014'15 IO0 100

Spsnr bleaching 55,30016 __ __ .. 11 I t, .cm

m- .um- I.0 u (00 VI n Yu. m MU.- moa 4 r- fn u uc00 d 34

m I m -a n rcI I-

3-6 h

3-7 Table 3-3 (continued)

Amount of Waste Number of On-Site Percent of Non-Hazardous Wastes Managed‘ b Generated Non-Hazardous Disposal Facilities On-S i te Off-Site Indusr ry Waste Typea (Dry Metric TonslYr) LF SI LT Other Total LF SI LT Other Total Disposal Other

katlirr and 24,600~‘9 __ l.?at her Pr uduc r s Trimmings and 7,60OzB9 (SIC 31) shav i ngs

Unfinished 1,4002’9 leather trim

Buffing dust 4002’9

Finished leather trim

Finishing residues 700’ *9 W I Wastewater screenings 1 ,300299 a3 Wastewater sludge 4,2002’9

Miscellaneous solid 6,3002’9 wastes 11, ,I I I 11, II I I

Ill IN I Ill IN I ,I

011 IN I I Ill IN I I

I..-1

c h -a YIo Ill IW I I W c0 Ill Ih I I 3 S n '7 c, S 0 V v 0

mI W

C z0 I .l0;

0 N0

N N

u mII

m Wc m DM u 0a ch a u

3-9 Table 3-3 (continued)

Amount of Waste Number of On-Site Percent of Non-Hazardous Wastes Managed' b Generated Non-Hazardous Disposal Facilities On-Site Of f-Site Industry Waste Typea (Dry Metric TonsIYr) LF SI LT Other Total LF SI LT Other Total Disposal Other

Pe 1 ro I eum Non- leaded tank 131 ,6OOL3 52 0 0 52 0 48 48 0 Ke F i ning bottoms Industry (continued) Primary O/S/W 71,600' 31 0 0 31 0 63 63 0 separator SI udge

Stretford solution 0 0 0 100 100 0

IIF alkylation sludge 26 13 37 74 37 0

Spent catalysts 15 0 15 85 85 0

Cooling tower 60 0 60 40 40 0 SI udge

21 0 w Treating clays 0 21 0 19 19 0 I w Secondary O/S/W 44 0 0 44 0 56 56 0 0 separator sludge

Pharmaceutical 256,90025 -- __ -- ______0 0 __ -- 90 __ Industry (SIC 2831 Biological sludge 82,600' -2834) Fi Iter aid: carbon 78,400'~ sawdust, mycel I ium

Wet plant 2,000~~ material

Fused plant 80O25 steroid ingots

Ex t r acten an imal 7,500~~ tissue

!I I I ii I Table 3-3 (continued)

Amount of Waste Number of On-Site Percent of Nan-Hazardous Wastes Managed‘ Cener a t ed Nan-Hazardous Disposal Facilitiesb On-Site Off-Site Indubr ry Waste Typea (Dry Metric Tons/Yr) LF SI LT Other Total LF SI LT Other Total Di-sposal Other

Pharmairur ical Glass, paper, vuud 75,0006’25 0 0 __ ._ 100 -_ Przparar ~unc aluminum, and (iunt inlied) rubber scrap __ Plastics~. and 44,991,7006’12’26 63 235 II 69 0.8 68 0.1 58 79 1.3 78 Resins

Hanu fact ur i ng Decan tatPSI 7,265 ~ I 006 ’ ’26 NR 34.8 NR 91.5 -- 1.7 52.3 (SIC 2821) filtrates

Sludges 434,9006 ’ ’26 -_ 81.6 5.1 6.4 2 __ 4.4 1.5

Of f-spec . 29 3,8006” 2’26 __ 1.7 9.1 NR 16.6 -- 8.3 0.57 prvduc t s

Spent so I ven t s 286,6006”2 ’26 __ NR <0.1 NR 99.5 --

Light ends 195,7006’12’26 -- NR c0.I NR 74.4 -- NR 32.8

Yiscellaneuus 121 ,6006’12326 -_ 2.3 NR NR 79.0 -- 84.7 2.4 sul ids

Prrcipiratiunl 31 ,0006’12’26 __ 21.5 28.4 NR 33.3 -- 39.8 27.6 filtration residues

Heavy ends 16, 3006’ ’ 26 __ NR 3.4 NR 89.9 -- 4 :3 11.6

Process waste 30,936,2006’12’26 -_ NR 80.9 <0.1 41.5 -- 0.4 83.6 watec

Equ 1 pmenc vashdom 258,9006 ’ ’26 _- NR 92.2 NR 1.6 -- NR 100

Steamje t 117,6006’12’26 __ NR NR NR IO0 -_ NR 100 condensate

Spent scrubber 2,354,5006 ’I ’ 26 __ NR 0.2 NR 65.8 -- 1.7 IO0 vater

Nunprocess 2,679,5006’12’26 -_ NR 89 NR 89.1 -- NR 90.2 vabtevatrr l a 001 , ,I II I 4 to- 4 I IO II I, I I ,I

0 I , I 0,, I ,I 11 I I I 10- I 1010 I! ,I , I I N VI 5: aNIX cz VI VI m -aa -0 4 0- 0 a- 0 0 u-0 y\ IO IO, v)-0 0 2 00 I.0 I I- D-!

I I, ,I ! 100 I IO0 I I 41 1 ! ,

z z z a a a -1 -1 J IN *I , ,I 4 I I NO0 t - 00 NI I ,I I I

m I 0

el.- h ------Q QQ Q Q- Q Q Q QQQ Q 0 00 00 0 00 0 0 0 000 0 0 c0 00 0 00 0 0 0 0 0 0 0 0 0- 0- 0" 0- 0- 0- 0- 0 0 0 000 0 "-- I Q am Q- < mu- J 0 ~NNc o QO N- 00 0 c mu- - 01 0-" - Q N W M - U al M 33 - .-Y ...- s- 3s a E mM '3 - cc?M x u s mal ii -u 1GI ioM io1 C .E ; --mm mn ,.. Y cn -9 -3so w4 Ca uv'3m czu5.c U0 mio v1 asLV

3-12 Table 3-3 (continued)

Amount of Waste Number of On-Site Percent of Won-Hazardous Wastes Hanagtld‘ b Generated Non-Hazardous Disposal Facilities On-Site Off-Site [ndus! ry Waste Typea (Dry Hetric TonslYr) LF SI LT Other Total LF SI LT Other Total Disposal Other

Primary Iran Pickle liquor -- and Steel SI udge nanufacturing and Ferrous Galvanizing 40 ,?go6 Foundr i es sludge ( cont i nued) Tin plaring 1 6,0006’ sludge

Bricks and 7,374,0006’7 rubble

Fly ash and w bottom ash I w W Foundry sand 14,417,0006” and other wastes

Pr imary 30 Non-Ferrous t4t.r a I s Primary aluninum Uanu fact ur i ng wastes and Non- Ferrous Primary copper Foundr ies wastes (SIC 3330- 3399) Primary zinc wasres

Primary lead wastes

Foundry sand and other wastes ,I

E W0 ,I

I ,

I ,I I

I ,8 ,I

,1 I ,I

0 0N 0 I

I I tI

0 0 9 0. I W UN N-f -

VI uffl

VI ._I m W u W uVI m ffl M c" ; u ... 1 cffl W u ... WM u .-C m '3 uv 4 Y 3m m n. zRI Ln0- ,n

x YL

3-14 Table 3-3 (continued)

a. Waste types from more than one product or process within an industry often are combined under one listing in this table. Such combining often prevented the listing of waste management information for a given waste. This information is available in Section 4 of this report. b. LF = landfill; SI = surface impoundment; LT = land treatment c. Numbers in all colmns represent the percentage of total wastes; note the sum of numbers in one row may exceed 100 percent if one management method is used prior tu another method for the same waste stream. Also note: The management data represent the same year as the quantity data, unless otherwise indicated. I. Data on waste types and amounts were available only for SIC 367 (represents only 2 percent of total value of 1976 product shipments for the industry) 2. 1975 data

3. ~~-_1~=data nut available 4. Daca from the "Surface Impoundment Assessment National Report" were collected in 1978-1980. EPA 570/9-84-002. Office of Drinking Water, December, 1983. 5. ti = must of the referenced wastes are managed by this technology; however, no percentage values are available in the literature. 6. Dry or wet weight not specified; assume wet weight. 7. 1983 data 8. Data on nun-hazardous waste streams in this industry are almost completely non-existent. The list of waste types is incomplete. 9. Includes hazardous and nun-hazardous wastes, depending on the source. IO. Electroplating and metal finishing only; other SIC 34 groups unknown; 1979 data. 11. 1980 data 12. Estimated from the Industry Studies Data Base, compiled for the USEPA by SAIC. 13. 1981 data W I 14. 1976 data mw IS. Wet weight 16,. 1984 data 17. 1979 data 18. LUN = location of the management site (i.e.. on-site or off-site) is unknown. 19. Includes the entire chemical manufacturing industry (SIC 28). 20. NR = Nut reported by any industries surveyed to compile the Industry Studies Data Base. See footnote number 12 above. 21. The total amount of wastes within this industry is large; however, most of the wastes are recycled; no quantities on total waste generation are available. 22. Lncludes only wastes from SIC 355 and 357 (representing 12 percent of total sales in SIC 35); 1977 data. 23. 1977 data 24. Landfilling is the prominent off-site disposal method for petroleum wastes 25. 1973 data 26. 1982 data 27. Includes the primary non-ferrous metals industry. 28. R = This waste is stockpiled prior to recycling 29. S = Stockpiled 30. The number of waste streams in this category were too numerous to include in the table. See Section 4.16 for more detail. 31. Includes the primary iron and steel industry. 32. This estimate is known tu exclude significant quantities of non-hazardous wastes. 33. SIC = significant quantities are believed to be generated. 34. Disposal methods are the subject of an ongoing survey.

Source: Ref. 1

li I Table 3-4 EXISTING QUANTITATIVE DATA ON INDUSTRIAL MANAGEMENT OF NON-HAZARDOUS WASTES

Quantities of Non-Hazardous Wastes Managed (Dry Metric Tons)a -__-- -___- -- -- On-Site of f-Site Sur face Land Land 1 Ind us try Land fill Impoundment Applications Other Disposal Other

Electric Power Generation (SIC 4911) N/A~ 28,497,800~ N/A N/A N/A N/A

Fer t il i zer and Other Agricultural Chemicals (SIC 2873-2879) 187,800 8,640, 8003 N/A 39,487, goo4 1,502,700 12,961, 200~,

Food and Kindred Chemicals w I (SIC 20) N/A N/A N/A NIA N/A N/A c. m Ind us tr i a1 Organic 3 3 Chemicals (SIC 2819) 1,668,000 38,058,7003 255,700 22,418,500 1,369,500 59,662,700

Leather and Leather Products (SIC 31) 1,200 1,200 NIA N/A 12,300 9,800

Machinery, Except Electrical 6 6 (SIC 35) N/A N/ A N/A 19,300 135,500 38,700

Pulp and Paper Industry (SIC 26) 5,962,300 579,700 N/A 862,700 N/A N/A

Pe t r o 1e um Re fining Industry (SIC 29) N/A N/A 753,300 N/A 523, 5o05 N/A

Ph armace ut ica1 Preparations (SIC 2834) N/A N/ A N/A N/ A 219,400 N/A

li I' Table 3-4 (continued)

On-S i te Of f-Si te Sur face Land Land 1 Industry Land fill Impoundment Applications Other Disposal Other

Plastics and Resins Manufacturing (SIC 2821) 378,500 30,513, 7003 43,200 26,146,400 392,400 34,914,60O7

Primary Iron and Steel Manu- fac turing and Ferrous Foundries (SIC 3312 - SIC 3321) 14,563,000 14,563,000 NIA 39,441, 4004 NIA NI A

Primary Non-Ferrous Metals Manufacturing and Non-Ferrous Foundries (SIC 3330-3399) 233,900 147,300 NIA NIA 78,000 NIA

W I Totals 22,994,700 121,002,200 1,052,200 128,376,200 4,233,300 107,587,000 -- -~

aWastes managed in surface impoundments and land application units are reported in wet metric tons.

'Includes only industries for which there are estimated quantities of wastes being managed by the above-listed methods. The quantities listed above may represent the entire industry or only one waste stream within an industry.

2N/A = Data not available.

3Dry or wet weight not specified; assume wet weight.

4Mostly waste piles.

5>fostly land application; see Section 4.4.2.

'Managanent method unknown.

Ii I The primary iron and steel, electric power, organic chemical, and plastic and resin industries account for 75% of all industrial non-hazardous waste known to be managed on-site. The same four industries are among the top five producers of'non-hazardous wastes.

Industrial Wastewater Treatment

Figure 3-1 illustrates the relative industrial water intake of various industries in the U.S. The estimates for energy requirements for industrial wastewater treatment range from 0.6 to 0.8 quads of primary energy. The distribution of energy needed for industrial water pollution control among various industries can be estimated from Figure 3-1; that is, based on the data an estimated 90% of the total energy consumed for industrial wastewater treatment is used by the metal, chemical, paper, petroleum, and food processing industries--the largest water users. There is, however, insufficient data available to make a truly accurate estimation of the energy needed for industrial wastewater treatment. Tab1 e 3-5 summarizes the types of industrial liquid wastes and typical methods used for treatment.

AGRICULTURAL WASTES

The agricultural industry is the largest source of solid waste production in the United States. Current estimates on annual generation of solid waste are between 2300 and 3300 million metric tons, representing 50% of all wastes generated in the U.S. annually. Agricultural waste includes residues from crop growing, harvesting, and processing; meat, poultry, and dairy products; and hogging and wool operations.

Management Tec hnol ogi es

Field application is by far the most common form of agricultural waste disposal, due primarily to the largely organic nature and remote locations of the sources of this waste. Other technologies available for disposal/resource recovery include incineration, pyrolysis, and methane production.

MINING WASTES

Next to agriculture, the mineral/mining industry is the largest producer of sol id wastes. The annual generation rates are estimated at over 2,000 million metric tons.

3-18 61-E

PERCENT OF TOTAL WATER INTAKE BY INDUSTRY

a 0 0 e, s 0” I I I I

PRIMARY METALS I

7 4. (P CHEMICALS S m1 w I w PAPER

U 3 P I= v, PETROLEUM ct 2. I nl -I r nl FOOD ct m I 1

U 3 TRANSPORT mplct EQUIPMENT or sm 7 7 0 4. m3 STONE, .. CLAY, & r+ J GLASS wm 7 m ?C wy MACHINERY R 7 0 0 7 P FOREST 4. PRODUCTS 3 (cl 7 rt 0 RUBBER & H PLASTIC 3 a S 7 v, ct 1 4. FABRICATED 2 METALS 7 -U 1 0 P ELECTRICAL S EQUIPMENT 0 rt 7 1 INSTRUMENTS

MISC. Table 3-5 SUMMARY OF NON-HAZARDOUS INDUSTRIAL WASTEWATER: ITS ORIGIN, CHARACTER, AND TREATMENT

Industries Origin of Major Major treatment and producing wastes major wastes characteristics disposal methods

Apparel Textiles Cooking of fibers; Highly alkaline, colored, Neutralization, desizing of fabric high BOD and temperature chemical precipita- high suspended solids tion, biological treatment, aeration, and/or trickling filtration Leather goods Unhairing, soaking, High total solids, Equalization, sedi- deliming, and bating hardness, salt, sulfides, mentation, and of hides chromium, pH, precipita- biological ted lime, and BOD treatment Laundry trades Washing of fabrics High turbidity, alkalin- Screening, chemical w I ity, and organic solids precipitation, flo- Iv 0 tation, and adsorption Food and drugs Canned goods Trimming, culling, High in suspended solids, Screening, lagoon- juicing, and blanch- colloidal and dissolved ing, soil absorp- ing of fruits and organic matter tion or spray vegetables irrigation Dairy products Dilutions of whole High in dissolved organic Biological treat- milk, separated matter, mainly protein, ment, aeration, milk, buttermilk, fat, and lactose trickling filtra- and whey tion, activated sludge Brewed and Steeping and press- High in dissolved organic Recovery, concentra- distilled ing of grain; resi- solids, containing nitro- tion by centrifuga- beverages due from distilla- gen and fermented tion and evaporation, tion of alcohol; starches or their trickling filtration; condensate from products use in feeds; diges- stillage evaporation of slops tion

I! I il 1 Table 3-5 (continued)

Industries Origin of Major Major treatment and producing wastes major wastes characteristics disposal methods

Meat and Stockyards; slaugh- High in dissolved and Screening, settling poultry tering of animals; suspended organic matter, and/or flotation, products rendering of bones blood, and other proteins trickling filtration and fats; residues and fats in condensates; grease and wash water, picking of chickens Animal feedlots Excreta from animals High in organic sus- Land disposal and pended solids and BOD anaerobic lagoons Beet sugar Transfer, screening, High in dissolved and Reuse of wastes, w and juicing waters; suspended organic coagulation, and I N drainings from lime matter, containing lagooning w sludge; condensates sugar and protein after evaporator; juice and extracted sugar Pharmaceutical Mycelium, spent High in suspended and Evaporation and products filtrate, and wash dissolved organic drying; feeds waters matter, including vitamins Yeast Residue from yeast High in solids Anaerobic diges- filtration (mainly organic) tion, trickling and BOD filtration Pickles Limewater; brine, Variable pH, high Good housekeeping alum and tumeric, suspended solids, screening, equali- syrup, seeds and color and organic zation pieces of cucumber matter Coffee Pulping and ferment- High BOD and suspended Screening, settling of coffee bean solids ing, and trickling filtration Table 3-5 (continued)

Industries Origin of Major Major treatment and producing wastes major wastes characteristics disposal methods fuge; pressed fish; organic solids, and total waste; barge evaporator and other odor remainder to sea wash water wastes Rice Soaking, cooking, High BOD, total and Lime coagulation, and washing of suspended solids digestion rice (mainly starch) Soft drinks Bottle washing; High pH, suspended Screening, plus floor and equip- solids, and BOD discharge to ment cleaning; municipal sewer syrup-storage- tank drains Bakeries Washing and greas. High BOD, grease, Amenable to bio- ing of pans; floor floor washing, sugars, logical oxidation washings flour, detergents Filter backwash; Minerals and suspended Direct discharge W LVater production I lime-soda sludge; solids to streams or Iu r\) brine; alum sludge indirectly through holding lagoons >laterials Pulp and paper Cooking, refining, High or low pH, color, Settling, lagoon- washing of fibers, high suspended, col- ing, biological screening of paper loidal, and dissolved treatment, aera- Pulp solids, inorganic tion, recovery of fillers by-products Photographic Spent solutions of Alkaline, containing Recovery of silver; products developer and fixer various organic and discharge of wastes inorganic reducing into municipal agents sewer Steel Coking of coal, Low pH, acids, cyano- Neutralization, washing of blast- gen, phenol, ore, coke, recovery and reuse, furnace flue gasses, limestone, alkali, oils, chemical coagulation and pickling of mill scale, and fine steel suspended solids \letal-plated Stripping of oxides, Acid, metals, toxic low Alkaline chlorina- products cleaning and plating volume, mainly mineral tion of cyanide; of metals matter reduction and precipitation of

'I I Table 3-5 (continued)

Industries Origin of Major Major treatment and producing wastes major wastes characteristics disposal methods

~~ chromium; lime precipitation of other metals Iron-foundry Wasting of used High suspended solids, Selective screening- products sand by hydraulic mainly sand; some ing, drying of discharge clay and coal reclaimed sand Oil fields Drilling muds, salt, High dissolved salts Diversion, recov- and refineries oil and some natu- from field; high BOD, ery, injection of ral gas; acid sludge odor, phenol, and sul- salts; acidifica- and miscellaneous fur compounds from tion and burning oils from refining refinery of alkaline sludges Fuel-oil use Spills from fuel- High in emulsified Leak and spill W I tank filling waste; and dissolved oils prevention, rJ w auto crankcase oils flotation Rubber Washing of latex, High BOD and odor, high Aeration, chlorin- coagulated rubber, suspended solids, vari- ation, sulfonation, exuded impurities able pH, high chlorides biological treatment from crude rubber Glass Polishing and Red color, alkaline Calcium-chloride cleaning of glass nonsettleable sus- precipitation pended solids Naval stores Washing of stumps, Acid, high BOD By-product recovery, drop solution, sol- equalization, recir- vent recovery, and culation and reuse, oil-recovery water trickling filtration Glue manufacturing Lime wash, acid High COD, BOD, pH, Amenable to aerobic washes, extraction chromium, periodic biological treatment, of nonspecific strong mineral acids flotation, chemical proteins precipitation Wood preserving Steam condensates High in COD, BOD, Chemical coagula- solids, phenols tion; oxidation pond and other Table 3-5 (continued)

Industries Origin of Major Major creacment ana prod uc i n g wastes major wastes characteristics disposal methods aerobic biological treatment Ca ti c! le Wax spills, stearic Organic (fatty) acids Anaerobic digestion manufacturing acid condensates P 1 y u.0 od Glue washings High BOD, pH, phenols, Settling ponds, manufacturing potential toxicity incineration Chemicals .4 ci ds Dilute wash waters; Low pH, low organic Upflow or straight many varied dilute content neutralization, burning when some organic matter is present Detergents Washing and puri- High in BOD and sapon- Flotation and fying soaps and ified soaps skimming, precipi- detergents tation with CaClz w Cornstarch Evaporator conden- High BOD and dissolved Equalization, bio- N sate or bottoms organic matter; mainly logical filtration, P when not reused or starch and related anaerobic digestion recovered, syrup material from final washes, wastes from

" bottling-up'' process Explosives Washing TNT and TNT, colored acid, odor- Flotation, chemical guncotton for ous, and contains organic precipitation, bio- purification, acids and alcohol from logical treatment, washing and pick- powder and cotton, aeration, chlorina- ling of cartridges metals, acid, oils, and tion of TNT, neutral- soaps ization, adsorption Pesticides Washing and puri- High organic matter, Dilution, storage, fication products benzenerigh structure, activated carbon such as 2,4-D, and toxic to bacteria and adsorption, alka DDT fish, acid line chlorination Phosphate and Washing, screening, Clays, slimes and tall Lagooning, mechani- phosphorus floating rock, con- oils, low pH, high cal clarification, denser bleedoff suspended solids, coagulation and from phosphate phosphorus, silica, and settling of refined reduction plant fluoride waste

il I ii Table 3-5 (continued)

Industries Origin of Major Major treatment and producing wastes major wastes characteristics disposal methods Formaldehyde Residues from manu- Normally high BOD and Trickling filtration, facturing synthetic HCHO, toxic to bacteria adsorption on acti- resins and from in high concentrations vated charcoal dyeing synthetic fibers Plastics and Unit operations Acids, caustic, dissolved Discharge to muni- resins from polymer prepar- organic matter such as cipal sewer, reuse, ation and use; phenals, formaldehyde, controlled discharge spills and equip- etc. ment washdowns

W I Energy N cn Steam power Cooling water, Hot, high volume, high Cooling by aeration, boiler blowdown, inorganic and dissolved storage of ashes, coal drainage solids neutralization of excess acid wastes Coal processing Cleaning and class- High suspended solids Settling, froth ification of coal, mainly coal; low pH, flotation, drainage leaching of sulfur high H2S04 and FeS04 control, and sealing strata with water of mines Nuclear power and radioactive materials Processing ores; Radioactive elements, Concentration and laundering of can be very acid and containing, or contaminated clothes; “hot” dilution and research-lab wastes; dispersion processing of fuel; power-plant cooling waters

Source: Ref. 3

I Ii i Types of Waste

Mining wastes are usually described as being either waste rock, the coarse materials that were excavated to expose the ore during mine development; or tailings, the residues obtained by the separation of minerals from their ores. Wastes from the sizing and cleaning coal , whether from underground mining or from strip mining operations, are defined as coal refuse. Such wastes may contain mine rock, carbonaceous shale, pyrites, and other debris.

Management Tec hnol ogies

Land application, or disposal in landfills, is the most common method of waste management for mining wastes. There is, however, a small percentage of such wastes that are used in the construction industry, though this utilization is somewhat limited by the proximity of the construction site to the mine. Table 3-6 lists estimates of the amounts of waste rock, mill tailings, and coal refuse produced in the major mining industries each year.

3-26 Table 3-6

ESTIMATED AMOUNTS OF WASTE PRODUCTS IN THE MAJOR MINING INDUSTRIES

Waste Rock Mill Tailinrp Estimated Accumulated Mining Annud Quantity. Annual Quantity Mill ailin Possible Uses of Tailings Industry (106- tons 1 (lo6 tons) (10TmnsT in Construction Copper 624 234 7,700 Brick, embankments, mineral filler in bituminous mixtures Dredge spoil 270-360 - Uncertain Landf iI I Taconite 100 109 3,600 Concrete aggregate, skid-resistant aggregate, building block Coal .. >100"' 2,700"' Highway construction, land and minef il I Phosphate 230 54t 907tt Landfill. dikes for ohosohate slimes Iron ore 27 27 7 30 Concrete aggregate' ' Gold 15 5 4 50 Biick, sand and gravel, mineral filler Uranium 156 5.8 110 None because of concern with low level radioactivity Lead 0.5 8 180 Mineral filler in bituminous mixtures; refractory brick Zinc 0.9 7.2 180 Mineral filler in bituminous mixtures. refractory brick Quarry 68 - Uncertain Aggregate Gypsum 14.2 2.7 Uncertain Brick Asbestos 0.6 2 14 Ceramic tile, refractory brick, mineral filler in bituminous mixtures Barite 1.9 3.1 24 Road surfacing material Fluorspar 0.1 0.4 Uncertain Aggregate Feldspar 0.2 0.8 Uncertain Manufacture of brick and lightweight building materials 'Includes overburden in some cases. 0. Included in tailings. 0.. Coal refuse, which includes mine rock, shale, pyrite and other mining debris. t Includes both phosphate slimes and phosphogypsum. ttlncludes estimated 136 x lo6 tons of phosphogypsum.

Source: Ref. 4

3-27 REFERENCES

1. SAIC. Summary of Data on Industrial Non-Hazardous Waste Disposal Practices. McLean, VA: 1985.

2. JRB Associates Mclean, VA 1983

3. F.W. Owen. Energy in Wastewater- Treatment. 1982. 4. S.O. Renfree. -Building Materials from Solid Waste. 1979. 5. JRB Associates. Solid Waste Data. McLean, VA: 1981.

3-28 Section 4

HAZARDOUS INDUSTRIAL WASTES

CHARACTERIZATION AND QUANTITIES OF HAZARDOUS WASTES

Many studies have been conducted to develop statistics on the quantity, types, and origins of hazardous wastes. Table 4-1 summarizes the results of these studies and the reasons for the great discrepancies between them.

One of the most recent and reliable studies available was completed by the Congres- sional Budget Office (CBO) in May 1985. The model used in the study assumes that industries generate a characteristic set of wastes at rates which are a function of process technology, industrial output, and production efficiency. More specifically, the waste generation rates are estimated from waste generation quantites and employment data collected from state agencies, the EPA, and Dun and Bradstreet. The projections of waste generation are further based on predicted employment growth of industry, as supplied by the Bureau of Labor Statistics.

The CBO report includes all wastes defined as hazardous by the EPA in addition to waste oils, PCBs, air pollution control dusts, industrial scrubber sludges, and certain liquid hazardous wastes. A complete list of the types of hazardous wastes included is presented in Table 4-2.

The CBO waste generation model estimates that for 1983 between 223 and 308 million metric tons (MMT) of hazardous wastes were generated; this range represents the 95% confidence interval for a mean estimate of 266 MMT. Table 4-3 lists by type of management the quantities of waste generated, with figures based on estimates Of 70 major waste-producing industries. The EPA estimated that in 1981 these industries generated 95% of the total national hazardous wastes. The top 12 hazardous waste generating industries are listed in Table 4-4 together with estimates of the quantity of wastes generated in 1983.

The chemical industries produced an estimated 127 MMT, or almost half of all hazardous waste produced in the nation. Inorganic liquids and sludges generated by the industrial inorganic chemical industry made up about 19% of the total, while 17.5% was comprised of organic and inorganic liquids contributed by the industrial

4- 1 Table 4-1

DATA SOURCES FOR THE QUANTITY OF HAZARDOUS WASTE GENERATED IN US DATE /MILLIONS OF METRIC TONS) SOURCES OF STUDIES -

BATTELLE COLUMBUS LABORATORIES 1977 - DEVELOPMENT PLANNING & RESEARCH ASSOC. 1980-1 38 BOOZ, ALLEN & HAMILTON 1980 28-54 SAlC 1981 41 EPA - OFFICE OF SOLID WASTE MNGMT 1980,1981 41,43 ARTHUR D. LITTLE 1979 - FROST & SULLIVAN 1980 60 P WESTAT, INC. 264 I 1981 N ASSOC. OF STATE TERRITORIAL SOLID WASTE MNGMT 1981-2 255-275 CONGRESSIONAL BUDGET OFFICE 1985 267

VARIATIONS RFWFFN STL JIWS ARF nl IF TO. O .DEFINITION OF HAZARDOUS WASTE O METHODOLOGY USED O DIRECT INDUSTRIAL INFORMATION O US DEPT OF COMMERCE VISITING SMALL NUMBER OF NUMBER OF "TYPICAL" FACILITIES AND EXTRAPOLATING O THEORETICAL MODELS BASED ON NUMBER OF HW PRODUCERS NATIONWIDE O ASSUMPTIONS CONCERNING WASTE GENERATION AND MANAGEMENT DEGREE OF COMPLIANCE WITH REGULATIONS Table 4-2

A CBO WASTE CLASSIFICATION SYSTEM Based on Major Constituent and Physical State

Waste Type Examples

Liquids Waste Oils Spent crankcase oil, industrial lubricants Halogenated Solvents Spent trichloroethylene, chloroform, carbon tetrachloride Non halogenated Solvents Spent acetone, methylethyl ketone Other Organic Liquids Aqueous organic solutions from cleaning or degreasing operations Metal-Containing Liquids Metal finishing colutions (acidic or alkaline) Cyanide and Metal Liquids Neutralized acid or basic washes with cyanide salts Polychlorinated Biphenols (PCBs) Transformed fluids Nonmetallic Inorganic Liquids Acid or basic solutions without metlals

Sludges Oily Sludge Tank bottoms, oil/water separation sludge Halogenated ORganic Sludge Halogenated still bottoms Nonhalogenated ORganic Sludge Still bottoms without halogens Metal-Containing Sludge Electroplating or chrome pigments, wastewater treatment sludges Cyanide and Metal Sludge Metal heat treating sludges Nonmetallic Inorganic Sludge Sulfur sludge, lime sludge Dye and Paint Sludge Heavy metal and solvent sludges Solids Contaminated Clay, Soil, Sand Clay filters, spilled material Metallic Dusts and Shavings Primary metal dusts and metal machinery wastes, emission control dusts from steel and lead industries Nonmetallic Inorganic Dusts Precipitator or baghous wastes Halogenated Organic Solids Polyvinyl Nonhalogenated Organic Solids Polyethylene, cyclic intermediates

Mixed Pesticides, Herbicides Pesticides, dioxins, and other production wastes Explosives TNT, wastewater treatment sludges from expolosives production Miscellaneous Wastes Lab waste chemicals, equipment, containers, unspecified wastes Resins, Latex, Monomer Phenols, epoxy, polyester

Source: Congressional Budget Office.

4-3 Table 4-3

ESTIMATED NATIONAL GENERATION OF INDUSTRIAL HAZARDOUS WASTES 1983, Ranked by Waste Quantity Management Technologies (Thousands of Metric Tons)

Percent Quantity of Techno1 ogy Desc ript i on Ma nag ed Total

Injecti on Injection of liquid wastes into wells or 66,800 25 We1 1 salt caverns

Sewer and Discharge of treated and untreated 58,900 22 Direct liquids to municipal sewage treatment Discharge plants, rivers, and streams

Surface Placement of liquid wastes or sludges in 49,500 19 Impoundment pits, ponds, or lagoons

Hazapdous Placement of liquid or solid wastes into 34,200 13 Waste lined disposal cells that are covered by Landf i11 soi 1s

Sanitary Placement of wastes in unlined dump 26,700 10 Landfi 11 sites, which normal ly receive only inert, nonhazardous material s

Disti1 lation Recovery of solvent liquids from other 10,900 4 waste contaminants through fractional disti 11 ation

Industrial Burning of wastes in industrial and 9,500 4 Boilers commercial boilers as a fuel supplement

Ox idat i on Chemical treatment of reactive wastes 3,000 1

Land Biodegradation of liquid wastes or 2,900 1 Treatment sludges in soils

Incineration Burning of wastes in advanced technology 2,700 1 incinerators meeting stringent environment standards

Ion Recovery of metals in solution through 500 a Exchange membrane separative techniques

265,585

Source : Congressi onal Budget Offi ce. a. Less than 1 percent.

4-4 Table 4-4

ESTIMATED NATIONAL GENERATION OF INDUSTRIAL HAZARDOUS WASTES Ranked by Major Industry (Thousands of Metric Tons)

Estimated Percent Quantity of Major Industry in 1983 Total

Chemicals and Allied Products 127,245 47.9 Primary Metals 47,704 18.0 Petroleum and Coal Products 31,358 11.8 Fabricated Metal Products 25,364 9.6 Rubber and Plastic Products 14,600 5.5 Miscellaneous Manufacturing 5,614 2.1 Nonelectrical Machinery 4,859 1.8 Transportation Equipment 2,977 1.1 Motor Freight Transportation 2,160 0.8 Electrical and Electronic Machinery 1,929 0.7 Wood Preserving 1,739 0.7 Drum Reconditioners 45 b

Total 265,595 100.0

SOURCE: Congressional Budget Office. a. See CBO, Empirical,Analysis, Table 1 for the master list of specific industry types that are aggregated into the major industry groups presented in this table. b. Less than one-tenth of one percent.

4-5 organic segment. The second largest contributor was made up of the primary metals industries, with approximately an 18% share (48 MMT) of the total. Half of these wastes were in solid form and consisted of solidified residues from primary metal foundries, dry 1 ime from scrubbing operations, and dusts captured by electrostatic precipitators and baghouses.

The petroleum products industries ranked third in the study. Approximately 41% of their wastes consisted of oily sludge and waste oil, with nearly 29% consisting of spent ha1 ogenated and nonhalogenated sol vents used in degreasi ng operations. The fabricated metal products industries contributed almost 10% of the national total , with inorganic liquids and metal-bearing sludges making up all 25 MMT of these wastes.

Only about 10 MMT (4%) of the hazardous wastes generated in the nation were estimated to have been treated off-site (Table 4-5). Most wastes are treated and disposed of on-si te, since most hazardous materials are produced by large industrial plants who benefit from the economies of scale. The ability to eliminate transportation costs by managing their own wastes is a strong incentive for such companies. Furthermore, large industrial customers can obtain permits for on-si te disposal more easily than can smaller, off-si te treatment plants.

WASTE MANAGEMENT PRACTICES

A main purpose of described in the 1984 Resource Conservation and Recovery Act (RCRA) Amendments (Section 8) was to limit or ban land disposal methods such as surface impoundment, deep well injection, and landfilling. A shift toward advanced treatment, incineration , recycling, and other management techniques is encouraged by the legislation. Specific statutory deadlines to regulate and change various management practices were set by RCRA; however, many of the new limitations have not yet taken effect and the CBO predicts that management practices will not change significantly until they do. For example, the following deadlines required under RCRA to be issued by EPA by the fall of 1986 will be missed: procurement guidelines for fly ash, tires and oil; standards for containerized liquids in landfills; and decisions on air emissions, inorganic chemical wastes, and refining wastes.

The report estimates that in 1983, 68% of all hazardous waste was estimated to be managed by land disposal techniques (Table 4-6). Deep-well injection was the most commonly used method, for a number of reasons: it is relatively inexpensive, ample capacity exists, and injection wells are easier to establish than other types of land treatment facilities. However, due to the land disposal bans set by RCRA it is

4-6 Table 4-5

ON- AND OFF-SITE WASTE FLOWS MANAGED BY MAJOR INDUSTRY GROUPS IN 1983 (Millions of Metric Tons)

Percent Flow of To tal a On- Off- On- Off- Major Industry Site Site Site Site

Chemicals and Allied Products 125.9 1.2 99 1 Primary Metals 47.3 0.3 98 2 Petroleum and Coal Products 31 .O 0.3 99 1 Fabricated Metal Products 24.8 0.6 98 2 Rubber and Plastic Products 11.5 3.0 80 20 Miscellaneous Manufacturing 4.5 0.9 83 17 Nonelectrical Machinery 4.3 0.6 88 12 Transportation Equipment 2.5 0.5 83 17 Motor Freight Transportation 0.2 2.0 11 89 Electrical and Electronic Machinery 1.7 0.2 90 10 Wood Preserving 1.7 b 100 0 Drum Reconditioners b b -11 -89

Total 255.0 10.3 96 C 4c

SOURCE: Congressional Budget Office. a. Percents were calculated before rounding. b. Less than 0.1 million metric tons. c. Weighted average.

4- 7 Table 4-6

ESTIMATED HAZARDOUS WASTE DISPOSAL QUANTITIES BY MANAGEMENT TECHNOLOGY 1983 and 1990 - Under Alternative Cases (Millions of Metric Tons)

1990 1990 ~ ~~ Quantity Quantity Quantity With KO With in Waste Waste Tech no 1ogy 1983 a Reduction Reduction

Injection We 11 66.8 50.7 41.6 Sewers and Direct Discharge e 58.9 60.9 36.7 Surface Impoundment 49.5 11.2 10.8 Hazardous Waste Landfill No pretreatment 34.2 22.2 22.2 With stabilization d 70.7 66.1 Sanitary Land fi 1 26.7 11.3 10.7 Distillation 10.9 11 .o 9.5 Industrial Boilers 9.5 12.1 9.0 Oxidation 3.0 7.6 5.2 Land Treatment 2.9 5.7 4.8 Incineration 2.7 11.6 8.2 Ion Exchange 0.5 0.9 0.5 Solvent Extraction d 0.9 0.9 Oil Rerefining d 2.8 2.4 Metal Recovery d 1.2 0.5

Total 265.6 280.8 229.1

Percent Change from 1983 5.6 -13.7

SOURCE: Congressional Budget Office. a. Mean estimate of waste generation under pre-1984 RCRA policies (see Table3 in Chapter 11). b. Projection based on no waste reduction 1990 case in Table 12. c. Projection based on waste reduction case in Table 12. d. Less than 0.5 million metric tons. e. Wastes entering this category are treated residuals from other treatment and disposal processes or wastes disposed of in compliance with Clean Water Act regulations, which should pose little or no threat to the environment.

4- a estimated that the direct disposal of hazardous waste into injection wells will decrease an estimated 24% by 1990, assuming that waste reduction practices are carried out. In fact, a reduction rate as high as 38% is projected, if it is assumed that industry will choose to avoid higher disposal costs by implementing waste reduction practices.

Another estimated 50-MMT or about 19% of hazardous wastes were disposed of in surface impoundments, which are natural topographic depressions or man-made excavations designed to hold liquid wastes or wastes containing free 1 iquids. EPA estimates that 90% of these impoundments may leak some of the waste they contain into ground and surface water; therefore, CBO predicts a 77% drop by 1990 in the use of this disposal method. The final 13% or 34 MMT of waste for the year being analyzed consisted of hazardous waste landfi 11 s. This amount is predicted to decrease by up to 35%, if waste or water reduction options are taken by industry.

Current costs to industry for waste disposal were estimated to be $4.2 to $5.8 billion in 1983 (Table 4-7). The lower value was determined assuming lower unit costs for land disposal technologies not yet in full compliance with current regulations; currently there are many such facilities operating under interim approval from EPA. The higher cost estimate assumes full compliance with the Clean Water Act.

The implementation of new treatment and incineration facilities is heavily dependent on the higher disposal costs for hazardous materials due to the tougher land disposal requirements under RCRA (Table 4-8). Impediments to new facilities include opposition from communities surrounding proposed treatment sites; differential tax rates for waste managed at commercial and private, on-site facilities; and restrictions on the transportation of hazardous waste across county and state borders (1).The predicted cost changes listed for each of the main industries affected by RCRA are presented in Table 4-9.

HAZARDOUS WASTE TREATMENT TECHNOLOG I ES

At the present time there are a number of advanced technologies for hazardous waste disposal that are being researched. Many of these technologies show promise of becoming commercially available in the near future given implementation of the 1984 RCRA amendments.

4- 9 Table 4-7

ANNUAL EXPENDITURES BY MAJOR INDUSTRY GROUPS FOR HAZARDOUS WASTE MANAGEMENT 1983 Base1 ine Pol icy (Millions of 1983 Dollars)

Partial Full Compliance Compliance Major Industry Estimate Estimate

~~ Chemicals and Allied Products 894 1,544 Primary Metals 1,110 1,243 Fabricated Metal Products 750 899 Rubber and Plastic Products 549 798 M i sce 11a neou s Manufacturing 130 267 Nonelectrical Machinery 207 254 Motor Freight Transportation 208 229 Transportation Equipment 124 191 Electrical and Electronic Machinery 109 156 Petroleum and Coal Products 70 136 Wood Preserving 46 56 Drum Reconditioners 5 6 Total 4,202 5 * 779

SOURCE: Congressional Budget Office. b. Assumes lower unit costs for injection wells, landfills, and surface impoundments only.

4-10 Table 4-8

RANGE OF ESTIMATED ANNUAL INCREMENTAL COSTS TO INDUSTRY OF 1984 RCRA AMENDMENTS, BY 1990 (Millions of 1983 Dollars)

Program Element Annual Cost

Land Disposal Prohibition 2,650-5,422 Sanitary Landfill (Subtitle D)a 1,000--2,000 Burning and Blending Requirement 456-1,620 small Generators b 100--300 New Technological Requirements 40-75

Total 4,246-9.41 7

SOURCE: Congressional Budget Offce, in part based on data obtained from the Environmental Protection Agency. a. The SubtitleD program includes retrofit requirements for sanitary landfills, such as municipal solid waste landfills. Program costs are uncertain, because it is difficult to predict how many facilities will be required to meet the more stringent standards applicable to hazardous waste landfills. The estimate in this table, therefore, does not indude any of the corrective action requirements of new RCRA Section 3004(t). Assuming all Subtitle D facilities must install groundwater monitoring systems, corrective action (40 CFR 264.100) is required at only 20 percent of municipal facilities and LO percent of industrial facilities, and liners are required at 20 percent of municipal sites and 5 percent of industrial facilities, annual costs could increase by, $4 billion to $7 billion. Full application of current hazardous waste landfill standards to all Subtitle D facilities could increase annual costs by $10 binion to $25 billion. b. Estimated by the Environmental Protection Agency, Ofice of Policy Analysis (1984).

4-11 Table 4-9

ESTIMATED RANGE OF ANNUAL INDUSTRIAL EXPENDITURES FOR HAZARDOUS WASTE MANAGEMENT, 1983 AND 1990 Under A1 ternative Cases

1990 1990 cost cost cost With No With in Waste Waste Major Industry 1983 a Reduction Reduction

Chemicals and Allied Products 1,544 3,122 2,283 Primary Metals 1,243 2,302 1,661 Fabricated Metal Products 899 1,191 735 Rubber and Plastic Products 798 2,026 1,771 Miscellaneous Manufacturing 267 356 308 Nonelectrical Machinery 254 324 279 Motor Freight Transportation 229 247 247 Transportation Equipment 191 360 286 Electrical and Electronic Machinery 156 237 163 Petroleum and Coal Products 136 940 634 Wood Preserving 56 91 61 Drum Reconditioners 6 6 2

Total 5,779 11,201 8,429

Incremental Change from 1983 5,422 2,650

Percent Change from 1983 __ +93.8 +45.8

SOURCE: Congressional Budget Office. a. Assumes full compliance with RCRA regulations hefore the 1984 amendments,

4-12 A good number of the advanced technologies are electrically powered and may thus represent a potential load growth for certain utilities. The following subsections describe the most important hazardous waste disposal technologies that are currently being researched or are in some limited commercial application, with an emphasis on techniques requiring moderate to high electrical energy use.

Air Flotation

Description. Air flotation is used to separate dispersed liquids or suspended solids from liquids. Three types of flotation processes are discussed below: dissolved air flotation, dispersed air flotation, and microgas dispersion separation.

In a dissolved air flotation process compressed air is first injected into the pressure tank containing the waste feed. After the air has dissolved in the solution, pressure is lowered in the tank thereby creating tiny air bubbles. Particles are captured by the bubbles and carried to the surface where they are skimmed off. The water in this surface sludge blanket can be recycled or discharged to pub1 icly-owned treatment works (POTWs) .

Dispersed air flotation follows the same steps as the process above, except that the air is introduced beneath the waste solution via some type of dispersion screen. The floc then attaches to the air bubbles and they rise to the surface together.

Microgas dispersion separation (MGD) involves the use of a surfactant compatible with the creation of a uniform dispersion of extremely small gas bubbles and the extraction of a particular substance. Further research is needed, however, to identify those surfactants which are suitable for extracting toxic materials from water.

Applications. Air flotation is used primarily by the mineral industry to separate valuable ore constituents from waste tailings. In 1970 there were 240 flotation systems in the U.S. processing 27 different types of ores. In this process, ore is ground and mixed with water to form a slurry. Various reagents such as frothers, flocculants, depressants, and modifiers are then added in order to alter the surface characteristics of the mineral particles to allow them to float on the surface, making recovery possible (Figure 4-1). Of course, care must be taken so as not to introduce toxic reagents that may be left in the tailings water. In addition to ore recovery, several flotation plants have been used to remove pigments, ink, and coatings during the recovery of cellulose from recycled paper.

4-13 r\ 11lClRO MACNll

VIIRaTINC

CONI CYUSMCL

*?ION OR1 lllDlR IlNI OR1 SIN

Jaw CRUSHER

AUlOYATIC 1101AllON MACHINI IOUOHCIS i SAMPLER

LI TO 1AlllNOI ?ON0

h \ SAND PUMP

OlSC FILTER

CONCCNIRAIII

Figure 4-1. A Typical Air Flotation System Used in the Mineral Industry

Source: Ref. 2, p. 537

4-14 Control Panel ’-+ Handrails I

.. 1 3---- Base Slab Scraper Mechanism Sludge Sump

Figure 4-2. IWS Recycle Pressuri zation System

Source: Industrial Waste Treatment Equipment, Thomasville, Georgia

4-15 Commercial dissolved-air flotation units for hazardous waste treatment are manufactured by several firms including Davis Water and Waste Industries, Inc. of Thomas- ville, Georgia, a division of Industrial Waste Systems (IWS). Figure 4-2 illustrates a recycle pressurization system built by IWS. This type of system has markets in food processing, chemicals, metals, pulp and paper, tanning, refining, and sludge thickening.

Energy and Cost. A functional use breakdown of the electrical energy needs for a typical ore flotation process is given in Table 4-10. For example, an IWS dissolved-air flotation unit using a 100-hp pump to recycle 1800 gpm requires approximately 6 to 7kWh per 100 gallons of influent. As is evident from the data, the grinding or size reduction step is the major energy consuming point in the process. However, this step would most likely not be necessary for hazardous material treatment since the wastes would probably be in solution or in the form of a slurry.

The capital cost of a 40-foot diameter system built by IWS ranges from $130,000 to $150,000 including erection at the job site. Processing costs, on the other hand, vary considerably with the type and amount of ore processed. For example, a study done by NATO in 1981 lists operating costs of $4 and $1.50 per ton of sulfide ore for plants processing 500 and 10,000 tons per day, respectively.

Biological Treatment --I___ Description. Biological treatment decomposes wastes by mixing them with the appropriate microorganisms. Table 4-11 lists several of the most common of these biological processes with concomitant operating parameters and brief descriptions for each. It should be noted that while energy is needed for pumping and dispersing oxygen in the mixtures, the only processes on the list which use a substantial amount of electrical energy (>lo% of total cost) are activated sludge treatment and aerated lagoons.

Recent legislation discourages the use of land treatment techniques such as lagoons. However, the activated sludge process is carried out in tanks and is subsequently unaffected by the land ban legislation. This is is a well-developed biological treatment technique used to decomposi te organics in streams containing less than 1% particulates. The process is shown on Figure 4-3 and begins with exposing the feed wastewater to a biological floc recirculated from a clarifier (this step is known as equalization) then the solution is thoroughly mixed with oxygen in the aerator to provide the living microorganisms with the environment they

4-16 Table 4-10

ELECTRICAL ENERGY REQUIREMENTS FOR A TYPICAL ORE FLOTATION SYSTEM

kWh/Ton Mi11 ed

Crushing 1.58 Grinding 8.29 F1 otation and Conditioning 2.48 Pumping 0.88 Thickening and Filtration 0.44 Miscel 1 aneous -1.46 15.13*

* Can actually vary from 10-40, depending principally on the ore hardness. Figures shown are average for 20 large flotation plants.

Source: Ref. 2, p. 548

4-17 Table 4-11 OVERVIEW OF BIOLOGICAL TREATMENT METHODS

Energy Chemical EstimatedBOD Demand Demand Principal % Solids Average Upper Limits As % As 96 Microbial optimum Range in Waste Retention Effectively Total Total Total Cost Biological Process Population Temperature inPH Stream Time Organic Decomposed Handled Effluent Radius cost cost 1,000 Gallons

Enzyme Treatment None Mesophilic 1.5-9.5 varies

Activated Sludge Aerobic Hetero- Mesophilic 6-8 < 1% 1 day All bul oil. grease and

Tricking finer Aerobic Hetero- Mesophilic 6-8 < 1% < 1 day All but oil, grease and < 5.000 mg/l Cqand water, Biomass <5%

Waste Stabilization Aerobic Hetem Mesophilic 6-8 <0.1% 3-6 months Mostly carbohydrates < ioomg C9 andwater. NOW < 5% < 5% < 8 Pond trcphic Bacteria proteins. organic acids 1040% influent and Autotrophic and akohds BOD remains Algae

Anaerobic Digestion Obligate Anaer- Thermophilic 6.4-7.5 40% 2 weeks Mostly carbohydrates Not amidle Mixed liquor d ’Stabi- < 5% < 5% 415 obic Heterotm proteins. organic acids hoimass and lized phc Bacteria and alcohols interstitial water, sludge 40-50% influent volatile sludge solids remain

composting Aerobic Hetero- Mesophilic and 5-8.5 <%I%36months All organics, phos- No limit Leachate with NOW trophic Bacteria Thermophilic phorous compounds soluble organics and Facultative and nitrogen com- Anaerobic Hetero- pounds trcphic Bacteria and Fungi Wastewater Wastewater Effluent Influent A . Clarifier

W Aerator

Sludge Residue Recycled Sludge I

Figure 4-3. A Conventional Plug-Flow Activated Sludge System

Source: Ref. 2, p. 199.

4-19 need to break down contaminants. And finally, once decomposition has been accomplished, the solids are separated from the mixture with techniques such as air flotation or gravity settling.

Aerobic microorganisms can decompose many types of organics including aldehydes, polysaccharides , fats , proteins , cycloal kanes , and aromatics , but cannot break down inorganics or such very stable organics as PCBs. However, the process can be used to concentrate these types of hazardous constituents in the form of a sludge. For example, tests done by the state of Texas with assistance from Texas A&M University found the process capable of removing between 20 and 80% of various heavy metals (such as cadmium, arsenic, and zinc) from wastewaters.

Applications. Activated sludge is a secondary biological process commonly used for municipal wastewater treatment. In 1978 over 19,000 million gallons of wastewater were treated by municipal sewage plants, which in doing so consumed about 15 billion kWhs of electricity (10).- The technique is also extensively used for processing industrial effluent streams. It has been used to treat wastewater from a number of industries including pharmaceutical , textile, timber processing , petrochemical , and steel, as well as from breweries, canneries, and pulp and paper mills.

Activated sludge is one of the many technologies which is now being adapted for the treatment of hazardous wastes, although two plants began to use the process in this way as early as 1978. They are Hyon Waste Management Services, Inc. of Chicago, Illinois which handles wastes with up to 10,000 ppm chemical oxygen demand [a measure of the quantity of oxidizable components in water as a means of estimating its degree of contamination (41)]- and BioEcology Systems, Inc. of Grand Prairie, Texas which treats up to 30,000 ppm COD.

CECOS International , with cofunding from the New York State Energy Research and Development Authority and Jet Tech. Inc. , has recently demonstrated their Sequencing Batch Reactor (SBR) on hazardous waste streams. The SBR treats wastes in batches with the functions of equalization, aeration, and sedimentation carried out in one tank sequentially until the entire process is complete. In the more common continuous flow system, the functions are carried out simultaneously in separate tanks .

Studies of the SBR process indicate that it is capable of treating a wide range of chemical industrial wastewaters with flow rates of up to 125,000 gall day. At the Hyde Park Landfill , in a disposal site for chemical wastes, the SBR was selected as

4-20 the most cost-effective alternative for treating leachate. At this site the process removed 85-95% of the total organic carbon (TOC), with further removal hopefully to be accomplished using existing activated carbon facilities.

An SBR system is currently treating hazardous waste water at the CECOS facility in Buffalo, New York, where the majority of the waste is leachate from on-site chemical disposal. The system, which is able to remove 75-80% of the TOC from the leachate, was chosen for its ability to save on carbon regeneration costs, its low space requirements, and its adaptability to varying hydraulic and nutrient loadings.

Energy and Cost.- A1 1 biological treatment process energy requirements for mixing, pumping, and aeration of the wastewater/microorganism mixture are met by electricity.

A hypothetical activated sludge system for the treatment of 1 million gallons per day of hazardous wastewater is shown in Figure 4-4. The energy and cost estimates profile listed in Table 4-12 (1985 dollars) shows that about 40% of the total operating costs are attributable to energy, which breaks down to approximately 1.5kWh per 100 gallons of wastewater treated. Calculations of actual energy consumption at the CECOS SBR site yield a rate of PkWh per 100 gallons of contaminated feedwater. The CECOS SBR site treats typical flows of 70,000 gpd and peak flows of 125,000 gpd. Capital costs for the project are estimated at $1 mi11 ion(- 42).

Electrodialysis

Description. Electrodialysis can be used to separate aqueous salt solutions into dilute and concentrated streams. Contaminated liquid is reduced by the process as it is fed through a stack of alternating layers of cation- and anion-permeable membranes. These special synthetic membranes are placed in an electric field and accomplish the separation by allowing the passage of only either positively or negatively charged ions , as appropriate.

The electric potential is set up by electrodes mounted at each end of the stack. Positive ions attracted by the negative electrodes migrate through adjacent Cation exchange membranes, while negative ions move in the opposite direction through anion exchange membranes. The dynamics of the process are illustrated in Figure 4-5.

4-21 hanical Aerato

P I N N Lime Make-up condary Clarifiers

Legend: Excess Sludge Sludge

A Pumps

Figure 4-4. An Activated Sludge Treatment System Source: Ref. 2, p. 206 Table 4-12

ESTIMATED COSTS FOR AN ACTIVATED SLUDGE SYSTEM 1985 Dol 1 ars*

Activated S1 udge

Basis: 1 x lo6 gallons/day, 10,000 ppm COD, 4,000 ppm BOD, 6,000 ppm MLVSS 365 day/year operation.

Estimated Capital Investment: $1,9000,000

Annual Cost Per Quantity Unit Quantity Annual Cost ($)

Vari ab1 e Costs Operation Labor 8,760 $18.00/ hr $158,000 Maintenance (4% of Inv) 124,000 Lime 400 tons $32.OO/ton 13,000 hmon ia 330 tons 210.00/ton 69,000 Phosphoric Acid 180 togs 550.00/ton 99,000 Electricity 5.3~10 kWh $0.06/ kWh 318,000 Total Variable Costs $781,000

Fixed Costs Taxes and Insurance (2% of Inv) 62,000 Capital Recovery (10 Years @lo%) 620,000 Total Fixed Costs 682,000

Total Costs 1,463,000

Unit cost ($103~~1) $4.00

* SAIC estimates

Source: Ref. 2, p. 207

4-23 Cathode Feed Water Anode I I I I CP 0 I CP 1 AP I I 1 I I I I I I I I I I I I I I I I I I I CP - Cation Permeable Membrane AP - Anion Permeable Membrane Ddute Concentrate Cations in the feed water show the Stream Stream same behavior as sodium (Na'l. and anions the same behavior as chloride (Cl').

Sulfuric Acid, Sodium Hexametaphospha te, Energy Input /IF---

Feed Pump

Positive Negative Electrode Electrode

c, 'Negative Ion Brine Permeable Membrane

e Ion Permeable Membrane

Figure 4-5. The Basic Process of Electrodialysis

Sources: Ref, 2, p. 408; Ref. 3, p. 131

4-24 A number of difficulties are inherent in the process. For instance, a sufficient level of electrolytic conductance must be present to supply the force needed to move ions through the membranes. Operating temperatures must be kept high to lower the resistance through the electrolyte, and removing the salts decreases the conductance ability. The feed system can become clogged with particulate matter, and colloids and polyanions carrying a negative charge can foul the anion exchange membranes. Furthermore, the pH of the catholyte stream decreases during normal cell operation, and is commonly acidified, although running the system at a high pH condition will shorten the normal 5-year lifespan of the membranes.

To control these factors, various measures may be taken. Cell temperature is often raised since power consumption is reduced approximately 1% for every 17OC increase, and pumps are used in conjunction with feedback and control loops to stabilize the pH levels thorughout the system. The feed solution is filtered to prevent clogging, and electrodialysis cells containing "neutral" rather than anion-permeabl e membranes work well to combat anion exchange fouling. It should be noted, however, that implementation of these systems has been limited by their high power requirements.

Applications. Hundreds of electrodialysis units have been installed to produce potable water from brackish water. The process is also used by industry to separate mineral contaminants from streams high in organics. Examples of its use include washing of photographic emulsions, enrichment or depletion processes in the chemical industry, desal ti ng of food products, and treating ammonium fl uoride and hydrogen fluoride effluents from glass and quartz etching facilities.

Electrodialysis is most effective when used to separate a single principle metal ion from an acidic stream, thus it should be useful in nickel , zinc, silver, and gold recovery. Electroplating waste waters would appear to be a particularly good source for this method. To date, pilot-scale testing has been done on several industrial applications (e.g., acid mine drainage and sulfite-liquor recovery) , although no commerc.ia1 systems of interest have been identified. Results from the test plants indicate that the method is exceptionally efficient; streams can be concentrated to as much as 10,000 ppm inorganic salts from original concentrations of 1000-5000 ppm salt, leaving a dilute stream containing 100-500 ppm salt. The ultimate concentration level is thus higher than that achievable by either reverse osmosis or ion exchange.

4-25 --Energy and Cost. All the energy input for electrodialysis is electrical. Arthur D. Little, Inc. (1976) estimated energy requirements at 0.5-kWh for each 1000 ppm reduction of salt in each 100 gallons of purified water, plus an additional 0.5-kWh per 100 gallons of products necessary for pumping.

The estimated energy requirement of an electrodialysis system for sidestream treatment of cooling tower water amounts to approximately 3-kWh/100 gallons. Due to the large amount of salt removed from the waste stream, electricity costs make up almost one half of all direct variable costs, which were estimated to be $1.51 per 1000 gallons. The energy needs of a theoretical electrodialysis plant for NiS04 recovery from nickel plating rinses was estimated at lkWh/100 gallons throughput, for total operating costs of $6.10 per 10,000 gallons (G.ll/kWh). Operating costs for each kilogram of nickel recovered were estimated at $6.90 at a throughput of 10,000 gallons. This compares with the current market value of $7.30/kg.

-----Electrolysis

.--Description. As it is applied to hazardous waste separation, electrolysis involves reducing or oxidizing dissolved species at the surface of conductive electrodes. For example, metal ions may be reduced to metals at a negative electrode, as is done in the copper industry to rejuvenate pickling baths. In this case, an electric potential is applied to a 2-7% copper solution thereby generating oxygen and hydrogen ions at the anode and plating the cathode. The recovered metal is valuable in itself, and the ions keep the pickling solution at a desirably low pH.

Pumping and stirring are also utilized in recovering metals from dilute Streams, particularly those of concentrations less then 1%. Stirring the solution so that the electrolyte is quickly circulated through slits in the electrodes will Supply them with metal ions at a sufficiently rapid rate for recovery. Pumping the electrolyte over a rotating cylindrical cathode will deposit the metal on the cathode, from which it can be mechanically stripped and reused. The voltage potential at which an electrochemical reaction takes place is dependent on limits set by diffusion, catalytic reactions, and cell resistance. These limitations are termed overpotentials and are functions of several operating conditions such as current, temperature, and pressure.

4-26 At high current densities the greatest share of losses are caused by diffusion overpotentials, which occur mainly when concentration gradients caused by the slow- step in the reaction form in the cell. Stirring of the electrolytic waste solution is used to mitigate concentration effects by dispersing the reacting species.

Applications. Electrolysis is used widely for industrial chemical applications and has uses as well in metal refining, chlorine-caustic production, molten salt bath electrometal 1 urgy, el ectrowinn ing , and el ectropl ating . Electrofl otation , a simi 1 ar technology in which electrolytically generated bubbles are used to separate oi1- water mixtures, is used to treat steel -roll ing mil1 wastes.

Waste water pollutants from electroplating operations include cyanide, oil, grease, and such toxic metals as cadmium, copper, chromium, nickel, lead, and zinc. These substances can be controlled with a wide variety of management systems. Electroly- sis is a waste management technique which can effectively remove most metals (i.e., silver, copper, zinc) from diluted solution, although nickel cannot be recovered due to its low standard potential and the high stability constants of its cyanide complexes. Some manufacturers of electrolytic equipment claim that dissolved species such as cyanide are oxidized at the anode during electrolytic recovery of metals. Nevertheless, an analysis conducted by Covofinish Co., Inc. of North Scituate , Rhode Is1and concl uded that chemical methods of cyanide destruction must be used in conjunction with electrolysis in order to satisfactorily destroy the cyanide present in solution (4).- The choice of waste management must therefore be chosen carefully.

Until recently the most commonly used waste treatment system for electroplating wastes has involved separating the metals from waste waters through chemical precipitation, flocculation, and sedimentation (Figure 4-6). However, this procedure generates poi sonous sludges comprised of precipitated hydroxides or carbonates, and the hazardous waste si tes used for dumping became subject to regulations that went into effect in May 1982 under the RCRA Amendments. The new federal legislation lowered the acceptable contamination levels in wastewaters, and further compl icated construction, monitoring, and record keeping procedures such that disposal costs have increased significantly. In addition, plating chemicals and process water have become more expensive. It should also be noted that the Electroplating Pretreatment Standards that took effect in 1984 are substantially lower for plants discharging less than 10,000 gallons per day into POTWs, further encouraging dischargers to recover wastes and conserve water.

4-27 Cyanide waste Fq Caustic 1 Pol jmel I 9 I Acid 1

+discharge

Cyanide oxidation Neutralization Flocculation precipitation Clarification

Chrome waste Q XIv! r5 - 1 3- Chrome reduction

Actd/alkali waste :+ Sludge thickening Averaging

to approved disposal I Filtration

Figure 4-6. Conventional Wastewater Treatment System for Electrop ating Source: Ref. 5, p. 15

4-28 The combination of these factors has led to the development and more widespread use of reduction and management techniques which decrease the amount of toxic sludges produced. There are, for instance, several recovery methods that have been proven effective for on-si te and in-process recovery including elecrodialysis, el ectroly- sis, evaporation, ion exchange, reverse osmosis, and ultrafiltration. The advantages and disadvantages of each technology are outlined in Table 4-13.

Electrolytic recovery of metals from dilute solutions has also proven to be an effective and economical recovery technique. Allied Metal Finishing of Baltimore, Maryland is presently using the technique to recycle cadmium. As part of their reduction scheme the company lowered the water used for finishing processes from 127,000 to 66,000 gallons per day. Next, they installed the electrolytic recovery system diagrammed in Figure 4-7. As shown in the flowchart, process rinse water is first pumped through a filter to remove particulates. When the solution enters the electrochemical reactor, the cadmium is plated onto a carbon fiber cathode from which it is returned to the plating bath by either reversing the current or rinsing the cathode with a stripping solution.

End-of-pi pe el ectrolytic (a1so known as electrochemical ) treatment is a1 so available. Andco Environmental Process of Amherst, New York has installed nearly 100 units that recover metal s from wastewaters with a patented electrochemical process (8).-

In Andco's electrochemical treatment process, consumable iron electrodes in the presence of an electric current generate ferrous ions which then serve to copreci- pitate heavy metals from pol 1 uted wastewater. The electrodes are consumed in generating the ferrous ions; heavy metals are not plated onto the electrodes. When chromium is present in solution, the reaction proceeds as follows:

3Fet2 + Cr04-2 + 4H20 2 3Fe+3 t Crt3 + 80H- .

The ferric hydroxide and metal hydroxides which result are precipitated in a cl ari fier and are dewatered in a filter press (Figure 4-8).

Chromium is the only metal which undergoes chemical reduction; other metals such as copper, tin, lead, nickel, and zinc are coprecipitated with the ferric hydroxides. The sludge produced by the process has been formally delisted in the Federal Register and is therefore considered non-hazardous by the EPA.

4-29 Table 4-13

IN-PROCESS RECOVERY METHODS FOR METAL, PLATING WASTEWATER

'l~CllNI~)Lll;/ APPLICATION ADVANTAC li S I11 --- SADVANTAGES Electrodialysis - Achieves higher concentratio - Feed must be filtered Au. Fe. Ag. Zn. Sn- than reverse osmosis or ion - Membrane sensitive to flow Pb, Watts Ni, NiSB. exchange distribution. pH and suspende~ NIB. CuCN. CdCN - Energy efficient sol ids - Organics not concentrated - Equipment usee multi-cell - Inorganlc salts transport at 1 stacks. incurs leakage different rates minimizes - Chemical adjustment of re- return of unvanted inorganic covered material - Nev technology - membrane lifi uncertain

Electrolytic Metal - Recovers only metals - Solution concentration must bq Recovery - Results in saldh, non- monitored - Fumes may form and may requirt CuCN. Au. Pb, Ag, Zr hazardous product Cu pre-etch, Cu finr - Energy efficient, leas than hood scrubbing system Solution heating encouraged tt etch, acid Cu, Sn-Pt lOC/lb-Cu - maximize efficiency SnAlk, SnSO , - Low maintenance Watts Ni. CkN Elec- - Eliminates metal ion and troiess Cu, Electro- impurity build-up leas Ni

Evaporators - Established and proven tech- - Energy intensive Acid Cu. Sn-Pb, Au. nology, very reliable - Most evaporators designed for Fe, Pb. Watts Ni. - Simple to operate steam heating - Widely applicable NiSB. NiB. Zn, CuCN. - Multi-stage countercurrent Ag. CdCN. Cr etch, - Can exceed bath concentratioi rinsing essential Cr - Returns bath and impurities - Additional treatment may be needed to control impurities - Hay require pH control

Ion Exchange - Low energy demands - Requires tight operation and - Handles dilute feed Au. Cr etch, AgCN, maintenance - equipment com- - Returns metal as metal salt Cr. Sn. Zn. Cu pre- plex solution etch, Cu final etch, - Limited concentration ability acid Cu. Watts Ni. - Hay require evaporation to NiSB. NIB increase concentration - Excess regenerate required: 3-SX stoichiometric quantity, :. waste - Feed concentration must be closely monitored

Reverse Osmosis . Achieves aodest concentration - Limited concentration range of Watts Ni. NiSB, NIB. ' Small floor space require- ope rat ion Zn menta - Fouling of membranes due to Less energy intensive than feeds high in suspended solids evaporation feed filtration essential - Can return valuable additive1 - Membrane sensitive to pH - Some materials fractionally rejected

Ultrafiltration . Lov operating costs - Limited temperature range of . Very compact Cd. Cr, Cu. Au. Fe. operation Pb, Ni. Ag. Sn. Zn - Fouling of membranes

Source: Ref. 6, p. 4

4-30 Makeup water

_____Workpiece ___ Recovery rinse____- ___ -+ I- - -I I

Plating bath Rinse tanks

To wastewz 3r treatment

Clean water

Electro- Filter w Chemical I - I reactor

Figure 4-7. Electrolytic Recovery System

Source: Ref. 5, p. 22

4-31 00

c > POLYMER T R EAT E D EFFLUENT

SLUDGE FILTER :AL PUMP PRESS I' '1ll PROCESS FLOW DIAGRAM ANDCO HEAVY METAL REMOVAL PROCESS

Figure 4-8. Process Flow Diagram - Andco Heavy Metal Removal Process

Source: Ref. 9, p. 2

4-32 A program that has emerged from the push for waste recovery and water conservation is the Pollution Prevention Pays Program, organized by the North Carolina Department of Natural Resources and Community Devel opment. They advise electropl aters to use drag-out recovery tanks. In this system approximately 50% of the film of plating chemicals (i.e., "drag-out") that is rinsed from parts during the metal finishing process is captured in each tank before reaching the running rinse (Figure 4-9). The concentrated solution can then either be evaporated and recycled to the process tank; treated on-site; or sent off-site for reuse, treatment, or disposal. Table 4- 14 lists the applications, costs, and estimated payback periods for the various drag-out reduction and solution management techniques available for the treatment of finishing wastes.

Energy and Cost. In general, electrical energy needs make up between 10 and 35% of the total direct operating costs of electrolytic systems. The electrolysis of dilute metal streams is a more costly method due to lower efficiencies; Andco's electrochemical wastewater treatment process, for instance, requires about 5 kWh per pound of heavy metal removed. Operating costs are approximately one dollar per pound, and capital costs depend on the concentration of heavy metals and the quantity of wastewater treated. The cost of the basic equipment is slightly more than that for chemical precipitation.

Electrophoresi s

Description. Electrophoresis may be used to separate almost any type of charged particulate from either aqueous or organic media, including slurries, aqueous or non-aqueous 1 iquids, and col loidal sol utions. In the process, feed material s are placed between layers of membranes contained in a cell and are then subjected to a DC potential. Opposi tely-charged electrodes situated at each end of the cell attract the particles, and dialyzing membranes which permit only small ions and water to pass prevent further movement (Figure 4-10). Electrophoresis differs from electrodialysis in that the membranes pass anions and cations.

Any form of electrical ly-charged particulates, whether 1 iving cells, inert material , or complex macromolecules, may be concentrated by this process. Interestingly, the source of the charge on the particles is not always apparent, though two possible sources are partial ionization and sorption of ions onto the suspended material.

Higher voltages may be used with organic media rather than with aqueous solutions due to the lack of secondary reactions produced. There are, however, a number of potential drawbacks associated with the use of organic solvents, including toxicity,

4-33 Plating Recovery Final bath rinse rinse

waste treatment

Figure 4-9. Recovery with a Drag-out Tank

Source: Ref. 7, p. 8

4-34 Table 4-14

TYPICAL COSTS FOR DRAG-OUT REDUCTION AND DRAG-OUT SOLUTION MANAGEMENT

TECHNIQLE APPLICATION CAPITAL COSTS OPERATING COSTS COST SAVINGS PAY BACK

Drag-out reduction

-Drip bar Copper $100/tank min ima 1 $600/yr 8 weeks

-PVC drain board Chrome $25/trnk minimal $450/yr 2 weeks

-Proper racking Zinc $0 minimal S600Iyr _--_ -Uinimize metal concentration Nickel $0 minimal $700/yr ----

-Drag-out recovery Chrome S500lcank minimal $4.700/yr 6 weeks

Solution management

-Ion exchange Nickel $78,000 $3,20O/yr $I .900/yr 5 years

-Reverse Osmosis Nickel $62.000 minimal $40.000/yr 19 months

-Evaporation Chrome and Nickel $2.500 NIA NIA 6 weeks-6months

-Sludge recovery/ waste exchange Copper $50,000 NlA 14 weeks

-Drag-out recovery Nickel $1,000 minipal 11 weeks

NIA: not available

Source: Ref. 6, p. 5

4-35 A B &-

Figure 4-10. Basic Electrophoretic Reactor

Collecting plates M sequester all migrating particles, such as negatively charged particles A, but do not collect the neutral particles B. Source: Ref. 2, p. 436

4-36 recovery problems , and cost. For instance, higher (therefore, more costly) voltages may be necessary with organic media due to the lack of secondary reactions and the production of oxygen and hydrogen inherent in the electrolysis of water.

Electrodecantation, also known as electrogravitation, employs the density gradients formed on either side of the electrophoretic membrane to concentrate the suspended particles. The purified solution that has passed through the membrane is less dense and may be collected at the top of the membrane. The concentrated solution is collected at the bottom. Commercial applications of the process have been the creaming of rubber latex and the concentration of Teflon latex.

Hydraul ic pressure produced by pumps is used in forced-flow electrophoresis systems to control the movement of liquid between compartments. The system has been used to fractionate animal sera for veterinary vaccines.

"- "- Applications. Proposed commercial applications include reclamation of industrial wastes , separation of emulsions , color removal , and deposition of ceramics , metals , cements, and high polymers (i.e., rubber and paints).

Energy and Cost. A typical electrophoretic wastewater treatment system requires approximately 7kWh/100 gal , with flow rates ranging between 0.3 and 0.7 /m2 of membrane surface. Aqueous solutions and organic solvents with low conductivity requi re 1 ess power than el ectrodialysi s and electroplating techniques which use more energy per unit weight of material removed.

The foltage range required for a non-aqueous system varies from a few hundred to over a thousand volts, whereas aqueous systems need only about 15 volts. Current dens ties are approximately 2 ma/m2 of membrane surface. cost data have not been fully quantified due to the general lack of experience with this process. However, overall costs should be comparatively less than with electrodialysis since the cost of the membranes and filters used in electrophoresis is much less than that for ion exchange membranes.

Filtration Techno1 ogies

Description. Filtration is a purification technique that employs mechanical straining, gravitational settling, diffusion, interception, or inertial impaction to separate suspended particles from solutions. Pretreatment methods are sometimes used to precipitate, flocculate, and/or settle the waste material before filtering

4-37 of the contaminated liquid. In cases where it is not possible to increase particle size by flocculation, filters with smaller pore sizes can be used. The chart in Figure 4-11 depicts the types of separation processes in relation to the types and sizes of particles which they can filter.

Applications. Particles larger than about a micrometer in diameter can be sieved with particle filters such as granular media filters, rotary drum vacuum filters, and filter presses. There are a large number of these devices used commercially for municipal and industrial waste management, especially in the area of sludge dewatering. In the area of waste treatment they are generally used in conjunction with precipitation, flocculation, and/or sedimentation. Some of the hazardous materials that are typically removed from wastewaters using this method are cadmium, arsenic, mercury, lead, and chromium.

Energy and Cost. Energy requirements for fi 1 tration include backwash pumping , surface wash pumping, coagulant feed, and return of backwash wastewater for additional processing. Energy consumption varies with a number of factors including filter medium, wastewater flow rate, and solids loading on the filter. For instance, frequent backwashing is required with greater sol ids loadings, and hence more energy is required (10).-

Energy and cost data for the treatment technologies suitable for particulate and dissolved solids removal are presented in the treatment technology sections which cover reverse osmosis, ion exchange, ultrafiltration, and electrodialysis. For information concerning sludge dewatering technologies refer to "State-of-the-Art Survey of Mechanical Dewatering Systems" (11).-

Freeze Crystal 1i zation

Description. The freeze crystallization process is based on the physical principle that those ice crystals formed during the freezing of aqueous liquids are for the most part pure water. Selected contaminants are thus concentrated when the ice crystals are separated from the feed solution. Once this process has been completed, the frozen water is washed, melted, and either discarded to sewers or recycled for further use. The basic process is shown in Figure 4-12.

Applications. Two companies were identified which market freeze crystallization systems for hazardous waste water reduction: CBI Industries, Inc. of Plainfield, Illinios, and Heist Engineering Corporation of Walnut Creek, California. Freezing systems have also been used for sea water desalting; air conditioning and load

4-38 Figure 4-11. Particle Size Ranges Applicable to Various Filtration Processes

4-39 4

m n a, c, v)

4-40 management; concentration of fruit juices; and for processing non-hazardous waste water streams, for instance, the water recovered from mining operations or cooling tower blowdown.

Heist Engineering has devel oped and marketed freezing systems for hazardous waste reclamation and for concentrating wastes prior to incineration. Liquid wastes from these applications can be concentrated in the range of 20:l to 0:l using the secondary refrigeration process shown in Figure 4-13. In this manner, separator 2 can be another freeze process or some other process, such as a filter, which serves to further separate the water from the waste.

The indirect freeze process as developed by CBI Industries is shown in Figure 4-14 in a cooling tower blowdown application. The process also has uses for volume reduction of aqueous hazardous waste produced by many industries, particulary aqueous solutions containing metals , reactive ions, and/or organics.

Energy and Cost. Cost estimates of Heist Engineering's secondary refrigerant freeze system are on the order of $0.10 to $0.30 per gallon of liquid waste treated for a 600-gal/hr system. Electricity needs make up approximately 5% of the total cost.

The energy consumption of CBI's indirect freeze process for concentrating wastewater is about 6kWh per 100 gallons of water removed. This estimate varies depending on several factors, including the type of wastewater and the dissolved solids concentration.

High Energy Electron Treatment

Destruction of toxic chemicals by electron treatment was studied at MIT's High Voltage Research Laboratory. Water-di ssolved PCBs and Monuron, a persistent herbicide of the urea type, were irradiated with the Van De Graff accelerator. Although the process successfully treated the toxic organics, the construction of an industrial-size system was found unattractive due to high costs. Also, the consequences of irradiating an unpure solution are not known; the hazardous materials were irradiated in nearly pure water (13,E).

4-41 a 0 sI- 2 W cn

r- oe a5 2 W v)

J a

4-42 WASH WATER PRIMARY SECONDARY I CONDENSER I

PRODUCT SECONADRY COMPRESSOR FEED t <*RECYCLE BRINE I 1 1s RECEWER BRINE 4 REJECT

P I P 2 RECEIVER W FREEZE SEPARATOR EXCHANGER - Y . SOUD PREClPlTATE SEPARATOR CONCENTRATOR -

Figure 4-14. CBI Indirect Freeze Blowdown Concentration System Source: Ref. 3, p. 3-1

'I 'I High-Temperature--- F1 uid-Wall Reactor- Description. The advanced electric reactor (AER) is a new technology being developed by the J.M. Huber Corporation, and is capable of destroying any solid, _- liquid, or gaseous hazardous waste. It is especially well suited, however, for the

destruction of contaminated soil and liquid wastes which are too low in heat content ~ to incinerate economically.

During operation, the contaminated material is gravity fed into the top of the AER. The device is shown pictorally and schematically in Figures 4-15 and 4-16, respectively. A gaseous blanket of nitrogen gas, flowing radially inward through the proprietary porous core wall , creates a tunnel in the reactor core through which the wastes fall.

Six high-impedance carbon electrodes, located between the graphite core and the outer vessel , are used to heat the core wall to incandescence (typically 2,300" - 2,400"C). The intense radiation, in the near infrared, rapidly pyrolizes the wastes which pass through the AER. The reactor can be operated in oxidative and neutral atmospheres, and at moderate pressures or partial vacuum. Heat balance calculations estimate heating rates in the range of 50,OOO"C per second for the process. Radiative power densities of approximately 1,860,000 W/m2 are produced.

The reaction products of soil-borne PCB destruction are HC1, C12, H2, elemental carbon, and a granular, free-flowing sol id-derived waste. The systems used to capture these products are shown schematically in Figure 4-17.

After exiting the AEK, the stream of material is sent through two post-reactor treatment zones (PRTZs) which cool the gas to less than 1000°F and provide additional high-temperature gaseous residence time. The solids are then collected in a bin which is sealed to the atmosphere. Particles suspended in the gas are removed first by a cyclone, then by a baghouse system which removes fines particulates. Chlorine is removed from the emissions with an aqueous caustic scrubber and any residual organics and chlorine are removed by passing the process gas through activated carbon beds. Finally, the gas, composed almost entirely of nitrogen, is emitted to the atmosphere.

The J.M. Huber Corporation considers the rotary kiln incinerator to be the largest competitor of the AER; the two treatment methods will be compared in the following paragraphs.

4-44 AER OPEIWTION

The AER anprocess sohd. hqud. or gaseous feed streams at temperatures approachmg 5ooo"F. In tlus enwonment. mst known sohds subheor melt and chermcal reamons m at rates thousands of tunes faster than m conven- bond reactors Feedstock sohds must be in the form of free-llowmgpowders and hquds as dsaete droplets

Feed s~mheated by rhermd rad" born rexnon cbmkwalls

Figure 4-15. AER Operations

Source: Ref. 15, p. 2

4-45 I I E I 1. Expansion Bellows I c 2. Power Feedthrough Cooling Manifold 7 3. Power Clamp 4. Power 1 Feedthrough Assembly 1 -5. Radiation Deflector IC--_I -7. Electrode Connector

II -9. Porous Core 10. Radiation Y 13. Radiometer Port 11. Heat Shield I

12. Cooling Jacket - ‘14. Blanket Gas Inlet (Typical)

Figure 4-16. Vertical Cross-Section of Advanced Electric Reactor

Source: Ref. 16, p. 3-2

4-46 Air Tight Hopper 0For Feed

Metered Screw Feeder

N__1-1-_ Reactor

Slide Valve-

Fan Baahouse L

I 1I Stack

Waste Bin

Figure 4-17. Process Configuration for the Trial Burn

Source: Ref. 17, p. 9

4-47 The high-temperature fluid-wall process can be categorized as a pyrolytic electrotechnology and, as such, has several advantages over incineration. In pyrolytic systems the process products are the elemental precursers of the molecule, i.e., carbon, hydrogen, and chlorine (if chlorinated wastes are destroyed). Stack emissions are thus typically free of organics at limits of detection. In a combustion process, on the other hand, traces of several hundred organic compounds are typically found in the flue gases due to incomplete combustion, either because of flame quenching near a cold surface or incomplete mixing inside the incinerator. Additionally, NOx emissions are produced during combustion processes, and these must fall below concentration standards as part of the air pollution permit process. Coping with NOx emissions adds cost and complexity to the process.

AERs are less sensitive than the average incineration processes to the normal and abnormal process control variations which result from the long residence time and high temperatures employed. Also, such process upsets as the rapid temperature drop associated with a power outage in an incinerator while hazardous materials are still in the combustion zone will not occur in an AER. Huber claims that the design of the reactor is fail-safe since more than an hour is needed to cool the AER core below effective pyrolysis temperatures.

In order to keep destruction efficiencies at acceptable levels during oxidative incineration, the temperature in the secondary combustion chamber must be held at 1200°C plus or minus 100°C for at least 3 seconds. Incineration is subject to efficiency variations caused by 1 imitations of process control and measurement equipment, variations in fuel properties, and caking and fouling on burner surfaces. Consequently, tight process control is needed to ensure that the process will be held within these and other limits.

Another advantage of the AER process is associated with lower gas flow velocities. The AER can use carbon traps to remove particulates from effluent gases, whereas they are uneconomical for the larger gas flows inherent in incineration processes. In addition, the AER can be equipped with gas scrubbers, bag filters, and other gas treatment unit operations as needed to provide redundant treatment of stack emissions and backup for emergencies.

With Huber's technology, however, there is the need to process the feed material to -35 mesh, whereas 3-inch chunks are acceptable for incineration. Huber claims that soil pretreatment costs are no more than 10% greater than for other thermal treatment techno1 ogies.

4-48 Applications. The AER system has been authorized to treat every RCRA-listed, non- nuclear hazardous waste although, as with all other treatment processes, the system must be permitted for each site at which it is used. It produces destruction efficiencies of over 99.9999%, which exceeds all current and projected governmental standards. EPA granted its first commercial permit for treating dioxine waste to Huber after they successfully demonstrated their process in November 1984 at Times Beach, Missouri.

The most applicable locations for on-site treatment with the AER should have the need for high destruction efficiencies together with the need to treat large volumes of wastes. Recommendations for the evaluation of the AER were made by the Office of Techno1 ogy Assessment in the detoxification of 500,000 tons of dioxine-contaminated soil in Missouri and as a possible technique to clean up Love Canal in New York state.

Other potential applications for the process include metal refining operations; coal gasification; vitrification of inorganic hazardous wastes and low-level nuclear wastes; and production of powdered refractories, glass fibers, fillers, rock wool, and other ceramic products.

Several commercial in-process applications are being investigated with the Department of Defense and several companies with PCB contamination problems. However, there are no operating commercial systems at this time.

Energy and Cost. Energy requirements vary with the moisture content of the wastes and the temperature of the reaction. The reactor itself operates with 480-V, 3- phase power with a maximum demand of 5-MW. For contaminated soil electricity needs are about 1,100 kWhIton (1,877 Btullb). The cost equivalent for the energy is $55/ton of soil based on $O.OS/kWh.

Total costs range from $500 to $1200 per ton of soil processed. These costs are attributable to the following factors:

Ma in tenance 12% Labor 7% Electrical energy 29% Depreci ati on 18% Other (permitting, setup, post-treatment, landscaping,etc.) -35% 100%

Unit costs for a soiltreating system are estimated at $4 million.

4-49 Incineration

Description. Incineration is a highly-devel oped thermal treatment technology and is used worldwide for hazardous waste managment. NATO estimates of the fraction of hazardous wastes that are incinerated in several countries are presented in Table 4- 15. Although the values given for the total volume of waste may not be precise, the pattern of greater use of incineration in Europe is evident. Only recently have incinerator manufacturers begun developing market strategies in the U.S. , primarily due to tougher landfill regulations than in the past.

Incineration is synonymous with combustion and involves the destruction of toxic wastes through thermal oxidation. Brief descriptions of several basic incinerator designs are listed in Table 4-16. Rotary kilns and liquid injection are the systems most commonly used for hazardous waste destruction. The Mitre Corporation under contract to the EPA compiled data in 1981 from existing incineration facilities and manufacturers to create a profile of hazardous waste incineration in the U.S. Operating parameters for four types of incinerators are presented in Table 4-17.

The advantages of incineration are similar to those of other thermal techniques. Incineration offers a substitute for landfilling, thereby alleviating the risks of groundwater contamination, gaseous emissions , and the spontaneous ignition of waste. Although the products of incineration--bottom ash, fly ash, and scrubber sludge--may themselves be a problem to dispose of safely.

A typical incineration system is diagrammed in Figure 4-18. The basic design consists of a waste feeding system reaction chamber and emission control systems, such as scrubbers and electrostatic precipitators. EPA has set the following performance standards for hazardous waste incineration (l-):

0 A 99.99% destruction and removal efficiency (DRE) standard for each principal organic hazardous constituent (POHC) designated in the waste feed. (This is the most difficult part of the standard to meet.) The DRE is calculated by the following mass balance formula:

DRE = (1 - Wout/Win) x 100% , where :

Win = the mass feed rate of 1 POHC in the waste stream going into the incinerator, and

Wout = the mass-emission rate of the same POHC in the exhaust prior to release to the atmosphere.

4-50 Table 4-15

VOLUME OF HAZARDOUS WASTE PRODUCED AND FRACTION INCINERATED IN INDIVIDUAL COUNTRIES

Total volume of Port ion inc inera ted Country waste (tlyr) 1) (t/yr) (%)

France 2,000,000 400, 0002 20

Germany 3,500,000 540 ,0003 16 Great Britain 3,000,000 150 - 200,0004 5 - 6.6 Nether1ands 5 420,000 210,000 50

Nor way 200,000 50,0006 25

United States 35,000,000 1,960,000 5.67

Remarks :

1. including waste oils etc.

2. not including on-site incineration

3. not including .appr. 320,000 t/yr which are co- ncinerated in household waste incineration plants

4. not including in-house (on-si te) incineration of about 600,000 t/a in 73 in-house plants of which substantially more than 50% is accounted for by the oil refineries and the 1t -gest c hem ic a 1 manu f act urers 5. including waste oil and substitute fuel including incineration at sea excluding biological sl udges excl udi ng on-si te treatment

6. including 50% of waste oil used as fuel substitute

7. another 9.7% are uncontrolled incineration (all figures being estimated)

Source: Ref. 43, p. 12.

4-51 Table 4-16

COMPARISON OF THERMAL TREATMENT TECHNOLOGIES

Advantaoes of deslon features Dlsadvanlaoes of deslon features Status for hazardous waste lreatment Cumntly avall.Wa Inclnoratw designs: Llquld lnjectlon Inclneratlon: Can be deslgned to burn a wlde range of Llmlted to destructlon of pumpable waste Estlmaled that 219 llquld lnjectlon purnpablewaste. Often used In conjunction (vlscoslty of less than 10,OOO SI). Usually lnclnerators are In servlce. maklng thls wlth other lnclnerator systems as a deslgned to bum speclflc waste streams. the most wldely used lnclnerator deslgn. secondary afterburner for combustlon of Smaller unlts sometlmes have problems volatlllzed constituents. Hot refractory wlth clogglng of lnjectlon nozzle. mlnlmlzes cool boundary layer at walls. HCI recovery possible. Rotary kllns: Can accommodate great varlety of waste Rotary kllns are expensive. Economy of scale Esllmated that 42 rotary kllns are In servlce feeds: sollds. sludges. Ilqulds. some bulk means re@onal locatlons. thus, waste under lnterlm status. Rotary klln deslgn Is waste contalned In flber dNmS. Rotatlon must be hauled. lncreaslng splll rlsks. often centerpiece of Integrated commarclal of combustlon chamber enhances mlxlng treatment facllltles. Flrst nonlnterim of waste by exposlng fresh surfaces for RCRA permlt for a rotary klln lnclnerator oxldatlon. (IT Corp.) Is currently under revlew. Cement kllns: Attracllve for destructlon of harder-to-burn Burnlng of chlorlnated waste llmlted by Cement kllns are currenlly In USB for waste waste, due to very hlgh resldence times. operatlng requlrements. and appears to d851NCtlOn. but exact number Is unknown. good mlxhg. and hlgh temperatures. Increase partlculate generatlon. Could Natlonal klln capacity Is estlmated at 41.5 Alkallne environment neutrallzes chlorlne. requlre retrofltllng of pollutlon control mllllon tonneslyr. Currently mostly equlpment and of lnstrumentatlon for nonhalogenated solvents are burned. monltorlng to brlng exlstlng facllltleS to comparable level. Ash may be hazardous resldual. Boilers (usually a IIquId lnjectlon deslgn): Energy value recovery. fuel conservatlon. Cool gas layer at walls result from heat Bollers are currently used for waste dlsposal. Avallabllity on sites of waste generators removal. Thls constrains deslgn to hlgh- Number of boller facllltles Is unknown, reduces spill risks during haullng. efflclency combustlon wlthln the flame quantlty of wasles combusted has been zone. Nozzle malntenance and waste feed roughly estimated at between 17.3 to 20 stablllty can be crltlcal. Where HCI Is mllllon tonneslyr. recovered, hlgh temperatures must be avolded. (High temperatures are good for DRE.) Metal parts corrode where halogenated waste are burned. Applkatlons of currently avsllable designs: Multiple hearth: Passage of waste onto progressively hotter Tlered hearths usually have some relatlvely Technolwy Is avallable; wldely used for hearths can provlde for long resldence cold spots whlch lnhlbll even and complete coal and munlclpal waste combustlon. tlmes for sludges. Design provldes good combustlon. Opportunlty for some gas to fuel efficiency. Able to handle wlde short clrcult and escape without adequate varlety of sludges. residence tlme. Not sultable for waste streams whlch produce fuslble ash when combusted. Unlts have hlgh malntenance requirements due to movlng parts In hlgh- temperature zone. Fluidized-bedlnclnerators: Turbulence of bed enhances unlform heat Llmlted capaclty In servlce. Large economy Estlmated that nlne fluldized-bed transfer and combustlon of waste. Mass of scale. lnclnerators are In servlce. Catalytlc bed. of bed Is large relative to the mass of may be developed. Injected waste. mhgthomul tmatnwnt tuhnolophrr Molten salt: Mdten salts act as catalysts and efflclent Commanld-xaleappllcatlons face potenllal Technology has been successful at pilot heat transfer medlum. Self-sustalnlng for problems wlth rqpmeratlon or dlsposal of plan1 scale, and is commercially available. some wastes. Reduces energy use and ashcontamlnaled salt. Not sultable tor reduces malntenance cosls. Unlls are hlgh iuh wastes. Chamber COVOslOn Can compact; potentlally portable. Mlnlmal slr be a problem. Avoldlng reactlon vessel pollutlon conlrd needs; some combustlon corrosion may Imply tradeoff wlth DRE. products. 0.0.. ash and acldlc gases are relalned In the melt.

Source: Ref. 18, pp. 163-164

4-52 Table 4-17

DESIGN PARAMETERS OF COMMONLY-USED INCINERATORS

No. of Units w/Available Capacity Average Median Popu1ationBreakdown rype Data Measurement Values Value Value No. Units Range Liquid Injection 50 x lo6 Btu/h** 0.125-130.0 21.5 8* 5 105-io6 24 1o6-io7 18 107- io8 3 1o8-io9 Liquid Injection 43 Ib/h 30-24,500 3,960 1,600* 15 1.OOo 10 1,001-2,Ooo 9 2,001-4,000 4 4,001-10,000 4 10,000-20.000 1 20,000 Fixed Hearth 4 x 106Btu/h 3-9 4.9' - 3 3-5 1 9 Fixed Hearth 48 lb/h 25-2.500 810* N.A. N.A. Rotary Kiln 34 x 106Btu/h 1-150 35.6 10.3* 7 5 7 5-9 6 10-40 8 40-60 4 60-100 2 100 Rotary Kiln 2 lbh 1,200-2,080 1,640 - - -

Fluidized Bed 5 x 10'Btuh 8.5-67 45.5, 50 1 8.5 2 10-50 2 67

'Value chosen aa mart reprmntative central value of che distribution. **Matof the liquid injmction data were wailable as Ibh. These valun were converted (0 10. Btuh by MITRE enRineen, since was(+compositiotu were approximately known. SI Conversion: Lg - Ib x 0.454. W - Btulh x 0.293

Source: Ref. 19, p. 52

4-53 WATER- BLENDING FUEL OIL SOLUBLE WATER- BATCH TANK TANK LlOUlDS INSOLUBLE LIQUIDS

LlOUlD WASTES FROM TANK CARS NERATO OR TRUCKS TURBINE AIR STACK NDENSE BOILER FEED WATER t A CON~ENSATE

1 1 I SOLID PASTY

P I t m P I SCRUBBER

1 -- -0SCAdBBCRL 101:11) PITS ~~STEAM 1- ASH SLAG TRANSPORT FOR ASH,-- SIAG - - TREAT 1.1 ENi SOLID GASTESFOR PASTY WASTE

STORAGE INCINERATION HEAT RECOVERY

Figure 4-18. Flow Sheet of a Typical Incineration Plant for Hazard0 us Wastes

Source: Ref. 20, p. 152

‘I ‘I Table 4-18

TYPES AND QUANTITIES OF U.S. INCINERATORS IN USE

A. Companies Offering Incinerators for Hazardous Waste: Offer 1 TY Pe Offer 2 or Total No. Only More Types co. 45 12 57 R. Hazardous Waste Incinerators in Service: No. Co. No. in Total, TY Pe Offering Service

Liquid Injection 23 219 64.0 Fixed Hearth 12 59 17.3 Rotary Kiln 17 42"-b 12.3 Fluidized Bed 9 9 2.6

~~ Multiple Hearth 2 7 2.0 Pulse Hearth 1 2 0.6 Rotary Hearth 1 2' 0.6 Salt Bath 2 0 - Induction Heating 1 0 - Reciprocating Grate -1 1 0.3 Infrared Heating 1 1' 0.3 Open Drum 1 0 - Unknown 2 -0 - 342 100.0%

'Includes five 1t.K. unita in construction. blncludesone oscillating kiln. 'One unit in construction.

-----

So,urce: Ref. 19, p. 51

4-55 0 Incinerators that emit more than 4 pounds of hydrogen chloride per hour must achieve a removal efficiency of at least 99%. (All commercial scrubbers tested by EPA have met this performance requirement .)

0 Incinerators cannot emit more than 180 mg of particulate matter per dry standard cubic meter of stack gas. This standard is intended to control the emissions of metals carried out in the exhaust gas on particulate matter. (Recent tests indicate that this standard may be more difficult to achieve than was earl ier thought.)

Incinerators that treat PCBs must meet the stricter 99.9999% DRE standard estabi shed under the Toxic Substances Control Act (TSCA).

Applications. The study done by Mitre found that 342 incinerators were operating, and had been manufactured by a total of 57 American and European companies. Table 4-18 lists the types of incinerators, the number put into hazardous waste service, and the number of manufacturers making each type.

Over half of the incinerators are the liquid injection type. These units can destroy the hazardous compounds in dilute 1 iquid wastes and liquids containing significant amounts of dissolved solids. Fixed hearths and rotary kilns are the next most common types of incinerators manufactured, and are designed to treat liquids, solids, and fumes.

New incineration technology is being developed by both U.S. and foreign companies as a means of minimizing landfilling in the U.S. Incineration is a common technology for hazardous waste management in Europe, and efforts are now being made by European companies to penetrate the U.S. market.

At-sea incineration is simply the incineration of wastes on special ly-designed ships, usually utilizing liquid injection technology. However, the technique is being faced with a growing list of complications. Plans to phase out the treatment method in Europe have already begun, largely due to high environmental risks. In the U.S. as well there is substantial controversy over its use even though a 1980 study coordinated by EPA concluded that chemical waste incineration at sea when performed aboard specially-designed and -equipped vessels is a technically efficient , environmentally acceptable, and cost-effective technology. Test burns conducted by the EPA involving PCBs, Agent Orange, and organic chloride waste confirmed the 99.99% DRE capability for liquid injection incineration at sea.

4-56 Those in favor of ocean disposal conclude that the marine environment has the capacity to assimilate hazardous constituents. In fact , regulations do not require incinerators at sea to have stack gas scrubbers because of the assumption that the sea and sea air can act as a buffer for emissions. Those opposed are not convinced of the innocuous nature of the technology.

About half of the companies marketing the fourteen types of incinerators available, have sold none in the U.S. This statistic reflects several concurrent events in the marketplace. First of all, it is indicative of the presence of new corporations hoping to get a niche in the growing market for incineration. The RCRA legislative changes are responsible for the predictions of a shift in the U.S. to greater use of incineration and other types of treatment technologies for waste streams.

Only three commercial incinerators presently running in the this country are permitted under TSCA to dispose of both PCB contaminated liquids and solids. The companies and locations are as follows: ENSCO in El Dorito, Arkansas; Rollins Environmental Services in Deer Park, Texas; and Chemical Waste Management in Chicago, I1linois.

With the ban on land disposal of PCBs, these incinerators are the only places in the U.S. where PCB contaminated waste can be disposed of, and there are but a half dozen or so permitted to burn RCRA-defined wastes.

Energy and Cost. Energy and cost vary with type of incinerator, waste type, feed rate, and the air pollution equipment needed. In addition, wastes with high heat contents require little if any added energy for combustion. As shown in Table 4-19, liquid wastes with high Btu values are the least expensive to incinerate, and in some cases incinerators are purchased by cement kilns expressly for the fuel recoverable with this method. Highly toxic refractory solids and drummed wastes, on the other hand, are much more difficult to destroy and are correspondingly more expensive to incinerate, A comparison between unit costs for treatment and incineration of various types of waste is presented in Table 4-20.

Incineration units can be fired with natural gas, fuel oil, and/or electricity. Electrically-run incinerators are discussed separately in this report under specific techno1 ogy sections (e.g. , Mol ten G1 ass Incineration). Hazardous waste incinerator vendors reported that over 65% of buyers requested incinerators with heat recovery

4-57 Table 4-19

COSTS CHARGED FOR INCINERATION AT COMMERCIAL ON-SITE FACILITIES

Type or- Form of Waste Form: Drummed

Liquids $53 - $400

Type: Relatively clean liquids $(0.05)a - $0.20/gal $(13)a - $53 high-Btu value

Liqui ds $0.20 - $0.90/gal $53 - $237 Solids, highly toxic liquids $1.50 - $3.00/gal $395 - $791

a Some cement kilns and light aggregate manufacturers are now paying for waste.

-- Source: Ref. 18, p. 196

4-58 Table 4-20

INCINERATION VS. TREATMENT: RANGE ESTIMATED POST-RCRA CHARGES FOR SELECTED WASTE TYPES

Costs per ton Incineration Treatment

Waste oils $94 $40 Paint SI udges 4 53 94 Nonchl orinated sol vents 94 61 Chlorinated solvents 206 161 Cyan ides 211 29 7

NOTE: Cost estimates are based on surveys of commercial treatment and incinerator facilities in the Great Lakes regions. Costs reported re- flect the surveyed industries estimates of their charges based on compl iance with RCRA regulatory requirements for Interim Status facilities. No specific information provided about type of process or incinerator used, or characteristics of waste residuals.

Source: Ref. 18, p. 197

4-59 systems. Quotes from manufacturers show that the lower limits of energy recovery at which the payback became acceptable span the range of 2 to 7 million Btu/h and 30 gal/h (19).

Infrared--- Furnace -Description.-- In the infrared (electric) furnace constructed by Shirco Infrared of Dallas, Texas, wastes are broken down with infrared radiation emitted by electric heating elements. The processing capabilities of the unit include incineration and pyrolysis of wastes as well as carbon regeneration. A schematic followed by a description of the system components is shown in Figure 4-19.

During processing, feed material is dropped onto a conveyer belt and leveled to a thickness of one inch by a roller. The thin layer of waste then continues through the furnace under the glare of infrared lamps strung from above. Combustion air is sent into the furnace in the direction opposite to that of the wastes. After passing through the drying and combustion zone the offgases are sent to a secondary chamber where they are burned at 2,400"F with propane to destroy any volatiles driven from the wastes during incineration.

The furnace itself is lined with an 'alumina-silica blanket which is relatively lightweight compared to other materials, such as refractory brick. The low density of the wall lining adds flexibility to the applications of the system by allowing it to remain under the 80,000-lb load limit required for mobile systems. Furthermore, the Shirco system has the advantage over most incinerators in that it is run below or at atmospheric pressure. The result is less particulate carryover into the secondary chamber and lower energy needs. Also, air scrubbing systems tend to be smaller due to reduced exhaust flow velocities.

Applications. Shi rco Infrared Systems has been a longstanding supplier of infrared furnaces for drying, pyrolysis, and combustion purposes; in the past 10 years 48 of these units have been sold around the world. A mobile plant is also available, and can be set up for demonstrations in as little as four hours assembly time. On-Site Incineration Systems, Inc. has been created by Shirco specifically to market the infrared hazardous waste incinerator.

Waste types treated by the system include creosote pit, in-plant chemical , and low- level radioactive wastes, as well as soils from several Superfund sites, such as dioxine-contaminated soil from Times Beach, Missouri. A more complete list of applications is presented in Table 4-21,

4-60 Nlwtmatlon depkts one of many posslble conffguratlom of a typlcal waste dlsposal system.

No bwrwrs arc requ~redai any pmnl In the process

Process Description

Conditioned waste material is fed to the furnace by means Discharge System 12 to a receptacle 13.A Blower 14 forces of a Waste Feed System 1. passes through the Rotary air through a Combustion Air Preheater 15 to extract energy Airlock 2. and onto a Metering Conveyor 3 There the mate- from the exhaust gases and enters the Discharge Module rial is spread and leveled in the Metering Section 4 before U. Exhaust gases exit the furnace through the exhaust entering the Incinerator Feed Module 5 The Incinerator duct 16 At this point. the gases may go to the Secondary Conveyor 6 moves the waste material through Fiber Blanket Process Chamber 17 to incinerate any combustibles re- 7 insulated Heating Modules 8 where it is brought to com- maining and on to a heat recovery device such as a Com- bustion temperature by Infrared Heating Elements 9 and bustion Air Preheater 15 or Waste Heat Boiler (not shown) gently turned by Rotary Rakes 10 Ash (or processed mate- Gases are then cooled and cleaned in the Scrubber 18 and rial) passes from the Discharge Module 11 into the Ash exhausted by a Blower 19 through the exhaust stack 20

Figure 4-19. Typical Waste Disposal System with an Infrared Furnace

Source: Shi rco Infrared Systems

4-61 Table 4-21

POTENTIAL APPLICATIONS OF AN IR FURNACE

I NC I NERAT I ON 1. Municipal waste treatment sludge (multiple applications) *

2. Pharmaceutical sludge from clarifiers and biological trea'tment containing 6000 ppm chlorides.

3. Sludge by-product from organo-phosphate pesticide production, with and without cellulose added.

4. Sulfite process paper mil1 sludge.

5. Tannery sludge to convert chromium to hexavalent state. Chromium content of sludge was less than 1%.

6. Clay-bearing paper mi1 1 sludge for recovery of bleaching clay.

7. Phenol-bearing sludge from Zesin manufacture, and sludge mixed with shredded fiber containers.

8. Abrasive paper, to a1 low recovery of abrasive particles,

9. Biological sludyes from chemical plant waste treatment (multiple applications). * 10. Metal machining sludges, for oil removal (multiple applications).

11. Animal waste/bedding from wildlife park quarantine faci 1 ity.

12. Simulated low-level radioactive waste, including plastic, paper, and wood* mixed with non-combustibles. Perfonned both incineration and pyrolysis. 13. Steel mi 11 tars/decanter sludges.

14. Harbor &edgings contaminated with waste chemicals.

15. Soi 1 contaminated with oils and waste chemicals.

16. Peanut-oi 1-bearing industrial process sludge.

17. Soils contaminated with 20 % creosote and 1 % pentacholophenol. Achieved destruction and removal efficiencies (DRE) of >99.9999 I.

18. Soil contaminated with 230 ppb of 2,3,7,8-TC00. Achieved destruction and removal efficiency of >99.999997 %, Particulate einssions measured at 0.001 gr/dscf. No dioxin found in residual soil to detection limit of 38 ppt.

19. Coal slurry sediment sludge.

* Resulted in sale of full-scale equipment

4-62 Tab1 e 4-21 (continued) FILTER MEDIA REGENERATION 1. Fungicide- 1 aden yranu 1ar carbon catalyst .

2. Granular carbon from zinc products manufacture.

3. Powdered carbon for corn syrup filtration (multiple applications).

4. "PACT" Material from oil refining process.

5. Granular carbon with adsorbed herbicide residues containing chlorides.

6. Extruded carbon for European potable water treatment appllcation.

7. Granular cdrbon for corn syrup filtration (multiple applications).

8. Extruded carbon for food processing application in Europe. *

9. Granular carbon for oil shale wastewater treatment application.

10. Bleaching clay from food processing application.

11. Granular carbon for filtration of drinking water (multiple applications) *

12. Diatomaceous earth from food processing application (multiple applications).

13. Granular carbon with adsorbed perchlorethylene.

THERMAL PROCESSING Produced carbon eroduct in inert atmosphere (less than 100 ppm 02) without stem addition.

2. Produced char material from bone chips.

3. Produced catalyst product from silica-based raw material.

4. Produced reduced iron pel lets from iron/carbon matrix material.

5. Regenerated silica pel let catalyst for removal of sulfur compounds.

6. Regenerated granular catalyst for removal of oryanic contaminants.

7. Pyrolyzed industrial sludges for char and condensible fuel gas production.

8. Dried mixed industrial sludges for oil removal.

9. Dried industrial sludge for improved performance of existing incinerator.

10. Pyrolyzed simulated low-level radioactive waste for investigation of P 1ut o n iu m rqc ove ry.

11. Pyrolyzed municipal sludye to rtabi 1 ize chromium-bearing compounds in the trivalent state.

12. Pyrolyzed scrap tires for oil recovery and filter carbon production.

Source: Shi rco Infrared Systems

4-63 Shirco hopes to get involved in clean-up of sites covered by the new Leaking Underground Storage Tank (LUST) program called for by Subtitle I of the November 1984 RCRA Amendments. They have plans to decontaminate soil at service station sites within a 24-hour period using a mobile infrared system.

~ The company also hopes to take part in the destruction of the more than 16 million tires thrown away annually, and the accumulation of tires in abandoned "tire mines" in the South. As a method of disposal, brief lab research has been done in order to determine the feasibility of a plan to recover the liquid condensate from organic chemicals driven up the exhaust stack during incineration.

-Energy and Cost. Energy requirements and mass balances for four treatment plant sizes are presented in Table 4-22.

Shirco states that wastes can be destroyed by mobile units for less than $llO/ton including overhead and equipment costs. Welsh further believes that disposal costs could fall below $100/ton for stationary infrared units where startup costs are amortized over a longer period of time.

-Ion Exchange Description. Ion exchange (IEX) involves the removal of ionic species from dilute aqueous waste streams. Contaminated liquid is passed through an ion exchange resin which removes the dissolved, principally inorganic material from the wastewater. When all of the active sites in the resin bed have been taken up, the exchanger is rinsed with a brine or acid solution to return it to its original effectiveness.

Applications. This a well-developed process presently used on a commercial scale to process wastewaters generated by petroleum refining, metal finishing, pickling liquor, chlor-a1 kali , and chemical processes involving cyanide, PCBs, inorganic acids, and cadmium. In general, the process is applicable for extracting dissolved salts from aqueous solutions which are free of suspended matter and oxidants.

Added research into finding specific applications of IEX for the treatment of leachate from landfills and various other liquid waste streams was recommended by the National Research Council in 1983.

4- 64 Table 4-22

COST*, ENERGY, MATERIAL, AND HEAT BALANCE ESTIMATES FOR SLUDGE INCINERATION IN AN INFRARED FURNACE Shirco, Inc.

...... -.-. /Uternate ...... 1A 1B 2A 2B 3A 38 . .5 Mwlld - - . - 15 Mwlld :. . -50 M@/d - . 1 Mwlld 20% 40% 20% 40% 20% 40% 40% Stream Solids Solids Sdidr Sdids Solids Sdidr Solids Furnace design Number of units 2 1 2 1 3 2 1 Overall width. ft 8.5 8.5 9.5 9.5 9.5 8.5 6 Overall length, ft 72 72 88 88 96 88 32 Belt area per furnace. ft' 382.6 382.6 560.5 560.5 616.8 479.5 94.5 Loadin rate, Ib wet solids/ ft'hr8 11.8 13.9 12.1 14.3 11.6 13.2 11.3 Sludge feed lb dv soliddhr 1.806 2.133 2.713 3,200 4.293 5.064 427 Heat value. MM Btulhr 13.91 13.9 1 20.89 20.89 33.06 33.06 2-79 Volatile content. % drv solids 77 65 77 65 77 65 65 Water, Ibhr 7.224 3,200 10.582 4.800 17.172 7.596 641 Heat value. MM BNhr 0.28 0.12 0.41 0.18 0.65 0.29 0.02 Supplemental power Electric infrared, kW 280.8 - 402.5 - 643.8 - - Heat value, MM Btuhr 0.96C - 1-37' - 1.- - - Combustion air Volume at 60'F. Ib/hr 17.736 24.786 26.676 37.184 42.161 58.044 4,962 Heat value, MM Btuhr 0.26 0.36 0.38 0.54 0.61 0.85 0.07 Ash Volume at 5OO*F, Ibhr 415 747 624 1.120 987 1.772 149 Heat value, MM Btuhr 0.10 0.18 0.16 0.28 0.24 0.44 0.04 Radiation Heat loss, MM BNhf 0.36 0.18 0.47 0.24 0.77 0.43 0.07 Furnace exhaust Volume, Ibhr 26,351d 29,372' 39.616d 44.0MC 62.628d 69,732' 5.880' Heat value, MM Btuhr 14.95 14.03 22.42 21.09 34.54 33.34 2.70 Boiler exhaust Heat value at 500-F. MM Btu/hr 13.00 8.53 19.49 12.79 31.33 20.23 1.71 Recoverable heat 100% efficiency, MM Btu/hr 1.95 5.50 2.93 8.30 3.21 13.11 0.99 Scrubber water feed Flow at 70'F. gal/min 397 201 584 314 1,049 498 mi Scrubber drain Flow. gal/min 390 196 606 306 1.081 485 196 Temperature, 'F 120 120 120 120 120 120 150 Gas exhaust Volume. Ibhr 29.538 35.811 39,616 53,838 54.744 85.186 7,183 Temperature, 'F 120 120 120 120 120 120 120 Heat balue. MM Btuhr 1.98 2.77 2.96 4.18 4.71 6.57 0.55 Total connected power Horwoower 22' 25 30' 40 50' 60 7 Total insraJledcort.Mh4 dollars 1.2 0.9 1.6 1.1 1.8 1.5 0.4 'All data supplied by Shirco. Inc. bUseable area of belt. CAutogeoous with combustion air preheated to 500-F. dAt 750.F. 'At 1200-F. 'Does nor include supplemental power requirements for infrared heaters. -- * SAIC estimates Source: Ref. 21, p. 196

4-65 Energy and Cost. Energy needs are minimal , consisting mainly of electricity for pumping. In addition capital costs are moderate, estimated at $200,000 to $350,000. As for operating costs, resin bed replacement makes up a substantial _- portion of this item, averaging $2-8/1000 gallons of liquid waste.

Microwave Discharge

~ Description. Microwave discharge is a type of process that falls in the general field of plasma chemistry since wastes are subjected to a plasma created by microwave radiation and contained in a low-pressure environment (

Applications. Lockheed Missiles & Space Co. of Sunnyvale, California investigated the microwave plasma decomposition of hazardous wastes and concluded that the process is not practical for this usage. It was recommended that all development work be terminated (22).-

Energy and Cost. The system constructed by Lockheed was capable of processing vapor and liquids at a feed rate of about 1.1 lb/hr. Energy needs at this rate were 4 to 5kW. Arthur D. Little's operating cost estimates for microwave discharge were $0.40 per pound of waste treated (1976 dollars) (2).

Molten Glass Incinerator

Description. Penberthy Electromelt International , Inc. has developed , and is currently constructing and selling, an electrically-heated glass furnace which they call the Pyro-Converter. Almost any waste can be detoxified with the method-- whether oil, sludge, chlor-organic, plating waste, water, paint waste, or lagoon mud. For example, the furnace oxidizes chloro-organics into C02, H20, and HC1 (scrubbed to CaC12) and vitrifies the remaining inorganics.

The system (Figure 4-20) contains a reactor filled with five tons of glass which is initially heated to a molten state (1300°F) with natural gas, after which it becomes conductive. Submerged metal electrodes can then be used to raise the surface temperature of the pool to 2450°F and maintain it there.

When a chlorinated organic compound is placed in one end of the tunnel it reacts with oxygen and water vapor to form carbon dioxide and hydrogen chloride. For example, when tetrachl orbenzene is the chlorine source, the reaction proceeds as f 01 1ows :

4- 66 The HC1 can be dispersed in water and sold for metal pickling or can be scrubbed with wet limestone scrubbers to produce calcium chloride for general chemical or ice-melting use. The gases leaving the scrubbers are sent through a Brink filter to remove particulates and mist, so that the only gases leaving the exhaust are carbon dioxide, nitrogen, oxygen, and water vapors; there is no steam plume. If any ashes are produced they are converted to glass, which can be sent to landfill or topped off to make products such as patio paving blocks.

Air jets within the furnace speed the reaction. A water wall is used to remove heat from the exhaust gases which are used for evaporation, for process steam, or in a gas-to-air heat exchanger to preheat the process air.

Applications. The Penbarthy product, trademarked Pyro-Converter, is rated at 1,000 pounds of wastes per hour and is available for demonstrations in Seattle, Washington. Although just one small reactor was sold four years ago which treats 60 pounds per hour, reactor sizes ranging from 50 to 10,000 pounds per hour can be constructed. The current operating reactor is treating transuranic wastes at a DOE facility in Miamisburg Ohio, run principally by Monsanto Chemical, Inc.

Penbarthy is currently exploring opportunities to host their reactor at EPA Superfund sites.

If the hazardous waste treated by the Pyro-Converter can meet the EPA definition of a feedstock, which is reprocessed into non-toxic glass and hydrochlorine, and therefore within the bounds of the plant, fewer regulations covering the process may need to be met. Also by treating wastes in-plant, future liability problems associated with continued accountability of wastes when handled off-site, may be avoided.

Energy and Cost. The energy requirements of the system depend on the heat content of the wastes. For materials of low fuel equivalent, power consumption falls in the range of 5500-6600 kWh/ton. Energetic materials need little, if any, electrical energy input. Capital costs are $1.4 million for installation, and operating costs are estimated at $90-100 per ton.

4- 67 CONTAMINATED

COOLING AND ASES-TO-AIR SCRUBBING EAT EXCHANGER

Figure 4-20. Dirt Purifier & Hazardous Waste Incinerator Source: Penberthy Electromel t International, Inc.

i1 ll P1 asma-Arc Heaters

Description. Plasma-arc heaters can be used for the destruction of gaseous, liquid, and solid toxic wastes by heating these materials to the point of thermal decomposition. In a plasma-arc heater system (Figure 4-21) a gas stream is passed through a rotating electric arc struck between a cathode and an anode. Due primarily to Joule heating, the gas temperature is raised to a level which can exceed 12,000"K ( 21,140"F).

In the arc heater, the species of the gas are dissociated and also undergo some degree of ionization, attaining a plasma state, These gases then exit the arc heater into the reaction chamber where reactants are added and the principle reactions take place. At the exit of the reaction chamber are the product collection and effluent treatment systems. There are two major advantages to using an electric arc as a source of heat:

1) Temperatures higher than normal combustion temperatures can be ob tai ned . 2) The gases used can be free of the products of combustion without having to use special high-temperature heat exchangers. The theoretical temperature limit of the electric arc is extremely high, though practical devices are limited to maximum temperatures of around 20,000"K. The arc can consist of virtually any mix of gaseous species, thus either a pure or a controlled processing environment can be used.

For purposes of toxic waste treatment, the gas passed through the arc can simply be air with the wastes added in the reaction chamber at the arc heater exit point. These wastes will be heated by contact with the hot air and be decomposed into simple molecules or, if sufficient energy has been added, into atoms. With organic wastes the expected products of the reactions will be solid carbon, hydrogen, water, and simple hydrocarbons such as methane (CH4) and acetylene (C2H2). For heavy metals, the plasma system could be used to concentrate the metal 1 ic compounds.

AJJ~ -ications. Plasma-arc systems have a1 ready been demonstrated at the experimental scale by both Pyrolysis Systems of Welland, Ontario and Plasma Energy Corporation of At1 anta, Georgia. Destruction efficiencies have exceeded 99.999999% for tests with PCBs, and DES greater than 99.99% have been obtained with tetrachloromethane.

Plasma Energy Corp. currently has a 50-kW bench-scale system running at 10 to 15- kW. They predict that it will be several years before reaching commercialization due to the time required for securing permits from EPA. Presently, they are talking

4-69 AC from mains

Figure 4-21. A Conceptual P1 asma Processing System

Source: Ref. 45, p. 1 - 2

4-70 to several Pennsylvania-based companies in an effort to interest them in using plasma arc-technology. The relevant industries have a need to both recover metal chips created when ingots are ground and to detoxify the resulting oily solids.

The company claims that their technology can treat all types of waste, including those from the chemical , glass, petroleum, and steel industries. They see the biggest markets for their technology with PCB-laden oil and municipal waste.

A major advantage inherent in any plasma system is that a mobile unit can be built for use at the site where hazardous materials are produced, thus avoiding transportation costs. A further side benefit of the technology is production of a glassy slag material which can be mixed with asphalt and used to pave roadways. Furthermore, fly ash is not produced. Since fly ash may soon become classified as a hazardous waste, and even now poses leachate problems, this fact could prove quite beneficial.

Pyrolysis Systems is presently testing with a commercial-scale mobile unit which can process any petrochemical fluid or chemical substance. A preliminary permit request has been made with EPA, as the destruction efficiency results from a series of tests on PCBs have sucessfully met EPA criteria.

A commercial plant has been built in Landskrona in southern Sweden in order to recover metals from fine-grained dust and waste from steel and metal fabricating industries, as well as from ore concentrates such as zinc, lead, nickel , iron chromium, and molybdenum. The project was put together by ScanDust AB and the plant was built by SKF Steel Engineering AB. The process is shown in Figure 4-22 and is designed to process 70,000 tonslyr.

In this plant the exhaust gases, comprised of approximately 75% carbon monoxide, 24% hydrogen, and 1% nitrogen, are cooled and cleaned with baghouses and a venturi scrubber system. The solid products of the process are slag and hot metal. ScanDust hopes to sell the slag to roadbuilders and the recovered metals directly to deal ers and customers.

Energy and Costs. The power levels in the plasma generators at the ScanDust AB plant range from 1- to 10-MW. The annual amount of energy recovered by the hot water boiler and other systems amounts to approximately 95 GWH. The efficiency, defined as the ratio of the heat content of the gas to the electric energy input, is

4-71 Waste Y oxides 7 pelletizing

Figure 4-22. P1 asmadust Process Flow Sheet

Source: Ref. 44, p. 65.

4-72 about 85%. The mobile incinerator developed by Pyrolysis Systems requires approximately 3/4kWh/kg of waste treated. Costs are $1 million per unit capital outlay, and $3-4/kg of waste processed.

Pyrolytic Incineration: Rotary Hearth and In-drum

Description.I_ Mid1 and-Ross Corporation has developed and marketed two pyrolytic incinerators: Pyrotherm(TM) for high-volume hazardous waste destruction, and Pyrobatch(TM) for in-drum thermal treatment. Both follow a two-step process (Figure 4-23), which is not uncommon among hazardous waste incineration systems. The first step separates the waste into 1) an inorganic, inert char containing salts, metals, and particulates, and 2) an organic gaseous fraction. The gas then undergoes another step by passing to the second chamber where its hazardous elements are combusted to complete the destruction of hazardous compounds. The gas may then be released either to the exhaust stack, a boiler, or another heat recovery device.

The Pyrotherm(TM) system shown in Figure 4-24 is composed of a rotary hearth furnace, a rich fume reactor, and a heat recovery device. In one 5 to 30 minute revolution of the furnace, the inorganics are retained in char form and the organics are volatized and sent to the fume reactor. The process can be used as a volume reduction technique since metals may be recovered from the char. Then, too, since the char is inert it can be disposed of at a non- hazardous landfill site.

The Pyrobatch(TM) system shown in Figure 4-25 is designed to treat drum-contained liquids or solids, or loose bulk waste. The unit can treat from 4 to 12 drums at a time, and after the wastes are pyrolized and incinerated the drums can be reused. The waste decontamination process requires 1 ittle operator attention , being primarily concerned with loading drums into the furnace, after which a programmable logic control system takes over to time and locate the materials. When the cycle has been completed the cooked drums are removed.

Applications. Both pyrolytic systems made by Midland-Ross Corp. can destroy any type of waste, whether solid, liquid, or gas. Approximately eight units have been sold to date, each of which was custom-designed to fit the needs of the user.

Midland-Ross claims that their systems satisfy EPA requirements for the destruction of RCRA-identified materials, although the responsibility of permitting is that of the product user. Midland maintains Thermal Systems Center laboratories in Toledo,

4-73 Figure 4-23. Two-step Pyrol i tic Incineration Process

Source: Mid1 and-Ross Corporation

4-74 Waste Heat Boiler

Combustion Air Blowe

Refractory Duct Work

Rotary Hearth Furnace

Figure 4-24. Pyrotherm System

Source: Mid1 and-Ross Corporation

4-75 4-76 Table 4-23 COMPARISON OF THERMAL TREATMENT TECHNOLOGIES

3. 0 Company and rum Operating Treatment knch-scab M nits nil Ca Primary 1n-siie Mcbile M Eleamlechnolog rednology Nam Location rWh/C Cost (Won) Rate commercial vrlt Permits Waste Form E Stationary PYROLYTIC hagaard Resean High terrp. fluid 0.4 Bench EAF dust Both lNClNERAllOf co. wall (HTFW) reactor

J. M. HuberCo Borger, Texa iTFW - t2" mre 5ooo 1.o $500- 1200 10 tons/yr. :OIllR?-3rCiaF 1 54.0 - TSCAfor PCB's AIP On Stationary diameter 50 ibJmin. - all RCRAwastes HTFW - 3' me It2 b Imin. Bench 1 AIP On Mobile diameter ldlard-ROsS Cor Toledo. Ohio 'yrothern-rotary m ._ 6lN-%WbSA Commercial ab ._ All on aationary hearth furnace Pyrcbatch. 3.5 - 1 m-6600bs/ Commercial 1.5-1.0 nom All drurruontalnedwastes On Stationary carbonom fum. batch -

Shirm Infrared Dallas. Texas Infrared furnace 13.000 ._ $110 mtolvdaym Commercial 48 ?CRA pedin Dallas All on MobiW Systems .dd mxxiin toga Stationary TSCA'S PeB oermil P I WLTENGLAS! v Penbarthy seam, wast 'ym -Convener 5.5 $90- 100 x). 25.m bs/ Commercial 2 $1.4 t interim statlls for All on Stationary U INCINERATION :lectromen Inrl il fUrMCe doxine

PLASMAARC Pyrolysis Systen Welland. Plasmaarc 0.75 S3Mx)-4000 Bench 1 $1 .o preliminaryrequest All On Mcbile TECHNOLOGY inc. )ntario Canad, furnace

Plasma Energ) Atlanta. Plasma arc 50 Bench t All On Mobile/ Cop. Georgia furnam Stationary

Scan Dust AB Landskrona. 1.a9 70,CCOtonslyr. Commeraal 1 Reavers metalsfrom we Off Stationary Sweden ancentrates 8 metal fabricating wastes

'waste must proms4to facial powder size bApproximatetotal nuhrd Pryotherm and Pyrobatchsystem sold For research only Ohio to perform pilot-scale tests for clients. Available services include identifying material hand1 ing requirements, specifying furnace operating parameters , and measuring effluent emissions and clean-up needs for the stack gas (if required). _- Energ2 and Costs. The incinerators are available for use with natural gas and #2 fuel oil, but can also be induction-heated with electric power. An electrically- powered unit rated at 600kW and requiring 0.5 to l.OkWh/kg of waste has been sold to the U.S. Army to destroy chemical warfare refuse. This particular design was requested because of problems encountered in control 1 ing the volatilization rate with the oil-fired burners on the previous system.

The pyrolytic unit offered the Army the desired added control while providing further advantages in speed and clean1 iness.

Unit costs for the Pyrobatch system are estimated at $0.5 million for a 4-drum module, and $1.0 million for a 12-drum module. Unit cost estimates for the Pyrobatch system and operating costs for either system were not available from Midland-Ross due to the variability of design for various applications.

A summary of the thermal treatment technologies which require substantial amounts of electrical energy is presented in Table 4-23.

----Ozonation -Description. Ozone is a powerful oxidizing agent capable of breaking down many types of compounds, including some types of hazardous wastes, and is a strong antiviral and anti-bacterial compound as well. Primarily, there are two advantages to using this system for waste treatment applications: 1) the absence of many of the environmental problems created by toxic ions introduced by other oxidization agents, such as chlorine; and 2) the generality of its oxidations.

Table 4-24 lists some toxic substances that have been destroyed by ozonation. Furthermore, the list grows longer when ozone is used in the presence of ultraviolet light since the light acts as a stimulant for the oxidation reactions responsible for decomposing waste constituents. The enhancement of oxidation and subsequent reduction in ozone demand greatly outweighs the expense of purchasing and operating the necessary ultraviolet 1 amps.

4-78 Table 4-24

COMPOUNDS REPORTED TO BE DECOMPOSABLE BY OZONATION

Detergents Pesticides Alkyl benzene sulfonate DDT Anionic Detergent a-BHC Non-ionic Detergent Dieldrin Malathion Methyl parathion Aldrin

Phenols Aromatic Hvdrocarbons 3, 4-Benzpyrene Phenol o-, m-, and p-cresols Pyrene Cathechol 1,2- Benzanthracene Xylenols 3,4-Benzfluoranthene 11,I 2-Benzfluoranthene Biphenyl Chlorinated Hvdrocarbons Chlorobenzenes

_cc Source: Ref. 2, p. 771

4-79 Ozone dosage is measured in pounds of ozone per pound of stream contaminant treated, and in ppm of ozone. By increasing the weight ratio or instantaneous dose of ozone the degree of oxidation can be increased, up to the chemical limits particular to each reaction.

Ozone is a form of oxygen (03) having marked oxidizing properties due to the number of free radicals, and is produced by the discharge of electricity through air or oxygen. To date, ultraviolet excitation and corona discharge are the only commercial methods used to generate ozone. In the latter method, air or oxygen is passed between two electrodes separated by a dielectric material (Figure 4-26) and a corona discharge is produced by a high voltage applied to the electrodes. About 4% of the oxygen passing through the discharge is converted to ozone.

Ultraviolet excitation produces much smaller quantities of ozone, on the order of ppm. Various electrochemical approaches to ozone creation which generate ozone at higher concentrations and have lower capital costs are now under development. OxyTech Inc. of Cupertino, California has invented such a procces. Their system produces a gas stream containing 35% by weight of ozone, which is then diluted to 20% for safety reasons. The Swiss have developed a similar method in which ozone is directly evolved into a stream of water from a porous, inert electrode in contact with a solid-polymer electrolyte. High current densities are possible with the Swiss process, although low ozone concentrations have resulted (23).

The production of higher concentrations of ozone allows the oxidation of wastes that in the past either could not be treated by other oxidants or were unresponsive to lower ozone concentrations. Other benefits of the electrochemical methods include smaller contacting equipment between the concentrated ozone and the waste streams, and elimination of the need for the air preparation systems required by corona discharge systems. In summary, the advantages of electrochemical ozone generators are increased ozone concentrations and lowered size and cost of systems.

Mjications.---- Ozone is generally useful for dilute aqueous streams in which the wastes to be treated are the only organics present. Organic solvents, slurries, and tars are not good candidates since ozone is a relatively non-selective oxidizing agent.

Large-scale ozone treatment of aqueous and gaseous streams using corona discharge generators is well developed. Uses include treatment of drinking water, municipal wastewater, and sewage sludge, as well as odor control. For example, there are over

4-80 OZONE GENERATOR CORONA

WATER~JACKET ELECTRODE OZONE

Figure 4-26. Corona Discharge Ozone Generator

Source: Ref. 24

4-81 forty sewage treatment plants in the U.S. using ozone for disinfection. Other applications at four different plants are: removal of suspended solids, flotation removal of biological oxygen demand (BOD) , sludge dewatering , and oxidation of organics prior to sand filtration and granulated activated carbon (GAC) adsorption.

__ Ozone is generally used in conjunction with other treatment techniques, although there is no general flowsheet for such management schemes because the chemical constituents in waste streams differ greatly between sites. Extensive pilot testing at individual sites is thus needed to determine whether or not ozone will be most useful in that particular appl ication. Information is a1 so not generally avai 1 able because a1 though ozone equipment manufacturers sell their generators for hazardous waste applications, they are hesitant to discuss equipment destinations for proprietary reasons.

However, it is apparent that research in this area is being conducted by Bollyky Associates, Inc. of Norwalk, Connecticut , who have installed a bench-scale ozone system to treat river water contaminated with nitrate and agricultural chemical run- off in Ottumwa, Iowa. Ozone pretreatment is used at this site in combination with ferric sulfate coagulation. They have also designed another small plant which includes a recycle process for spent, deionized water used in UV manufacturing. Furthermore, they have designed a pi1ot plant to remove organic complexants from nuclear wastewater at the Hanford operations in Rich1and, Washington.

Electrochemical generation is in the research stage. During 1986 Oxytech plans to develop small-scale prototypes with outputs of less than 1 pound per day, with plans to eventually manufacture and market the small systems. Future applications of the process are anticipated to incl ude treatment of cool ing tower water, deionized water systems, potable water, and swimming pool s.

The concentrated ozone streams obtained with electrochemical methods can also be applied to the treatment of cyanides, heavy metals, pesticides , chlorinated hydrocarbons, phenols, dye wastes, and more. However, no commercial installations which treat these wastes are currently operational.

- Energy and Cost. Energy requirements for a corona discharge generator producing less than 10 pounds of ozone per day are about 10kWh/lb of ozone. At higher production rates there is some economy of scale; for example, just 6kWh/lb are needed to produce 1001b/day.

4-82 Capital cost and operating cost data are presented in Table 4-25 for two separate wastewater treatment plants in the Upper Eagle Valley Sanitation District in Colorado. The Avon plant employs a unit process identical to that at Vail with the exception that ozone is used at Vail for disinfection, while chlorination followed by dechlorination with sulfur dioxide is used at Avon.

Table 4-26 lists Arthur D. Little's estimates for installation and operation of an ozone treatment system to remove phenol from a biologically treated oil refinery effluent (1976 dol 1 ars). The re1atively high operating cost of $0.48/1000 gallons is due partially to the low effluent standard to be met and the presence of other organic species in the water stream which exert ozone demand.

A similar study done for ozonation of a cyanide-containing plating waste produced an estimated capital cost of $50,000 and operating costs of $0.45/ 1000 gallons. The theoretical study was to reduce CN' from 50 ppm to zero for a 100,000 gallons/day system.

Capital costs of electrochemical ozone generation systems are about three times lower than similar corona discharge systems, On the other hand, the drawback to electrochemical generation is in higher energy requirements: lSkWh/lb versus 10kWh/lb for a system using less than 10 lb/day of ozone. Energy needs of larger corona discharge systems decrease even further, thereby making electrochemical methods attractive for small-scale uses. The incentives to attempt scale-up lie in the potential of the technology to have reduced capital costs, and the higher ozone concentrations achievable with electrochemical generators provide a wider range of applications for these systems.

Reverse Osmosis

Description. Reverse osmosis (RO) is used to concentrate both organic and inorganic compounds that have been dissolved in aqueous solutions. In theory, the process could be used to treat nonaqueous streams, although presenty there are no known applications of this type. RO competes with ion exchange and evaporation for chemical drag-out recovery. Its advantages over the other techniques are in lower operating costs, the ability for continuous operation, and ease of installation.

The process involves passing the feed stream through a semi-permeabl e membrane under pressure of greater magnitude (400-800 psig) than the opposing osmotic pressure (Figure 4-27). It has been found that it may be necessary to pretreat the waste stream for any of several reasons, including: filtering out unsuspended solids and

4-83 Table 4-25 CAPITAL AND OPERATING COSTS FOR CHLORINATION AND OZONATION SYSTEMS

Capital and operating costs for Ruon plant and chlorination/ Capital and operating cost for dechlorination system. Uail plant and ozone system.

JJml mt!k Enzllish dbetric_ w

Wastewater Flow 14.2 rdlmin 5.4 mgd Design Peak Design Average 8.9 ni /min 3.4 mgd 7.1 dlmin 2.7 mgd Current Average 5.8 nilmin 2.2 mgd 5.0 m'lmin 1.9 mgd Ozone Dosage Design Peak 5.6 mgll 5.6 mgll Current 1.5 mgll 1.5 mg/l Chlorine Dosage Current 1.5 mgll 1.5 mgll Sulfur Dioxide Dosage Current 0.53mgll 0.53 mgl Ozone Demand Design Peak 80 gmlmin 250 ItYday Current 7.5 gmlmin 23.8 Iblday Chlorine Demand Current 8.7 gmlmin 28 Iblday

Sulfur Dioxide Demand Current 3.1 gmlmin 9.8 IWday

Ozone Capital Cost Plant($6,768,000) . $953,0OOh! lmin $2,510,000lmgd Ozone Process($450,000) $63,40O/ni lmin $167,0001mgd ClS9 Capital Cost Plant($5.069.000) $5709000h! lmin$1.490.000/mgd c!sq Process($230~000~ $25,8006 lmin $68,00O/mgd Ozone Operating Cost Plant($470,000) 18 cents/m3 68 centdl000 gal 02 1000 gal 000 gal 1000 gal

Subtota!($l4,57O/yr) 2.10 centdl000 gal CI,SO, Operating Cost Plant($380,000) 47 cents/l 000 gal CI,SO, Process Chemicaf ($3,69O/yr) '46 cents/1000 gal Maintenance($SOO/yr) :06centsll 000 gal Manpower($3,125/yr) 39 centdl000 gal

Subtota1($7,315/yr) .24 cents" 91 cents/l000 gal

* Cost of generation equipment = $250,000, contact basin = $100,000 and building = $100,000 ' Cost 01 chlorinationldechlorination equipment = $15,000, contact basin = $65,000, chemical storage = $30,000, building = $120,000. Electrical efficiency with proposed changes is 25 Whlgm. Price of electricity is 5.5 cents/kWh. Manpower cost is at a rate of $25,000 per year. Price of chlorine 49 centdkg (22 cents/lb.) and sulfur dioxide 89 centdkg (41 centdlb.)

Source: Ref. 24, p. 13

4-84 Table 4-26

COST ESTIMATE FOR REMOVAL OF PHENOL BY OZONATION

(1986$)*

Basis: 800,000 gallday 8 0.38 ppm phenol Estimated Capital Investment: $530,000

Annual Cost per Annual Cost Variable Costs Quantity Unit Quantity ($lyr)

Operating Labor (incl . supervision and overhead) 3,000 hr $18.00/hr $ 54,000 Electricity 1.42~10~kWh $ O.O6/kWh 85,200 Maintenance 8 5% of Investment 26,500 TOTAL VARIABLE COSTS $165,700

Fixed Costs

Capital Recovery (10 yrs 8 10%) 106,000 Taxes and Insurance (2% of investment) 10,600 116,600 TOTAL FIXED COSTS ------TOTAL ANNUAL COSTS $282,000 Unit Cost, /lo00 gal 1.00 Unit Cost, /lb phenol removed $ 3.30

Source: Ref. 2, p. 790 * SAIC estimates

The stream characteristics and ozone requirements we have assumed are: stream flow: 800,000 gallday influent phenol concentration: 0.38 ppm effluent phenol concentration: 0.012 ppm ozone dosage: 20-40 ppm ozone generator output: 190 lb 03/day

4-85 E ru L

W" 1- v)m 1 LN >.W WY- CZW CZ -0 W .r .. Y-a, *r v -L Q3 EO *r v, v,

4-86 film formers in order to assure that all solids remain soluble during concentration, to optimize pH, or to remove oxidizing materials. In addition, chlorination or UV treatment may be used to destroy living organisms, if present in the waste solution.

For a number of years, poor membrane durability held back the use of RO for wastewater purification and reuse. The cellul ose acetate and polyamide membranes once exclusively available were not suited for the high acidity sometimes encountered in metal finishing wastewater. However , the polyether/ amide membrane, which has been commercially available since 1977, is durable over a broad pH range (1-12) and may enhance the use of RO in industry.

Table 4-27 lists successful operations of the technology for the treatment of rinse water streams.

Energy and Cost. The only form of energy needed for the process is electricity. Currently RO systmes require lkWh/100 gallons of product waste and the fraction Of operating costs attributable to energy is 6%.

In general , water recycling systems provide economic benefits through reductions in a number of factors, including the cost for plating chemicals and water, the volume of sol id waste intended for disposal , the water and sewer use fees, and the volume of wastewater which would ordinarily need end-of-pipe treatment. Of these benefits, the value of the reclaimed chemicals is the highest figure contributing to the payback in an RO system. Table 4-28, assembled by Center Corp. and EPA, lists a breakdown of the annual costs and savings (1981 dollars) accrued at an actual bright nickel plating line. At drag-out rates greater than one gallon per hour of plating solution, the payback on the system is 2.4 years. In addition, there are legislative incentives to recycle which include the exclusion of regulation on waste streams of less than 10,000 gallons per day sent to POTWs for all materials other than cadmium, lead, and cyanide.

In conclusion, the value of the drag-out must be significant to provide a large enough return on the investment to make it economically feasible.

Sol idifi cation/Stabil ization

-Description. The term solidification refers to a process in which wastes are treated chemically such that they may be contained within a matrix. The advantages and disadvantages of stabilization methods are outlined in Table 4-29, along with other techniques used for remedial action at waste sites. A 1982 survey conducted

4-87 Table 4-27 APPLICATIONS OF COMMERCIALLY AVAILABLE MEMBRANE MATERIALS

Plating Bzh Membrane Type- Operating Experiance Chemical Confiouratlon Aoolication Omration Criteria and Recommendations Bright nickel Cellulose acetatel Closed-toop drag-out chemical recovery and purified rinse water recycle. Membrane life was a minimum of 18 months. Although spiral wound feed water pretreatment consisting of pre-filtrationwith diatomaceous regularly back-flushed, there is a gradual fouling earth precoat filter andlor micron cartridge filters. Conductivity, flow rates, of membrane. Experienced corrosion inside carbon pressure are monitored; pH (5-6) cot adjusted prior to feed. Surface evapora- steel shell of pressure vessel. Should be stainless tion make-up with demineralized water. Plant start-up November, 1977. steel, plastic, or fiberglass.

Watts nickel Cellulose acetatel Closed-loop drag-out chemical recovery and purified rinse water recycle, No sign of membrane fouling 50 far. Normal operating soiral wound feed water pretreatment consistingof pre-filtration with 10-15 pm cartridge time is 15-24 hru'day. Cumulative operating time filters, pH adjustment to 4.0; conductivity, flow rates, pressure are moni- since start-up is 736 hours. Replace prefilters every tored, water to replace surface evaporation losses is supplied by separate 3-4 days. No problem of algae growth in rinse tanks. RO unit. Plant start-up September. 1979.

Acid copper Polyamidel Open-loop purificationof rinse water overflow from several combined rinses Experiencingapproximately 12-18 months membrane hollow fiber and recycle of rinse water to plating operation. concentrate is further treated life. Using citrus acid buffered ammonium hydroxide for metal precipitationwith lime. Pretreatment of feed consisting of pre-filtra- to wash each stage once a week, further back flush- tion with 10 pn cartidge filter followed by sand filter and 5 pm filter. pH of feed ing is done on each module every month. Average adjusted to 3.0-3.5 flow rate, conductivity and pressure are monitored. operating time is about 13 hourdday. Maximum temperature is 95a"F. n Acid zinc Polyamidel Same as above acid copper except pretreatmentincludes pH adjustment to Average operating time about 22 hrdday. i 6.0 and addition of Bactericide. Plant start-up approximately 1976. co hollow fiber co Copper cyanide Polyamidel Closed-loop drat-out chemical recovery and purified rinse water recycle. feed Approximate membrane life Is 5-1/2 years. No back- hollow fiber water pretreatment consistingof filtration with 10 pm bag-type filter plus 1.2 flushing done at all. Replaces prefilters once per pn 8 0.45 pn cartridge filters in series, no pH adjustment required (pH = 10.0- week on the average. Average operation 8 hru'day. 10.5). surface evaporation make-upwith DI water. Plant start-up approximate- 5 daydweek. ly November. 1974.

Bright nickel Polyamidel Closed -loop drag-out chemical recovery and purfied rinse water recycle. pre- Membrane life approximately 5 years. No backflusing hollow fiber treatment is the Same as copper cyanide unit above, IW pH adjustment (@I = done. Replaces prefilters omper week. Average 7.0), surface evaporation make-upwith DI water. Plant start-up March, 1975. operation 8 hrdday. 5 daydweek.

Acid copper Polyamidel Open-loop purificationof mixed rinse water overflow and recycle of purified Operation 11 hrlday maximum, bacteria and algae hollow fiber rinse water to plating operation. reject containing mixed metal salts is further growth is a problem. Cleaning with formaldehyde is concentrated in solar evaporation ponds. Pretreatment of feed water wnsist- done daily to prevent fouling with bacteria or algae. ing of filtration with diatomaceous earth filter followed by 5 pm and 0.5 pm cart- Hypochlorite solution used every 2-3 months to ridge filters, ultraviolet sterilization and chemical pretreatment limits algae, pH control further algae growth. adjustment prior to RO to 4.5-5.0. Flow rate, conductivity, pressure are monitored. Surface evaporation make-up is demineralized city water. Approximate start-up 1976.

Mixed waste Cellulose acetatel Purification of mixed wastewater effluent from primary treatment system and Membrane life approximately 3 years. Normal opera- heavy metals spiral-wou nd recycle of rinse water to plating operation. Refject is further concentrated in tion 16 hrdday. 5 dayslweek. operation by one engi- (Cu. Cr. etc.) sotar evaporation ponds. Preatment of feed water consistingof filtration in neer per shift plus one laborer, no major problems. gravity filters, vacuum DE filters and 5 pn cartridge filter. pH adjustment to 5-6 prior to RO feed. Designed for zero discharge to sewer. Plant start-up approximately March, 1977.

Source : Ref. 25, p. 22 Table 4-28

ECONOMICS OF REVERSE OSMOSIS SYSTEM FOR NICKEL SALT RECOVERY (1981$) (Operating 4000 Hours per Year)

Iiislnllcd Cost, 550 - Ft ’ Unit

I qtiipmcnt:

I IKIsystem inciudirig 2!, ~ I I 111 tilier. piiiiip $ I !>.000 lis5 IO iiieriibrme units ? Activated mrbon liller $ 2.000 .‘I ~~Jxl~iarif?s,piping nitsc i3 R 2.000 Subtotd $ 19,000 histallation, labor and material $ 2.500 Tot4 instdled cost $2 1.500

Annual operating cost ($/yr.): 1. Labor and maintenance at $1 0.OOhr $ 1.600 2 General plant overhead $ 920

Raw matcrials: 1. Module replacement. 2-yr life $ 1.750 (1 0 x $350/module) x 0.5 yr 2. Resin for carbon filter 3. Prefilter element (25-t)m) s 2% 4. El~ratycosts ($0.45/kWh) $ 1.080

Total operating cost $ 6.533

Annual fixed costs ($/yr):

1. Depreciation. 10% of investment $ 2.150 2. Taxes and insurance, 2% of investment $ 430

TOW fixed costs $ 2.580

Total cost of operation $ 9.1 13

Annual savings (Wyr):

Plating chemicals: 1. 4 lblhr nickel-salt at $1 Ab $16,000 2. 1.5 oz/hr brightener at $0.1 O/oz $ coo Water and sewer charges:

1. Saving 270 galhr @ $O.EO/t 000 gd. $864

Total gross annual savings $17,464

Net savings = annual savings - (operating co>t + fixed cost) Wyr. $ 8.351 $ 6,743 Net savings after taxes. 45% tax rate, 8351x 0.55 t 21 50’ (Yyr)

Average ROI = [net savings after taxesfiotal installed investment $ 31.4 x 100 (%)I

Cash flow from investment = net savings aher taxes i depreciation ($/yr)

Payback period = total installed investmenVwsh flow (yr)

10% investment tax credit = $2150 (or 0.10 x 21.500)

Source: Ref. 25, p. 27

4-89 Table 4-29

ADVANTAGES AND DISADVANTAGES OF CONTROL TECHNOLOGIES

Type Advantages Disadvantages Waste control technologies: Excavation and removal followed by a) Good for containerized or bulk disposal a) High initial costs treatment or disposal b) Potential higher risk during cleanup c) Relocation of risk unless waste is treated d) Not cost effective for low-level hazardous waste or uncontainerized buried waste in large area Excavation with onsite treatment a) Expose waste to complete treatment a) High initial cost option b) No offsite exposure b) Difficult to assure monitoring effectiveness c) Some risk of exposure d) Not cost effective for large amount of low-hazard waste Neutralizationlstabilization a) Useful in areas where waste can be a) Limited application excavated prior to mixing b) Requires long-term land use b) Low risk of exposure if injection regulations method is used c) Eventual offsite migration if reaction is incomplete Biodegradation Low costs Difficult to maintain optimum conditions to keep reaction going Solution mining Useful in homogeneous uncontainerized Can result in uncontrolled release solvent-soluble, buried solid hazardous waste Envlronmental pathway (vector) control: Isolation, containment, and Useful for large volumes of mixed a) Effectiveness depends on physical encapsulation hazardous and domestic waste, and conditions at site low-hazard waste b) Long-term OBM needed Ground water diversion and recovery Useful if soils are permeable or if there a) Requires wastewater treatment option are high or perched water tables b) Process is slow c) OBM monitoring d) Not effective for insoluble or contain erized material Surface water diversion a) Easy to implement Can create flooding offsite b) No transport of waste offsite Ground and surface water treatment a) Can be used onsite or offsite a) May generate hazardous sludges, spent carbon b) Long-term monitoring Gas collection or venting Low costs a) Site safetv and fire hazards d, Offsite ai; pollution c) Long-term monitoring and OBM

--I_ Source: Ref. 18, p. 210

4-90 by the Hazardous Control Research Institute found that solidification and other contaminant treatment processes made up about 16% of the total remedial methods used to control hazardous material s at uncontrolled sites. Tab1 e 4-30 1 ists a breakdown of unit processes and the usage frequency of each.

The following solidification/stabilization methods are described briefly in this section: cement sol idification , si1icate-based processes , sorbent materials , thermoplastic techniques, surface encapsulation, organic polymer processes, and vitrification.

Cement-based solidification involves mixing the wastes slurried in water with Portland cement, resulting in a monolithic, solid or crumbly material. The process is used mainly as a setting agent in other solidification techniques because it cannot by itself contain the hazardous constituents to the extent necessary.

Si1 icate-based processes involve the addition to wastes of such si 1 icate material as fly ash or blast furnace slag together with cement or other hardening agents. There are a variety of propri'etary mixtures available and extensive research has been carried out to discover others. Silicates have been used to stabilize many hazardous materials including solvents, metals, and oils, although applications must be determined on a site-specific basis.

The addition of sorbents to wastes removes free liquid and improves waste handling. Both natural sorbents (e.g., kiln dust, fly ash, bentonite) and synthetic sorbents identified by various tradenames (e.g., Hazorb, Locksorb) are effective in stabilizing wastes. However, secondary containment is generally required to prevent leaching of toxic constituents.

Thermoplastic sol idification involves drying , heating , and then sealing the wastes in a plastic matrix. Costs are high; however, the technique has a comparatively much lower rate of leaching than the others. Bitumen is the most commonly used binder, though paraffin and polyethylene are also available. However, though the method is suitable for heavy metals and electroplating wastes, it is inappropriate for a number of others.

4-91 Table 4-30

TYPES OF REMEDIAL ACTION EMPLOYED AT A SAMPLE OF UNCONTROLLED SITES

--~ -- A Number of Pe rcen t Remedial Action Sitesa Total

- - -I--

Waste Actions:--- Drum and contaminant removal ..... 126 41% Contaminant treatment ...... 48 16 Incineration ...... 3 1 Dredging ...... 5 2 Action on Route of Release-- I_ Cappinglgrading ...... 59 19 Ground water pumping ...... 22 7 Ground water containment ...... 23 8 Encaps ul a tion ...... 8 3 Gas control ...... 3 1 Lining ...... - 7 -2 304 100%

a As many as 25 spill sites may be included.

Source: Ref. 18, p. 211

4-92 Surface microencapsulation involves the sealing of wastes in a shield-like cover formed from an organic binder or resin, thus preventing the hazardous constituents from leaching into the environment. Other advantages include the elimination of the danger of transport spills, and the ability of the encapsulated wastes to withstand chemical and mechanical stresses encountered after landfill ing.

Vitrification involves mixing wastes with molten glass. As the wastes come into contact with the glass, they pyrolize and crystallize into a solid material of very low solubility. The technology is currently being studied for the treatment of transuranic contaminated waste and has the potential to treat other hazardous wastes.

In-si tu treatment processes include radio frequency heating and ground freezing (E). Field tests have been conducted on radio frequency heating for landfills contaminated with organics. In this method a number of horizontal conductors are laid over the landfill in a row and excited with an RF generator. The landfill is then heated with the assistance of steam to 300-400°F. The system involves no excavation and requires a residence time of about two weeks.

Artificial ground freezing involves the installation of freezing loops inserted into holes drilled into the ground. A self-contained refrigeration system pumps coolant around the loop, freezing the soil surrounding the hazardous waste. Figure 4-28 illustrates the two types of systems used in artifical freezing projects: low- temperature ethylene glycol brine, and liquid nitrogen.

The method has not been commercialized, and has never been used in an actual waste containment operation.

Applications. The effectiveness of stabil ization/sol idifaction methods must be validated by testing each mixture of wastes to be contained. Furthermore, secondary treatment is likely to be needed for all techniques except microencapsulation and vitrification. The process requires knowledge and procedures beyond the scope of many potential users; however, there are many companies who can offer the required services and consul tation.

4-93 EXPAnSIOn VALVE

Figure 4-28. Artificial Ground Freezing by Brine (a) and Liquid Nitrogen (b)

Source: Ref. 26, p. 130

4-94 Substances are avail ab1 e in emergency situations requiring the recl amantion and confinement of wastes that have leaked or spilled. O.H. Materials Co., for instance, has developed such a material which they have trademarked ENSOL. It is an anionic polymer and a powerful chelator , reacting instantaneously with heavy metals and showing no degradation after five years.

The product was orginally made to treat concentrated electroplating wastes and now has found uses in preventing the spread of heavy metals and the treatment of such non-emergency situations as acid pits , ponds , and 1 agoons. Costs are $10/gal Ion , with one gallon treating about ten cubic feet of soil containing total heavy metals loadings of up to 3000-mglkg.

The National Materials Advisory Board recommends that continued research on improving solidification techniques and reducing the costs should be carried out. They are hopeful that new developments will lead to long-term economics which are favorable for the burial of solidified wastes in subsurface soils (27).

Energy and Cost. Estimated costs for silicate cement solidification are provided in Table 4-31. It was assumed that 30% Portland cement and 2% sodium silicate were used to solidify 2,850 tons of water for the three types of mixing methods analyzed: in-drum mixing, in-situ mixing, and a mobile cement mixing system. The cost of in-drum mixing is the highest due to high production and labor time, and effectively 1 imits it to highly toxic waste in drums. Costs for thermoplastic solidification of non-radioactive materials are estimated at $20-70 per ton for an asphalt binder-based process. Equipment and energy costs contribute to the high cost of the technique, and special containers must be provided for transportation and disposal of the materials as well.

Encapsulation is relatively costly and energy intensive. For example, the cost is about $50-70 per 80-gallon drum load for the seamless HDPE overpack process, and $90/ton for the polybutadene/HYPE microencapsulation method.

Vitrification has the highest needs for energy and specialized equipment of all the methods available. It also offers the best containment. Table 4-32 shows cost data for five in-site vitrification sites based on glassifying soils to a depth of 15 feet. It can be seen that power requirements make up 35 to 46% of the costs.

The results of a cost analysis of a hypothetical one acre landfill area decon- taminated by radio frequency heating are as fol 1 ows:

4-95 Table 4-31

SUMMARY COMPARISON OF RELATIVE 1985 COST OF STAB IL I Z AT ION/SOL ID IFI CAT ION ALTER NATI VES

Plant Mixing4 Param et e r In- drum In-situ Pumpable Unpumpable

Metering and mixing efficiency Good Fair Excel lent Excellent Processing days required 374 4 10 14 Cost/ ton Re agent $ 24.46 $21.27 521.27 $21.27 (9%)* (63%) (53%) (42%) Labor and per diem 61.09 1.41 3.97 7.19 (23%) (4%) (10%) (14%) Equipment rental 44.43 1.43 4.07 7.02 (17%) (4%) (10%) (16%) Used drums @ $ll/drum 57.69 - (21%) Mobilization- 18.76 I. 64 1.48 2.34 demob i 1i zat ion (7%) (5%) (4%) (5%) _-____

Cost of treatment $206.38 $25.75 $30.79 $38.62 process Profit and 61.91 6.73 9.29 11.59 overhead (30%) ( 23%) (23%) (23%) (23%)

TOTAL COST/TON $248.29 $33.48 $40.03 $50.21

*%of total cost/ton for that alternative. 'Costs updated from 1983 costs using 1985 ENR Index. 2 Assumed 49 gallons of untreated waste per drum and an average process ng rate of 4.5 drums per hour.

3Assumed wastes would be mixed by backhoe with a lagoon and left there Remedial Action is located 200 miles from its nearest equipment. 4Assumed pumpable sludge had a daily throughput of 250 yd3 and the unpumpable 3 sludge a throughput of 180 yd ]day. Remedial Action is assumed to be located 200 miles from the nearest equipment.

Source: Ref. 26 pp. 10-112

4-96 Table 4-32

1982 COST ESTIMATES FOR FIVE IN-SITU VITRIFICATION LARGE-SCALE CONFIGURATIONS

Total Cost Total Cost Manpower of Soil of Soil Number Site Power Heat Loss Level Vitrified Vitrified

3 2 1 Hanf ord Local High Average $187/m $5.30/f t

2 Hanf ord Local Average Average $161/m3 $4.60/f t 3 3 Hanford Local Average Above $183/m $5.20/f t Average

4 Generic Local Average Average $180/m3 $5.10/f t2

5 Generic Portable Average Average $224/m3 $6.30/f t

Source: Ref. 26, p. 9-63

4-97 Capital cost (purchased power) $17 million Capital cost (power generated on-si te) $27.5 million Operating cost $ 4.6-5.7 million

The study found the method to be two to four times less expensive than excavation with incineration.

Cost of artificial ground freezing is shown graphically in Figure 4-29 as a function of freezing rod spacing. The hypothetical site requires a 3-fOOt thick wall which is 1,000 feet long and is sunk to a depth of 40 feet. The overall cost for a frozen wall with a drill spacing of 4-6 feet is about $150,000. Electrical power needs account for 15-20% of this cost.

Suoercri tical Fluid Oxidation

Description. It has recently been discovered that it is possible to break down organic wastes under conditions where water is supercritical (i.e.¶ above 218 atm and 374°C). The process is the basis of a U.S. patent exclusively licensed to Modar, Inc. of Natick, Massachusetts (29).-

The wastes treated may be in the form of liquids, solids, or sludges, although the process is particularly appropriate for aqueous streams containing moderate levels of both organic and inorganic materials. Organic components are converted to water and carbon dioxide, while inorganic compounds are practically insoluble and are thus easily separated out as salts for reuse or disposal (30). In addition, the heating value of the high-temperature, high-pressure waste gases can potentially be recovered for process heat or for the generation of power.

Applications. The development of supercritical water began in 1980. Modar is presently demonstrating the process with a unit having a capacity of 400- to 8000- liters per day, and expects to approach commercialization by late 1986 (2).

Company-sponsored bench-scal e tests found destruction and removal efficiencies to be greater than the 99.99% requirement for DDT, PCBs , and hexachlorobenzene. Uses include regenerating carbon for pesticide adsorption, extracting PCBs from oil, and detoxifying dioxine fluid. A number of potential problems specifically in the areas Of solubility, thermodynamic properties, diffusivities of substances in supercritical fluids, and construction materials under conditions of high temperature and pressure sti11 requi re significant research and devel opment efforts.

4- 98 Frozen Wall 100 x 3 x 40 ft.

500 50 -Overallcost

I I I I I I I I I I I Fuelcosts

THIIIA Equipment Rental 400 40 Days

300 30

200 20

100 10

0 0

2 4 6 8 10

Drill Spacing (ft.)

Figure 4-29. Cost of Artificial Ground Freezing Source: Ref. 28, p. 17

4-99 Energy and Cost. Pumps and compressors make up the majority of the electrical power needs. Modar provided an exemplary power figure of 0.15 kWh/gallon for the treatment of waste streams having a 10% organic matter content. Primary heat for the process is provided by the chemical reactions themselves. Modar claims that costs are competitive with other treatment technologies; however, specific cost data was not available.

Ultrafiltration and Microfiltration

Description. Ultrafiltration (UF) is a separation technology which isolates high- molecular weight solutes from both colloidal and homogeneous solutions. The basic process involves a hydrostatic pressure being applied to the contaminated feed liquid flowing over a porous membrane (Figure 4-30). The membrane retards particles larger then its pore size, typically between 0.001 and 0.1 micron (500-250,000 mol wt) for UF and greater than 0.1 micron for microfiltration. Water and low- molecular-weight solutes (i.e., salts and some surfactants) pass through the membrane pores and are removed as permeate. Emulsified oil and suspended solids that cannot pass through the pores are removed as concentrate.

Membranes have been made from various polymeric materials such as cellulose and fluorinated polymers, typically formed by layers less than a micron thick which are supported on a thicker spongy substructure. They are available in a broad range of molecular weight cutoffs and are made into several forms , including the spiral -wound and hollow-fiber modules shown in Figure 4-31. MF systems range in capacity from 10 to 200 gallons per minute, and the process has proven results of arsenic removal to 0.05mg/lb and heavy metal reduction to less than 0.1 mg/lb.

Applications. U1 trafi1 tration is currently used commercially for wastewater treatment by many industries, including those which produce large amounts of hazardous waste (e.g., chemical , primary metals, and plating). The types of waste produced by industry type and the general benefits of ultrafiltration are presented in Table 4-33.

UF has also been used to treat ink and starch wastewater in the corrugated container industry. These wastes have become a concern since the passing of RCRA due to the restrictions put on landfilling with wastes containing heavy metals. The UF system installed by Koch Membrane Systems, Inc. at a corrugated container manufacturing plant in Auburn, Maine enables the corrugating industry's compliance with the new 1 egi slation by imp1 ement ing a recycl ab1 e , closed-1 oop process (Figure 4-32) .

4-100 Fiberglass-reinforced Epoxy Support Tube

Concentrate

Figure 4-30. Tubu ar Ultrafiltration Membrane

Source Ref. 32, p. 3

4-101 Feed ChanGel Spacer

(Spiral -Wound Module )

Source: Koch Membrane, Inc. , Wilmington, MA

mxv

CONCENTRATE SNAP RING OUTLET

EN0 PLATE FIBER stmi POR END PUTE DISTRIBUTOR TUBZ

(Hollow-Fi ber Module, DuPont Parmasep)

Source: Ref. 2, p. 837

Figure 4-31. Ultrafiltration Membranes

4-102 Table 4-33

MAJOR INDUSTRIES USING KOCH ULTRAFILTRATION TO CLEAN UP WASTEWRTER

INDUSTRY WASTICS IWNEFITS OF KOCH UII~KAI~I1~'I'KA'~'ION

Water ~olublcax)Iants, cutting and 0 c\lta costs and increases efliciency in Femoval of oils, Finding oils, and lubricants uRed in metals, hazardous wantea, pollutants, and solids from rnacliuung opcrntions. water. I)iscliarges from parts washer tanks. rinsewaters, and floor washings. 0 Slashes hauling and disposal oosts. 1L)lling and drawing oils used as Lowere operating and energy coata. lubricants and coolnnts in ferrous and non-ferrous operations. 0 Breaks oil/watm emulsions. Ihulsified and water soluble oily wastes collected by waste haulers from 0 Permeate for discharge to sewer. other industries. Natural fats and oils from animal and 0 Reduces BOD and COD for water treatment. plant processing, particularly vegetable 0 Fkovers valuable products from edible oil manu- oil wastcs. facturing proceas. Latex, emulsions, chemicals and oily 0 Eliminates messy, expensive treatment chemicals. discharges from tank car ckaning 0 Cuts operating costs. 0 Lowers labor costa. operations. 0 Simplifies treatment. 0 Consistent quality of discharge.

Dyes. adhesives. emulsified oils. and 0 Recovers synthetic sizing agents such as polyvinyl sizing clicniicals. alcohol and carboxymethyl cellulose. 0 Saves chemicals by recovery and recycling Indigo dye from wastewater. 0 Lowers waste treatment costs through production of clean water for recycling or discharge. 0 Lowers energy and capital costs for large trcntment capabilities. Plating 1rtdustr.y Metal hvdroxides 0 Eliminates many expensive treatment chemicals. 0 Lowers costs. Vibrating finishing Colloidal nictals. particles labor 0 Simplifies treatment. 0 Consistent quality of permeate. Industrial Laundries Oils, grease and other contaminants 0 Cuts oil, grease, and suspended solids levels in washwater. 0 Eliminates need for treatment chemicals. 0 Reduces BOD and COD in washwater. Printing Flexographic ink and starch 0 Reduces ink solids and starch in waste streams. washwater. 0 Permits reuse of wastearater for rinsing or starch adhesive makeup, or to dilute ink formulations. 0 Reduces total wastewater volume by 96% or more. 0 Concentrates ink up to 25% total solids for ha*. Wood Preservative Oil. grease, penta chlorophenol used to 0 Permits maximum fleniity in choice of wood- treat wood. treatment chemicals since idouscontaminants are removed from wastewater. 0 Reduces cost by recycling of wood-treatment chemicals back into wood-treatment process. 0 Minimizes energy use and operator attention required. 0 Simplifies process to one step requiring no chemicals. 0 Permeate for reuse or discharge.

filp and Pqwr White water, color removal, and other 0 Saves money through generation of dean reusable effluent streams. water. 0 Fkavere valuable chemicals such as hposulfonate and vanillin. ChemicaIs Emulsions, Latex. pigments, paints, 0 Eliminates expensive treatment chemicals. chemicals and unwanted byproduds 0 Consistent highquality discharge 0 Low labor costa. from chemical processing operations. 0 Replaces diatomaceous earth fitera and fiter media to mve capital, operating, and fdter media diadcosts. 0 Reduces labor needed with conventional diatomaceous earth fdtration by at least 80 percent 0 Cleans up wastewater economicallv to mater than 99%purity.

-- Source: Koch Membrane Systems, Wilmington, MA

4-103 *

I I J

n N Cr)

rc W & .. W u L =I 0 v)

(u _-- L =I 01 *I- LL

4- 104 New legis1ation has a1 so prompted UF applications in wastewater streams con taining emulsified oil from waste cutting and grinding operations, alkaline degreasing baths, and waste-roll ing oil solutions. A generalized flow schematic is illustrated in Figure 4-33, and the operating characteristics based on an analysis of operating results from commercial instal 1 ations are presented in Tab1 e 4-34.

Koch has found a similar niche for UF in the wood preservative industry. In this case UF separates the oil, grease, and pentachlor-phenol (PCP) from steam condensate generated in the pressure-treatment of wood and poles. The resulting water permeate is clean enough to discharge to the sewer, and the PCP can be recycled into the wood treatment process.

Commercial UF systems are also used to treat wastewaters contaminated with heavy metals and chemicals produced by the printed circuit, semiconductor, and electroplating industries. Permeate concentrations reportedly achieved by a microfiltration system produced by Memtek of Billerica, Massacusetts are entered in Table 4-35 along with the corresponding discharge limits. Memtek also has systems currently operating to purify wastewater contaminated by lead in battery manufacturing facilities, by silver in photographic processing plants, and by arsenic in the electro-optical industry. The process used in these systems first involves the use of pretreatment chemicals to convert contaminants to a filterable size, after which the fluid is sent through tubular membrane microfiltration modules at a fluid pressure of approximately 20 to 40 psi.

Energy and Cost. UF is economically competitive with other treatment technologes (it is generally less costly than chemical treatments systems, for instance) and relatively easy to operate. New advances in membrane technology have contributed to lower these costs even further and have broadened the scope of its usage in indust ry.

A comparative investment analysis done of the UF treatment system at the corrugated container plant is given as an example, and is shown in Tables 4-36 and 4-37. The total yearly operating cost for the UF system was $19,300. When compared to the commonly used management technologies of hauling and evaporation by drum drying, UF paid for itself in less than 1-1/2 years.

4-105 Waste Emulsions Concentrate Recycle

Permeate

Figure 4-33. Modified Feed and Bleed Semi-Continuous Batch Treatment

Source: Ref. 33, p. 3

4-106 Table 4-34

OPERATING CHARACTERISTICS, UF OIL EMULSIONS

Permeate flux 45-90 L/m2h 25-55 GPD Energy needs 10-15 kWh/m3permea te

Cooling water requirements 0

Detergent for 25 gfm3 of permeate; 0.2 membrane cleaning 1b/1000 gal 1 ons of permeate

Manpower 7-10 hfweek

Mem b fane > 12 months rep1 acement

Source: Ref. 33, p. 4

4-107 Table 4-35

MICROFILTKAT ION SYSTEM PERFORMANCE

Memtek system performance Printed circuit board manufacturer*

raw discharge Memtek assay wastewater limit effluent o-xl/l) “/I) “/I)

Cr 20.0 0.5 0.1 cu 27.0 1.o 0.2 Ni 11.0 1.o 0.4

Pb 6.0 0.5 0.07

Electroplating operation*

Ag 100 0.24 0.1 Cd 115 0.26 0.05 CN 75 0.65 0.1 Cr 80 1.71 0.1 cu 600 2.07 0.1 Ni 150 2.38 0.05

Zn 50 1.48 0.1

Source: Memtek Corporation, Billerica, MA

4-108 Table 4-36

OPERATING COST ANALYSIS FOR THE PROCESSING OF FLEXOGRAPHIC INK/STARCH ADHESIVE WASHWATEK

BAS IS: 5,000 Ga 1/Day UF-158 to concentrate solids from 1% to 25% TS 98% volume reduction 250 days/year of operation

CAPITAL COST

UF-158 System $58,000.00 Installation $ 5,000.00 Total $63,000.00

OPERATING COST

Power $ 2,900.00 (O.OS/absorbed kw-hr) La bo r $ 7,500.00 (2 hourslday (3 $15/hr) Membrane Replacement $ 3,200.00 (2 year life) C1 eaning Chemicals $ 2,700.00 Maintenance $ 500.00 (1% of non-membrane capital ) UF Concentrate Hauling $ 2,500.00 (2% of volume)

Total $19,300.00

UF SAVINGS: 25 X concentration (96% volume reduction)

when compared to l-effect vs. hauling drum dryer evaporation (3 $O.lO/gallon (3 $9/1,000 lbs steam

$125,000 $ 91,900 (energy) $ 2,500 (haulinq concentrate) $ 8,000 [maintenance estimate) Total

Source: REf. 32, p. 11

4-109 Table 4-37

INVESTMENT ANALYSIS FLEXOGRAPHIC INK/STARCH WASTEWATER

UF-158 U1 trafi1 tation System 5,000 gal 1 ons/day 98% volume reduction

Installed UF-158 System Price = $ 63,000 Capital Recovery (5 year straight 1 ine on nonnembrane capital equipment) = 5 10,656/year

Savings :

when UF is compared to when UF is compared to haul ing at fO.lO/gal lon drum dryer evaporation

5 125,000 5 102,300 UF Operating Costs 5 (19,300) 9 (19,300) UF Net Income $ 105,700 5 83,900 Income Less Capital Recovery 5 95,044 $ 72,344 Less 50% Taxes 5 47,522 $ 36,172 Cash Flow (After Tax Income Plus Capital Re covery ) $ 58,178 5 46,828 After Tax ROI 92.3% 74.3% Payback Period 1.08 years 1.35 years

Source: Ref. 32, p. 12

4-110 In general , capital costs vary according to flow rates and type of system used (i.e., single-pass, recirculating, high-flux, etc.) , though typical values range from $35,000 to $65,000. Operating costs are low, on the order of $0.015 per gallon for the ink and starch wastewater decontaminating unit.

Electrical power for pumping is the sole energy cost associated with UF system operation, and this falls in the range of 3.5 to 6.0kWh per 100 gallons of permeate. Energy requirements for Memtek's microfiltration systems, with capacities from 20 to 132gpm, are approximately 1.2 to 2.9kwh/100 gallons of permeate.

U1 t raviol et Rad ia ti on

Description. In order for ultraviolet light to detoxify hazardous wastes the radiation source must be sufficiently energetic to break the appropriate chemical bonds. The waste stream must also be clear enough to allow the radiation to be absorbed by the target species. Table 4-38 lists some hazardous substances which can theoretically be broken down by photolysis, a1 though no commercial application in the treatment of wastes using UV alone has been identified.

Ultraviolet light has found applications in waste treatment where it is used as a catalyst in oxidation reactions. In this application UV increases the oxidation potential of detoxifying reactions in the presence of oxidants such as chlorine, ozone, and hydrogen peroxide. Ozone and hydrogen peroxide work best to detoxify hazardous wastes , with hydrogen peroxide being the more efficient oxidant since it forms two free hydroxyl radicals per molecule whereas ozone forms only one.

-II_Applications. Although no bench-scale or fully operating systems employing treatment by UV 1 ight alone were identified , several UV-catalyzed processes have been devel oped. For example, preliminary experiments reported by IT Corporation of Knoxville, Tennessee have been successful in detoxifying dioxin-contaminated soil. In the tests the soil was sprayed with a 0.5-3% w/w solution of organic surfactants and irradiated with mercury vapor lamps. The process was found to reduce the dioxin concentration in the soil by 98%.

These results at the site in Missouri suggest that detoxification of selected areas is feasible. Future research is still needed to examine the rate of solubilization vs. the rate of photolysis, the effect of surfactant concentration, and the importance of soil mixing (E).

4-111 Table 4-38

CHEMICAL CONTAMINANTS TREATABLE BY UV UESTRUCTION

acetaldehyde glycol 5 acetic acid ha1 oaryl ethers a1 co hol s ha1 ogenated methanes amines hydroqui none a roma t i'cs nitrosamines benzidines nitroaromatics benzoic acid nitrophenol s chel ating compounds organic phosphates c hlor i n a t ed butanes organosul phur compounds chlorinated ethanes organo-ti n compounds c hlor ina ted pentanes pesticides c hl o rin ated pol ya romat ics phenol s chlorinated propane phthalate esters chl oroaromatics polyaromat ic s chl orophenol s polychlorinated biphenyls cyanide RD X detergents sodium acetate ethylene dichloride styrene formic acid sugars glycerol s TNT glycine vinyl chloride

Source: Ultrox International, Culver City, CA

4-112 Peroxidation Systems of Tuscon, Arizona, planned to install a UV system for treating contaminated groundwater in Sacramento on Apri 1 1, 1986. Unfortunately, specific information regarding cost and energy requirements, on this and other systems they have installed, is proprietary.

U1 trox International of Culver City, California performs treatability testing and on-site pilot studies, has mobile demonstration units available, and installs UVIozone systems for hazardous waste destruction. They have developed a process to reduce the concentration of chlorinated hydrocarbons in water and wastewater using photo oxidation and the liberation of chloride ions. A turnkey system that carries out this process is commercially available and one unit has been installed for the treatment of contaminated groundwater at a large processing facility. The reactor treats up to 500,000 gallons per day depending on the degree of oxidation required and the nature and concentration of the contaminants. It can be operated with existing equipment for pretreatment or final polishing or as a stand-alone process.

Ultrox have designed a water purification plant to destroy small quantities of both high and low concentrations of refractory and toxic organics in water. The unit can treat 60 to 40,000 gallons a day, and can function in the presence of heavy metals, salts, color, or non-refractory organics. It is designed to be transported to an industrial wastewater treatment site for use on a slipstream of contaminated water. Table 4-39 contains the major operating parameters of the unit.

Radiation Disposal Systems has devel oped a patented UV/ozone treatment process for low-level radioactive waste. Disposal of the substantial amounts of such contaminated wastes as exchange resin, papers, and tissues has been a problem, with refuse piling up from hospitals, power plants, and industry. In this new process the wastes are ground in a water slurry, treated with UV/ozone, concentrated, and then treated further prior to storage or recycling.

Bollyky Associates, Inc. of Norwal k, Connecticut designed a UV/ozone reactor and an ozone and hydrocarbon destruction unit for the treatment of the reaction off-gas. The process has been tested in the laboratory, and pilot plant operations were scheduled for mid-Spring of 1986. Results of these test have not been obtained to date.

Research is needed to improve the efficiency of UV lamps, to decrease the operating and capital costs of ozone generation, and to better achieve the interface between ozone, ultraviolet 1 ight, and wastewater.

4-113 Table 4-39

SPECIFICATIONS ON ULTROX PILOT PLANTS

Model # P-75

Dimensions (W x L x H) 28" x 45" x 45"

Weight (lbs) 900

Tank Capacity (ga ) 75

Continuous fl ow capacity (gpm) 0.5-5.0

Ozone Air (lb/day) 0.5-50.0

# of UV lamps 30 (max)

Input voltage* 115

Circuit breaker rating (amps)* 22 0

* Does not include ozone generation power

Source: Ultrox International, Culver City, CA

4-114 Energy and Cost. The UV/ozone systems designed by Ultrox require 0.2 to 1.4kWh/100 gallons of wastewater treated. Costs range from $0.05-0.50 per gallon, although these esti mates may inc rease wi t h hig her contami n an t concen t rat ions .

Wet Air Oxidation

Description. Wet air oxidation (WAO) at elevated temperatures (170°C to 350°C) and pressure oxidizes organics in water. The pressure and heat cause the molecular structure of aqueous wastes containing cyanide, sulfides, phenolics, pesticides, and other organic contaminants to break down into such simple, biodegradable substances as water and acetic acid (35).- The process has shown the ability to treat most of the compounds on the EPA priority pollutant list with a destruction efficiency of over 95%.

During the WAO process (Figure 4-34), the waste stream is pumped into the reactor at a high pressure, with systems designed to run at pressures of up to 1250- to 2000- psig. Prior to entering the reactor, the feed stream is preheated with the treated mixture, and in some cases is also preheated with hot oil from an electrically- heated oil heater. Oxygen is mixed with the preheated feed from an air compressor, and the mixture is further heated as it enters the reactor and encounters exothermic reactions. After the contaminants are oxidized in the reactor the liquid passes through the hot, cool-down side of the heat exchanger and goes to the separator where the non-condensible gases are separated from the liquid phase.

The process is most useful for aqueous streams with less than 5% organics. At higher concentrations incineration becomes more economical, and at very low concentrations biological techniques are more efficient.

Applications. Several kinds of wastes have been treated with wet air oxidation in the past few decades, but with the recent focus on the treatment of hazardous wastes several companies have been performing bench-scale and pilot plant research on various hazardous organic wastes. The process is now available on a commercial scale from several sources. Casmalia Resources, a Class I landfill facility in Santa Barbara County, California, has a Zimpro wet air oxidation unit which was granted an operating permit by EPA in October, 1982. The unit is designed to process liquid wastes at a flow rate of 2.3m3/hr, a temperature of 280°C, and a pressure of 136atm.

4-115 Reactor

Air 1

complessor High presswe pump

Separator

Figure 4-34. The Wet Air Oxidation (WAO) Process

Source: Ref. 36, p. 107

4-116 Zimpro has put three other hazardous waste wet air oxidation facilities into operation. One system is part of a program that is testing six detoxification technologies to clean up contaminated soil and groundwater and chemical wastes at a site near Muskegon, Michigan. In general, the WAO unit treats concentrated wastewater streams with organic components of 600 to 1,200ppm and total oxygen demands of over 150 g/l. The process produces an effluent which is biodegradeable, has a BOD/COD ratio of about 0.66, and an organic destruction rate of 99.8% (2).

Another Zimpro WAO application treats caustic liquor from ethylene manufacturing. The process oxidizes sulfide and cyanide wastewater, rendering them treatable by an activated sludge unit which follows. COD reductions have been about 60% and residual sul fide concentrations have been bel ow lmg/l (38).

At Dominion Foundaries and Steel Co., recently a steelmaker in Hamilton, Ontario, Canada, a Zimpro WAO unit was installed to treat coke oven gas scrubbing liquor ( ammoni um thiocyanate). P1 ans to crystal 1i ze and recover ammonium sulfate and to recycle sulfuric acid were in progress at the time of installation (2).

Energy and Cost. WAO requires a significant amount of electrical or mechanical energy, with power requirements typically consuming about 42% of the total operating costs when electricity is at $0.03/kWh. Table 4-40 provides a breakdown of capital and operating costs for a typical WAO system. As a side note, though off-gases separated from the oxidized effluent may be expanded in a turbine to generate electrical or mechanical energy to supply the pump and compressor, this type of power recovery is economically efficient only for 1 arge systems. Capital costs range from $1.0 to 4.0 million (Figure 4-35) and operating costs are about $0.02/gal of wastewater treated. Estimates of operating costs according to the flow capacity of a system are plotted in Figure 4-36.

4-117 Table 4-40

COSTS OF A TYPICAL WAO SYSTEM

Instal 1ed Capital Cost, $ millions 1.8 1.2

Operating Cost, $: Fuel...... -- 878,500 Power...... 56,000 9,000 Steam...... -- (544,000) Maintenance...... 45,000 120,000 Labor...... -- -- (same) Add4 tional Treatment Surcharge...... Chemicals......

Total Operating Cost, 8.. $132,ooo $463,500

Source: Ref. 40, p. 52

4-118 5 I I I I I I 5

01 I I I I I I 10 20 30 40 50 60 WAO UNIT CAPACITY, GPM (US.)

ASSUMPTIONS: UNIT DESIGN 536"F, 2000 PSlG 1985 COSTS. 50 g/L COD REDUCTION COSTS DO NOT INCLUDE BUILDING OR FOUNDATIONS

Figure 4-35. High Pressure Wet Air Oxidation Installed Unit Capitol Cost vs. Wet Air Oxidation Unit Capacity

Source: Zimpro Environmental & Energy Systems, Rothschi Id, WI.

4-119 2.0

1.5

10 20 30 40 50 60 70 WAO UNIT CAPACITY, GPM (U.S.)

ASSUMPTIONS: UNIT DESIGN 536"F, 2000 PSIG POWER $O.OYKWH, 50 g/L COD REDUCTION COOLING WATER $0.25/1000 GAL LABOR $18/MAN HOUR MAINTENANCE 2% OF CAPITAL COST

Figure 4-36. High-pressure Wet Air Oxidation Unit Operating Cost vs. Flow Rate

Source: Zimpro

4-120 REFERENCES

1. "Hazwaste Problems Noted." World Wastes, November 1985, p.38.

2. D.J. De Renzo. -Unit Operations for_l_l_l_- Treatment of Hazardous Industrial Wastes. New Jersey: Noyes Data Corporation, 1978.

3. The CBI Indirect Freeze Process. Plainfield, IL: CBI Industries, Inc., August 1984.

4. Edward F. Hradil and George Hradil. "Electrolytic Recovery of Precious and Common Metals." Metal Finishing, November 1984, pp. 85-88.

5. U.S. Environmental Protection Agency. Industri a1 Techno1 ogy Divi si on. Env ironmen tal Reg ul ati ons and Tec hnol ogy , --The Elec t ropl ati ng Industry. Cincinnati, Ohio, September 1985, p. 44

6. North Carol ina DeDartment of Natural Resources and Community Development. Division of Environmental Management. Drag-out Management-- for Electro- plating. p.7

7. U.S. Environmental Protection Agency. Industrial Environmental Research Laboratory. --Control and Treatment Technology for the Metal Finishing Industry. Cincinnati, Ohio, January 1982, p. 33. EPA 625/8-8r008.

a. Andco Environmental Processes, Phone conversation of March 27, 1986.

9. Andco Electrochemical Heavy Metal Removal System for Wastewater Treatment. Andco tnvi ronmental Processes, Inc., 1984.

10. William F. Owen. Energy in Wastewater Treatment. New Jersey: Prentice-Hall , Inc., 1982.

11. Shahryar Sefidpour. State-of-the-Art Survey of Mechanical Dewatering Systems. Los Altos, CA: SAIC, January 23, 1986.

12. Thomas S. Barron. "Use of Freeze Crystal 1 ization Systems for Concentration of Liquid Hazardous Waste." In Proceedings of the Hazardous Materi a1 s Management Conference and Exhibition, April 29 - May 1, 1986, pp. 478-486. 13. Emer in Technologies for the Control of Hazardous Wastes.- Washington D.C.: m<*hmation, MaTTh 1982. PB82-2-3.

14. U.S. Environmental Protection Agency. Municipal Environmental Research

Laboratory. "Treatment of Hazardous Wastes." In I_-Proceedings of the Sixth Annual Research S m osium San Antonio, Texas: Southwest Research Institute, March 1980. -e 15. Advanced Waste Treatment Options, The Huber Advanced Electric Reactor and the Rotary Kiln Incinerator. Borger, Texas: J.M. Huber Corporation, 1985, p. 16.

16. Field Demonstration of the Destruction of Dioxin in Contaminated Soil Using the

J .M. Huber Corporation Advanced t I eftxReactor.r-%%sthester,-PA-I- : Roy Weston, Inc. and Denver, CO: York Research Consultants, February ll, 1985.

17. J.M. Huber PCB Destruction Process Trial Burn Report.- Austin, Texas: Radian Corporation, October 31, 1983.

4-121 18. U.S. Congress. Office of Technology Assessment. Technologies and Management

Str-ies for------I Hazardous Waste--I--- Control. -_ Washington, D.C.: Government Printing aTF ice ,TTT.

19. Irwin Frankel , Neil Sanders, and Greg Vogel. I' Survey of the Incinerator Manufacturing Industry." Chemical Engineering _I--.-Progress, March 1983, pp. 44-55.

20. California Department of Health Services. Toxic Substances Control Division.

-I__~-A1 ternative Technoloxfor Recycl in3 and I-Treatment of Hazardous~ Wastes. Second Biennial Report, July 1984.

21. Marshal 1 Sittig. Incineration of Industrial-- Hazardous Wastes and Sludges. New Jersey: Noyes Data Corporation, 1979.

22. B.L. Hertzler. "Microwave Plasma Destruction of Toxic Wastes." Lockheed Missiles and Space Co., Inc., July 1982.

23. Peter C. Foller and Mark L. Goodwin. "Electrochemical Generation of High-

Concentration Ozone for Waste Treatment ." ----I_.Chemical Engineering Progress-I__ , March 1985, pp.49-51.

24. Proceedings of the Ozone for Water and Wastewater Treatment Program. Newark, 83: Public Service Electric and Gas Company, October mc 25. Peter Crampton. "Reverse Osmosis in the Metal Finishing Industry." Metal ---FinishiN, March 1982, pp. 21-27.

26. U.S. Environmental Protection Agency. Office of Emergency and Remedial

Response. Handbook____ll_l--- of Remedial Action at Waste Disposal Sites. Washington, D.C. : Governmental Printing Office, 1985.

27. National Research Council. National Materials Advisory Board, Commission on Engineering and Technical Systems. Management of Hazardous Industrial Waste: Research and Development- Needs. Washington D.C.: National Academy Press , -rxc--

28. Economics of Ground Freezing for Management of Uncontroll ed Hazardous Waste Sites. Hanover, NH: Thayer School of Engineering , October 1984. (Avail able from NTIS as PB85-121127).

29. U.S. Environmental Protection Agency... Hazardous Waste Engineering Research Laboratory. Incineration and Treatment of Hazardous Waste Proceedings__- of the -lll__ll__l____l____llll___I

1_----__-1_Eighth Annual Research Sympossium. Ohio: Government Printing Office, 1982.

30. U.S. Environmental Protection Agency. HW Engineering Research Laboratory. ----Innovative Processes for HW Treatment and Destruction. Cincinatti , Ohio., August 1985. (Available from NTIS-Pm736032).

31. William Killilera, Ph.D. Natick, MA: Modar Inc. Phone conversation.

32. Ultrafiltration for the Treatement of Ink and Starch Wastewater in the --I------_I_ ____I______lll-l-l-l------Corrup&d Container Industry. Auburn, ME: Richard Parsons Allied Container ErF6ratiGrd- Wilmi ngton, MA: Abcor, Inc.

33. Ultrafiltration-l--l__-----~---II for Dewateringof Waste Emulsified Oils. Wilmington, MA: Abcor, Inc.

34. Jurgen H. Exner. "In-place Detoxication of Dioxin-Contaminated Soil" Hazardous ~--Waste, vol. 1, no. 2, 1984.

4-122 35. James L. McBride. "Wet Air Oxidation Destroys Chemical Wastes at Class I Landfill Site." Chemical Processing, October 1983.

36. A.R. Wilhelmi and R.B. Ely. "A Two-step Process for Toxic Wastewaters." --Chemical Engineering, February 16, 1976, pp. 105-108.

37. L.A. Badonick and A.R. Wilhelmi. "Mu1 ti-Faceted Approach to Successful Hazardous Waste Treatment." Pollution Engineering, April , 1984.

38. "Positive Results with Wet Oxidation." Reactor, no. 49, October, 1982.

39. "Helping Steel Kick the Coke Oven Gas Habit." Reactor, no. 41, February, 1979.

40. A.R. Wilhelmi and P.V. Knopp. "Wet Air Oxidation: An Alternative to Incineration." Chemical Engineering Progress,- August 1979, pp. 46-52.

41. Gessner G. Havley. The Condensed Chemical Dictionary.-- New York: Van Nostrand Reinhold Company, 1981.

42. Carl N. Staszak. Buffalo, N. Y. : CECOS, International , Inc. Phone Conversation.

43. North Atlantic Treaty Organization. Committee on the Challenges of Modern society. Pilot Study on Disposal of Hazardous Wastes: Thermal Treatment. Brussel s, Belgium , March 1981. 44. Beth1 ehem Steel Corporation , Research Department , Techno1 ogy Group , Electric Arc Furnace Dust, Project Number RP-2570-1-2, May 1985. 45. Plasma Processing in the U.S. Chemical,-Industry, Palo Alto, CA: Electric Power Research Institute, November, 1985, EM-4336.

4-123

Section 5

NUCLEAR WASTES

Disposal of nuclear waste continues to be a major source of controversy in the United States. Although the technical community has emphasized that nuclear waste can be safely disposed of in geologic media, strict regulations and institutional factors remain as major obstacles in the way of large-scale demonstration projects in the U.S.

There are five major sources of nuclear waste generation:

0 Commercial fuel cycle

0 Defense-related activities

0 Institutions (hospitals, universities, etc.)

0 Industrial uses of isotopes

0 Mining and milling of uranium ore

There are several classifications of nuclear wastes: high-level wastes (HLW) , transuranic wastes (TRU) , low-1 eve1 wastes (LLW) , and spent fuel .

0 High-level wastes are typically liquids that are produced in reprocessing spent fuel (Figure 5-1) and contain fission products and transuranics; they are therefore sel f-boil ing and intensely radioactive. Even though there is no commercial reprocessing of spent nucl ear fuel s in the U.S., defense-re1 ated nucl ear wastes are reprocessed at DOE sites. HLW are generally solidified and deposited in a deep geologic repository.

0 Transuranic wastes are those materials contaminated with alpha- emitting radionuclides of long life and activity levels of greater than 10 nanocuries/gram. TRU results from fuel processing and plutonium fabrication and requires non-biological shielding and remote hand1 ing.

0 Low-level wastes generally have small amounts of radioactivity in large volumes of material, and are primarily made up of items contaminated by contact with radioactive matter. These wastes are secluded in shallow land burial sites at controlled locations.

0 Spent fuel is made up of intact assemblies of fuel near the end of their useful life in a nuclear reactor. These assemblies contain most of the uranium originally loaded as fresh fuel together with

5-1 Cladding and Hardware

Uranium Reprocessing Spent Fuel

Plutonium

Figure 5-1. Origin of High-Level Waste

Source: Ref. 4

5-2 the fission products and transuranics formed as a result of the reaction of fissionable nuclei (U-235) and neutron capture of fertile nuclei (U-238). If not processed, spent fuel is delivered to geologic disposal as a waste material. Table 5-1 illustrates the current generation rate and accumulation of nuclear wastes.

Table 5-1

SUMMARY OF GENERATION AND INVENTORIES OF NUCLEAR WASTE

---- TY Pe -Generation Rate Accumulation to 1985

Spent fuel 2400 MT of Ur 15,800 MT Transuranic wastes 4400 m3/yr 361 x lo3 m3 HLW Defense N/ A 306 x lo3 m3 33 Commerci a1 N/ A 2.2 x 10 m LLW 200,000 m3 3,432,500 m3

Source: Ref. 2 U.S. Inventory of nuclear waste, DOE

MANAGEMENT OF NUCLEAR WASTES IN THE U.S.

The strategy for management of nuclear waste in the U.S. is geologic isolation of spent fuel, immobilization of high-level wastes, geologic isolation of transuranic wastes, and engineered surface storage or burial of low-level non-TRU wastes. Figure 5-2 represents the management strategy of nuclear waste in the United States.

PROCESSING TECHNOLOGIES

As illustrated by Figure 5-2, there are two areas in the processing of nuclear waste that afford the potential for the application of electrotechnolgies, specifically: volume reduction and sol idification/encapsulation.

5-3 High-Level Low-Level Wastes Transuranics Wastes Spent Fuels U rm All Repoa ng and Rewomssiw Source - L so -1s -Refabic, nPlan*l Plants

Temporary Storage

---, r--- I------___-1 I volume ' I Process ' I Solidifyand I , Encapsulate ! Processing I Reduction ' I AsNeeded I Encapsulate I I I

On-Site Geologic rStorage RepOSitWy

Figure 5-2. Proposed Reference U.S. Nuclear Waste Management System Source: Ref. 4

5 -4 Aqueous Calciner Waste I I b- Heat

Calcine

Glass Formers b Melter 4- Heat

Canister

v cod and Solidify

Figure 5-3. Reference HLW Conversion System

Source: Ref. 4

5-5 High-Level Waste Treatment Vitrification

High-level wastes produced in reprocessing nuclear fuel are in a liquid form and must be solidified for interim storage and long-term disposal; in most processes this takes the form of conversion to a glassy material, or vitrification. The insoluble glass is the first engineered barrier in a geologic disposal scheme composed of waste, engineered barriers, and geologic barriers.

The HLW vitrification systems adopted in the U.S. calcine the aqueous wastes, mix it with glass-forming reagents, and then melt the mixture using heat. The melted mixture then cools to form a hard, glassy product which has good physical stability and low solubility in liquids, such as the ground water that could penetrate its dis posal 1 oca t ion.

The HLW conversion system has three major components: the calciner, the melter, and the waste canister (Figure 5-3).

0 Calciner. The aqueous waste is sprayed into a chamber heated to about 700°C. The condensed droplets of waste are dried and calcined (mainly to oxides) with heat. Off-gases are cleaned of particulates by filters entering the ambient air.

0 Melter. Both batch and continuous melters have been highly developed in the U.S. The in-can (batch) melter (Figure 5-4) consists of a waste canister contained in a 6-zone furnace. Glass- forming frit is fed with the calcined waste into the canister and heated at a temperature of about 1050°C until it is melted. When the canister is filled, the calcined material and frit are diverted to an empty canister. The filled canister is cooled by forced air and then removed from the furnace.

The in-can melter is well developed. It has been demonstrated in systems for labs, pilot-plants, and plants. To date, more than 40 canisters of non-radioactive glass and two of actual radioactive glass have been produced, including those of a large enough diameter (20-24 inch canister) to have a throughput of about 90 kg/hr thereby approaching the requirements for defense waste needs.

In the joule-heated, continuous ceramic melter (Figure 5-5) the calcined waste and frit are fed into a ceramic-lined chamber. The mixture is then melted by an alternating current which passes between electrodes in the melter. The mixture of frit and calcined waste is melted continuously and overflows into a canister or into molds for producing glass shapes.

The joule-heated continuous melters have produced over 17,000 kg of nonradioactive waste for over three years without serious degradation. A large-scale ceramic melter has been operated at glass throughputs of up to 130 kg/hr since 1977. This melter has the ability of accepting liquid waste directly, thereby eliminating the cal ciner.

5 -6 5-7 LLI Q zW Y a 0

U w 5 z a 0 w I- oa 3

5 -8 Low-Level Waste: Volume Reduction Systems I Several waste treatment systems are currently avai 1 ab1 e for deal ing with 1 ow-level nuclear wastes. Generically, they are known as "volume reduction" (VR), and they remove non-radioactive materials--primarily air, water, and combustible organics-- from the low-level nuclear wastes, thus reducing the volume of waste requiring final disposal .

VR equipment and systems, currently sold by nine companies within the U.S., can be divided into four types: incineration, dehydration, compaction and crystall i- zation. Incineration primarily removes combustible organics, but water and air can a1 so be removed concomitantly. Dehydration removes water from wet wastes, leaving a dry residue. Calcination processes are grouped together with dehydration processes, although calcining can remove other volatiles from the wastes along with the water. Compaction reduces the volume of dry active waste (DAW) by baling or compacting the contaminated trash into drums. Water is evaporated from liquid wastes in the crystallization process, the residue consisting of a viscous slurry of solids in a saturated solution.

The dried wastes are typically solidified with cement, bitumen, urea-formaldahyde, vinylesters, polyethelene, epoxy resins, or in organic binders.

0 The Pyro-converter system manufactured by Penberthy uses gas heated to 1260°C to melt crushed, non-radioctive glass and keep it molten by maintaining the temperature through electric heating. Radio- active wastes are fed onto the surface of the molten material, then the glass is solidified in drums for shipping and final disposal.

0 A Blender/Dryer is made by TeledynelReadco. The waste is dried in an evaporator and then fed into a hopper where solidification agents are added and mixed. Afterward, the mixture is ransferred into drums.

0 HPD, Inc. supplies one evaporative crystallizer coupled with an in- drum mixing cement solidification system.

0 Hi 1tman Nuclear and Development Corporation markets a thin-fi lm evaporator that operates as a crystalli zer receiving radwaste from another evaporator. The device is coupled to a high shear mixer where cement is mixed with the waste, after which it is drummed and capped for storage or shipment.

0 The Westinghouse VR and solidification system uses a semicontinuous, vacuum-cooled crystall ization process to concentrate 1 iquid wastes. Waste crystal slurry is solidified with cement and automatically packed in waste disposal containers.

5-9 0 Werner and Pfleiderer Corporation markets a combined evaporator with a solidification system. Waste dried in an extruder evaporator is mixed with heated bitumen which is solidified in a container suitable for disposal, when cooled to room temperature.

0 Associated Technologies, Inc. a1 so manufactures an evaporator- /sol idification system. Wet sol id waste and electrically heated bitumen are concentrated in a thin-film evaporator. In this process the waste/ bitumen mixture is spread as a thin film on the treated interior of the evaporator which removes the water from the mixture. The dry waste and bitumen are then put into a disposal container where the mixture solidifies when cool. This system removes 99% of the free water from solid waste, and can solidify 2/3 pound of dry waste per pound of bitumen,

0 Two other systems available in the U.S., by Aerojet Energy Conversion Company (AECC) and the Newport News Industrial Corporation (NNI), are fluidized-bed dryerlincinerators. The AECC system uses a fluidized bed for the concentration of liquid radwastes and a separate fl uidized-bed incinerator for DAW. The output from this system is about 65 parts dryer product to 3 parts ash from the DAW incinerator, and is put into containers in this ratio and employing cement solidification. The drum loadings for this system are about 400 pounds of dry product per drum.

The NNI system utilizes a single fluidized bed for liquid waste drying, combustible waste incineration and ion exchange, and filter sludge incineration. Only one mode is run at a time, with each mode having a separate feed system.

U1 trafiltration

Large amounts of low-level, aqueous radioactive wastes are produced during the operation of a light water nuclear reactor. These wastes must be reduced in volume to minimize the number of off-site waste shipments. Ultrafiltration (UF) is a pretreatment method for processes such as reverse osmosis or carbon adsorption. Radwaste evaporators can improve their effectiveness by uti1izing UF as pretreatment.

UF is a low-pressure membrane technology, with concentration factors ranging from 400 to 2000. Membrane decontamination factors (defined as the ratio of concentration inlet to outlet for a species) are about lo5 for filterables and between 1 and 20 for nonfilterable species. The electricity usage for a 2 gpm UF system is about 22.2 MWhlyear .

5-10 SUMMARY

The future of nuclear waste handling is still uncertain. No long-term government policy has been established for handling and disposal of spent nuclear fuels and processing wastes. Until such a policy has been established, the future for el ectrotechnol ogy appl ications is uncertain.

5-11 REFER E NCES

1. "Nuclear Waste Management Status and Recent Accomplishments". EPRI, 1979.

5-12 Section 6

RESOURCE RECOVERY

BACKGROUND

The Resource Recovery Act of 1970 and the Resource Conservation and Recovery Act of 1976 together have resulted in a shift of emphasis in waste disposal techniques from that of land application and non-productive methods to processing and resource recovery.

The tightening regulations on municipal landfills in combination with siting problems and lack of additional landfill space have forced many cities and counties in the United States to reexamine the option of resource recovery, which is the transmutation of waste into usable products and energy.

One of the direct results of the new laws can be seen in the increased number of waste material wholesalers. The nation's 81,043 such businesses had sales of $12.8 billion 1982, with metal and metal scraps accounting for close to 80% of the total sales. These figures are up from the sales of $10.4 billion for 7,428 establish- ments in 1977. Figures 6-1 and 6-2 illustrate the growth in recycling in the period between 1965 to 1984, and Table 6-1 presents the total quantities of recycled materials in the United States in 1984. The energy savings realized by recycling of waste materials is illustrated by Table 6-2.

WASTE REDUCTION

There are many important incentives for industry in the consideration of recycling, resource recovery, and waste reduction at the source. These incentives include minimizing the cost of disposal by reducing the quantities of waste, and maximizing profits by conservation of strategic materials.

According to the Congressional Budget Office, the quantity of hazardous waste generated in the U.S. could rise about 5% from 1983 to 1990, if no waste reduction techniques are empl oyed by industry. On the other hand, if all of the waste

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u ci,

0 0 0 03 <9 d-

6-3 Table 6-1 TOTAL QUANTITIES OF RECYCLED MATERIAL (U.S., 1984) (million MT)

~ ~~ Approx. Quantity Material Total Consumed Recycled Percent of Total of Electricity U.S. ConsumDtion Consumed

Aluminum 5.9 1.76 30 670 Copper 3.0 1.6 54 480 Ferrous metals 110 38.7 35 12,000 Glass 10.4 1.05 10 390 Paper 70.6 16.9 24 11,700 Stainless steel 1.1 0.5 45 190 0.l Lead 0.6 53 12 I 1.1 P

If Recycling Increases 5%, Electricity Consumption Increases 1,250 Million kWh

MineraVMining Waste

Over 2 billion tons of solid waste generated annually. Disposal mostly by land applications and landfills. Some utilization as building materials in construction industry.

I li I Table 6-2

ENERGY SAVINGS THROUGH RECYCLING OF WASTE MATERIALS

€ne gy Savings Percent 106 Btu/Ton Savings 1 Est. 2 Range3 Est.' Range3

Ferrous Metals 15.5 7.0-42.2 65 50-74

A1 umi num 224 169-281 92 92-97

Copper 94.7 40.3-94.7 85 84-95

Lead 17.5 5.5-17.5 65 56-65

Zinc 39.3 11.8-47 .O 60 60-72

Paper/ News paper 35.5 5.2-35.5 64 23-70

G1 ass - 1.3-2.5 - 0-14

Rubber 22.1 22.0-22.1 71 11-18

Data compi 1 ed by JRB Associates.

'Realized savings resulting from use of recycled materials as compared with total energy expended in refining new materials.

'From the National Association of Recycling Industries.

3Estimated range from various sources.

Source: Ref. 1

6-5 reduction incentives incorporated in the RCRA 1984 amendments were taken, the quantity of wastes could be reduced from 266 MMt in 1983 to as low as 229 MMt by 1990, a 14% reduction.

A breakdown by industry type of the sources of the reduction in generated hazardous wastes is shown in Table 6-3. In order of decreasing effect, the industries contributing the most to this reduction would be:

0 fabricated metal products 54%

0 petroleum and coal products 19%

e electrical and electronic machinery 19%

0 motor freight transportation 15%

0 primary metals 13%

All of these industries produce a high proportion of liquid wastes, which are easier to reduce than sludge or solid wastes.

One measure of the effect of the 1984 RCRA amendments on industry is the percentage of profits spent on the added cost of compliance (Table 6-4). The wood preserving industry is estimated to need up to about 111% of the profits made in 1990 in order to manage wastes without using any waste reduction measures. If waste reduction techniques are used, however, the estimate decreases substantially to 16%. Other industries whose profit margins will narrow with the implementation of the new regulations are primary metals, rubber and plastic products, chemicals, and petroleum.

Industry can react to the 1984 Amendments' prohibition on land disposal by using more expensive disposal methods, employing waste and water-reduction techniques , or by not complying. A combination of the three options will invariably occur, although it is difficult to predict which will be most prevalent. Assuming that industry does comply with the new regulations and that EPA will meet all of the RCRA deadlines, a comparison can be made between the quantities of waste that are predicted to be generated depending on whether waste reduction practices are or are not used.

6 -6 Table 6-3

ESTIMATED CHANGES IN WASTE GENERATION PATTERNS 1983 and 1990, by Major Industry Group, under A1 ternative Cases (In thousands of metric tons)

1990 1990 Percent Quantity Quantity Change in Quantity With No With 1990 from in Waste Waste Waste Major Industry 1983 a Reduction Reduction Reduction

Chemicals and Allied Products 127,245 136,678 115,167 -9 Primary Metals 47,704 49,597 41,611 -13 Petroleum and Coal Products 31,356 29,213 25,526 -19 Fabricated Metal Products 25,364 25,493 11,820 -54 Rubber and Plastic Products 14.600 17,954 17.252 + 18 Miscellaneous Manufacturing 5,614 5,856 5,001 -11 Nonelectrical Machinery 4,859 5,717 4,831 -1 Transportation Equipment 2,977 3.243 2.781 -7 Motor Freight Transportation 2,160 2,160 1,836 -15 Electrical and Electronic Machinery 1,929 2,313 1,557 -19 Wood Preserving 1,739 2,095 1,743 0 Drum Reconditioners 45 45 16 -64

Total 265,595 280,364 229,141

Percent change from 1983 +5.6 -13.7

SOURCE: Congressional Budget Office

a. Mean estimate of waste generation under pre-1984 RCRA policies (see Table 3 in Chapter 11).

b. Assumes no waste reduction efforts by industry in response to 1984 RCRA amendments. Projection of waste generation levels in 1990 based on growth in industrial output levels forecast by the CBO generation model. Decreases in waste quantities therefore result from declining levels of industrial (and waste-producing) activity. c. Assumes waste-reduction efforts by industry, as detailed in Table 11. Forecast includes waste growth from increases in industrial output identical to that of the higher 1990 waste-reduction case.

Source: Congressional Budget Office, May 1985.

6-7 Table 6-4

ESTIMATED INCREMENTAL HAZARDOUS WASTE MANANGEMENT EXPENDITURES UNDER THE 1984 RCRA AMENDMENTS As a Percent of Estimated 1990 Profits By Major Industry Group, Under Alternative Cases

Without With Waste Waste Major Industry Reduction a Reduction

Wood Preserving 111 .o 15.6 Primary Metals 64.2 25.3 Rubber and Plastic Products 52.3 41.4 Chemicals and Allied Products 44.6 20.9 Petroleum and Coal Products 33.8 20.9 Fabricated Metal Products 28.1 C Miscellaneous Manufacturing 8.7 4.0 Electrical and Electronic Machinery 3.2 C Transportation Equipment 2.9 1.6 Nonelectrical Machinery 1.9 1 .o Drum Recondi tione rs C C Motor Freight Transportation d d

SOURCE: Congressional Budget Offce, based in part on profit to sales ratios found in Dun and Bradstreet,Industry Ratios and Financial Norms (1983 - 1984) edition.

a. Projection based on no waste reduction case in Table 12. b. Projection based on waste reduction case in Table 12. c. Less than 1 percent. d. Profit to sales data are not available.

Source: Congressional Budget Office, May 1985

6-8 Table 6-5 lists the predicted fraction of wastes by waste type for those which can be reduced. Cyanide and metal-containing liquids are at the top of the list, with a potential of about 70% reduction each. Table 6-6 lists reverse osmosis, evaporation, and ion exchanges as common methods available to recover materials and reduce the water content of the contaminated liquids.

Another method available to reduce the amount of waste subject to disposal regulations is to substitute non-hazardous compounds in waste-produci ng processes for hazardous materials; for example, the use of open air-cooled transformers or oil-filled transformers in place of those containing PCBs.

In the following sections, several areas of resource recovery will be reviewed.

CRYOGEN IC RECOVERY PR OCESS I NG The use of cryogenics in reclamation processing has also been found to be practical in the recovery of ferrous and non-ferrous metals from scrap automobiles, in reclaiming copper from electrical wire, and in the processing of plastic scrap. Both the production and use of the cryogenic liquid in these reclaiming processes are highly electric-power intensive.

In the plastics and rubber industries cryogenic systems have been used and marketed for over 20 years (2).Deflashing of rubber molding and freeze grinding of plastics and rubbers with cryo-systems is commonplace. The deflashing process uses liquid nitrogen (LIN) to cool a material below its embrittling point. For instance, the excess rubber left on moldings during the molding process is bathed in LIN and then the frozen "flash" is removed through grinding. The procedure then uses impact mills to reduce these free, brittle granules to a fine powder, often with the addition of liquid nitrogen directly to the mill in order to keep the granules sufficiently britt1e.

Total systems for cryogrinding of plastics are marketed by several companies, including Airco, Inc., Industrial Gas Division; Liquid Carbonic Corporation; Air Products and Chemical Inc.; and Union Carbide, Linde Division (3).-

The use of cyrogenics for scrap processing requires rapid cooling of the material below the embrittlement point for one of its constituents. In this way, the process can be used to separate the different materials of a component. For instance, the plastic insulation can be easily removed from copper wire by freezing the insulated

6 -9 Table 6-5

ESTIMATED CHANGES IN WASTE GENERATION PATTERNS 1983 and 1990 Ranked by Waste Quantity, under Alternative Cases (In thousands of metric tons) 1990 1990 Percent Quantity Quantity Change in Quantity With No With 1990 Due in Waste Waste to Waste Waste Type 1983a Reduction Reduction' Reduction

Nonmetallic Inorganic Liquids 82,261 a9.908 71.705 -12.8 Nonmetallic Inorganic Sludge 28,061 28,177 26,768 -4.6 Nonmetallic Inorganic Dusts 21,120 22,214 19,993 -5.3 Metal-Containing Liquids 19,760 19,983 5,995 -69.7 Miscellaneous Wastes 15,415 16.759 15,921 +3.3 Metal-Containing Sludge 14,497 15,147 13,632 -6.0 Waste Oils 14,249 13,932 11,842 -16.9 Nonhalogenated Solvents 12,130 11,869 10,682 -11.9 Halogenated Organic Solids 9,784 11,558 11,558 +ia.i Metallic Dusts and Shavings 7 733 8.112 6,a95 -10.8 Cyanide and Metal Liquids 7,383 7,284 1,821 -75.3 Contaminated Clay, Soil, Sand 5,461 5,748 5,748 +5.3 Nonhalogenated Organic Solids 4,578 5,227 5,227 +14.2 Dye and Paint Sludge 4,236 4,112 3,086 -27.1 Resins, Latex, and Monomer 4,018 4,586 4,357 +8.4 Oily Sludge 3,734 3,556 3,200 -14.3 Halogenated Solvents 3,479 3,a03 3,423 -1.6 Other Organic Liquids 3,435 3,755 2,817 -18.0 Nonhalogenated Organic Sludge 2,242 2,478 2,478 +10.5 Explosives 7 20 a21 780 +a.3 Halogenated Organic Sludge 715 683 683 -4.5 Cyanide and Metal Sludge 557 593 505 -9.3 Pesticides, Herbicides 26 28 24 -7.7 Polychlorinated Biphenols 1 0.0

Total d 265,595 280,364 229,141

Percent change from 1983 -_ +5.6 -13.7

SOURCE: Congressional Budget Office. a. Mean estimate of waste generation under previous RCRA policies (see Table 3 in Chapter 11). b. Assumes no waste reduction efforts by industry in response to 1984 RCRA amendments. Projection of waste generation levels in 1990 based on growth in industrial output levels forecast by CBOs generation model. Decreases in waste quantities therefore result from declining levels of industrial (and waste-producing) activity.

C. Assumes waste-reduction efforts by industry, as detailed in Table 11. Forecast includes waste growth from increases in industrial output identical to that of the higher 1990 waste- reduction case. d. Columns may not add to totals because of rounding.

Source: Congressional Budget Office, May 1985.

6-10 Table 6-6

ESTIMATED TARGETS FOR WATER REDUCTION AND MATERIAL RECOVERY THROUGH IMPROVED INDUSTRIAL PROCESSES

Water Material Recovery Potential Red uc t i o n Target- Target Material Recovery Waste Type (percents) Recovered Process (percents)

Liquids Waste Oils 0 lubricating rerefining oil Halogenated Solvents 0 solvents distillation Nonhalogenated Solvents 0 solvents distillation Other Organic Liquids 5 organics steam stripping Metal -Containing Liquids 40 metals ion exchange1 evaporation Cyanide and Metal Liquids 50 cyanide1 reverse osmosis1 metal solution evaporation Polychlorinated Biphenols 0 none -- Nonmetallic Inorganic Liquids 20 none Sludges Oily Sludge 0 crude1 coker recycle distillates Halogenated Organic Sludge 0 none __ Nonhalogenated Organic Sludge 0 none -- Metal -Containing Sludge 5 metals varies Cyanide and Metal Sludge 5 metals varies Nonmetallic Inorganic Sludge 5 none -- Dye and Paint Sludge 5 solvents ultrafiltration Solids Contaminated Clay, Soil, Sand 0 none __ Metallic Dusts and Shavings 0 metals magnetic sepa- ratio nll eachi ng Nonmetallic Inorganic Dusts 0 sulfur sulfur recovery Halogenated Organic Solids 0 none __ Non halogena ted Organic Solids 0 none __ Mi xed Pesticides. Herbicides 10 organics solvent extraction Explosives 5 none __ Miscellaneous Wastes 5 none __ Resins, Latex, and Monomer 0 resinsllatexl isolation and monomer process return

SOURCE: Congressional Budget Office, based on literature cited in CBO, Empirical Analysis. a. Note that water reduction does not necessarily reduce the risk of environmental contamination. By reducing water use, industry can reduce waste management costs, but residuals for final disposal might be concentrated. Reduction potential could be even greater if individual companies devise innovative, plant-specific reduction measures. Source: Congressional Budget Office, May 1985.

6-11 wire below the embrittlement temperature of the insulation, yet above the embrittlement temperature of the copper. Once this temperature has been reached the brittle insulation can easily be removed from the ductile wire.

Cryogenics can also reduce the operating costs for recycling materials. When a material is no longer ductile it can be milled, ground, or shredded with much less horsepower. A difficult-to recycle item such as an auto tire can be reduced to crumb particles after it is embrittled by LIN.

Liquid nitrogen is the most commonly used cryogen for cooling materials for recycling. LIN has a boiling point -196'C (-320.8"F) low enough to cool many material below their embrittlement temperature. Initial work in cryogenic scrap processing was conducted using dry ice, liquid CO2, and liquid nitrogen; it was soon deduced that the most practical and economical method of cooling was affected with liquid nitrogen (4).- The coolant being in a liquid form can also aid in the heat transfer. When a material is initially immersed in LIN nucleate boiling often occurs, resulting in high heat transfer rates.

Liquid nitrogen is produced in a vapor-compression refrigeration system. Large nitrogen liquifaction plants separate nitrogen from the air and liquify it while consuming 0.84 to 1.2 kWh/kg (0.38 to 0.54 kWh/lb) LIN produced (5). Although these plants can produce large quantities of LIN at low cost (about $0.077/kg, or $0.035/ lb), a cryogenic recycling system's need for LIN is not great enough to justify the construction of a merchant nitrogen liquifaction plant because of the high capital costs.

The techniques for cryogenic reclamation of auto and truck tires, car scrap, and electrical wire are described in the following sections. Furthermore, the economics of current methods versus cryogenic techniques wi 11 be discussed.

Auto and Scrap Tire Processing

Auto and truck tires are excllent candidates for cryogenic recycling. More than 250 million tires are discarded each year in the United States. Currently only about 30% of these will be recycled in some way (15 to 20% recycled by retreading; 10 to 15% reclaimed for production of fuel, heat, or other rubber products), which results in approximately 180 million used ti res being disposed of non-productively each year. Most of these tires are shredded and buried in landfills.

6-12 The energy recovery processes currently available for disposal of scrap ti res include pyrolysis and incineration with energy recovery. The energy recoverable from incineration makes this process attractive as a disposal technique. Scrap tires have a heating value on the order of 15,000 Btu/lb as compared with approximately 12,500 Btu/lb for coal, and generally have a lower sulfur content than coal as well. Three basic designs have been proposed for whole tire incineration: batch, inclined rotary kiln, and rotating hearth with cyclonic gas flow. Batch and inclined rotary kiln processes can accept either chipped or whole tire feed; rotary hearth incinerators require whole tires as feed material.

Pyrolysis of scrap tires to produce gases, light and heavy oils, and carbon black has been researched by various companies including Coodyear Tire and Rubber Company and Firestone Rubber Company.

A typical cryogenic grinding system is depicted in Figure 6-3. In this system scrap tires are first granulated in a mill at ambient temperature. The rubber chips are then cooled in a conveyor by LIN, and this is followed by high impact with a grinding mill which reduces the embrittled rubber to fine, powdery rubber, bits of fabric, and metal from the steel belts in the tire. Particles as small as 75 microns can be obtained. The steel and fiber can then be separated by magnetic and gravitational methods. The process is carried out in a nitrogen atmosphere (gaseous LIN) , thereby avoiding fire or explosion risks and harmful oxidation effects during elevated temperature conditions.

Crumb rubber produced cryogenically has several uses, including a range of molded and extruded rubber products such as irrigation hoses, garbage cans, and flower pots (a). It can also be incorporated into virgin rubber compounds and into asphalt. Crumb rubber has been mixed with asphalt binders for road surfaces with very positive effects; the mixture results in raising the softening temperature of asphalt, thus allowing less flow at high temperatures. At the same time asphalt's brittle point is lowered, so that cold weather is less likely to crack the road.

The major operating cost for producing crumb rubber of a 30-mesh particle size is the cost of the liquid nitrogen itself. The nitrogen consumption necessary to cryogenically process auto and truck tires is about 1 kg nitrogen/kg rubber. Thus, the LIN cost exceeds $70 per ton of rubber. The current demand for crumb rubber is very slight, and the best selling price available is only $60/ton, or 14.3% less than the cost of the LIN alone.

6-13 I-

Figure 6-3. Cryogenic Grinding System

6-14 Cryogenic recycling is not an economically feasible waste reclamation method, however, if the problem is viewed as one of waste disposal, then cryogenic processing of vehicle ti res becomes an attractive possibility. Currently the present disposal met hods such as 1 andf i11 , compost ing , ocean dumping , and incineration are more economical than cryogenic recycling and thus very little rubber is recycled. (L)

Scrap Automobiles. The modern automobile is made up of many different materials intertwined around a mild steel framework. The present-day car is composed of about 653 kg (1,400 lbs) steel; 12.7 kg (28 lbs) cast iron; 9 kg (20 lbs) copper; 13 kg (30 lbs) zinc; small amounts of tin, lead and aluminum; and 90 kg (200 lbs) of rubber, plastics, and other materials (8).-

The most efficient method of recovering these elements begins with sorting the different materials from one another. It is important not to mix some elements in the reclamation effort, or further problems will arise. For instance, non-ferrous contaminants in steel will limit its usefulness and value to the steel processor. Furthermore, these contaminants can be reclaimed and sold at higher prices if they are first isolated.

The current method for reclaiming the metal scrap from auto bodies is to remove all of the non-metallic components manually and then to crush the body into a bale. The bale is subsequently shredded and the ferrous and non-ferrous metals are separated by magnetic and manual means. This process is difficult, labor-intensive, and costly since the shredder yields pieces with multiple folds which can easily entrap significant amounts of contaminants in the ferrous material.

Since the cryogenic process cools and embrittles the material before it is shredded, the material shatters rather than folds. Flat, coin-sized fragments are produced without folds or voids to entrap contaminants, thus solving a major problem with the current t ec hnol ogy .

A cryogenic process known as "inch scrap'' (Figure 6-4) was developed in Belgium by the Robert George Co. and enables the processing of whole cars--complete with engine, transmission, tires, and interior trim. Labor costs associated with stripping the car, necessary with conventional methods, are reduced with the use of this new process.

6-15 1) Steel bales 8) Cryogenic tunnel - precooling section 16) Shredder motor 2) Assorted scrap 9) Cryogenic tunnel - immersion section 17) Steel turnings 3) Carbodiis 10) Liquid nitrogen feed pipe 18) Clean air outlet 4) Sheets and coils 11) Liquid nitrogen storage vessel 19) Conveyor belt for the steel shards 5) Hydraulic or mechanical press, mobile 12) Tunnel exit door 20) Large non-ferrous parts and waste material or fixed compressive directions 13) Mechanical or hydraulic feeder 21) Non-ferrous particles 6) Gaseous nitrogen outlet 14) Roller table 22) Magnetic separator 7) Counter-current flow of nitrogen 15) Shredder 23) Cryogenic scrap

Figure 6-4. Inch-Scrap Method

.! In this process the car is compressed into a 600 x 600 mm (24" x 24") cross-section bale of variable length and a density of about 2 kg/m3 (0.12 lb/ft3), which is then cryogenically cooled to about -120°C (-184°F). This baler is the same as that used in conventional methods, although the whole car can be processed when the inch scrap method is being utilized. After baling, the compressed car is transferred into the cryogenic cooling tunnel. This next step is the one major difference between inch scrap processing and conventional methods.

Moving on rails, each bale enters the tunnel and is pre-cooled by cold nitrogen gas to about -7°C (19"F), after which it contacts liquid nitrogen in a shallow bath gas boiling-off nitrogen gas. The bales continue to be cooled with LIN while still in this tunnel. The optimum cooling temperature of about -120°C (-184°F) is particulary desirable because steel, iron, zinc-based die-cast a1 loys, plastics, and rubber will all be brittle, while copper, aluminum, and lead will remain ductile and will not shatter in a hammer mill (I).

Once cooled, the bale quickly enters the hammer-mill shredder where the ferrous particles are broken into coin-size pieces while the aluminum, copper, and fabric materials remain in large pieces. Large and sma 1 particles are easi y separated by a grating. This shredder has a conventional design but requires only 1/10 the horsepower that is necessary for a non-cryogenic system.

The small pieces are then transferred by belt to a magnetic separator to sort out the ferrous from the non-ferrous materials and contaminants such as plastics and rubber. The product is a ferrous scrap comprised mainly of pieces of about 30-mm (1.2 inch) in length and a density of 2000 to 3000-kg/m3 (125 to 187 lb/ft3), and is highly marketabl e.

There are three main advantages in using the inch-scrap system:

0 A high degree of purity is achievable in the steel scrap due to the 1 ow-level entrapment of contaminant material.

0 There are lower capital and operating costs for the shredder since the power requirements necessary to shred brittle metal are about 1/10 of that required with other processes.

0 Safety is increased since the nitrogen atmosphere in the shredder minimizes any chance of an explosion.

6-17 Even though the commercial feasability of the inch-scrap process has been amply demonstrated--a plant has been operating in Belgium since 1971 which is capable of processing 20,000 kg/hr (22 tons/hr) of baled automobiles--the process has not yet been adopted by any American scrap processor.

Nonetheless, an economic comparison between plants using each of the processes wi 11 reveal that conventional reclamation methods are still more profitable than the inch-scrap method. The economic advantages of a cryogenic system, namely the reduced cost for shredding and higher quality output, do not offset the high cost of the liquid nitrogen.

It should be noted that the fixed costs of the two systems are essentially the same (the higher shredder cost for the non-cryogenic system is balanced by the additional cost of a baler screen separator and cryogenic tunnel). Therefore, all costs common to both systems (e.g., fixed capital costs such as land and service facilities; and insurance and taxes) are not considered; only the cost and revenue differences between the two systems are documented.

The cost basis rests on dollars per ton of scrap input, and assumes a 60-ton/ hr processing rate and 2080-hr/yr operation. The fixed costs on a per ton input basis are $2.23 and $2.93 for a non-cryogenic and a cryogenic system, respectively.

It is clear, then, that the operating costs are what make the cryogenic system unattractive. The savings in electricity and the higher value of more pure scrap together add only about $2.50 per ton to the yield of a cryogenic system, and still do not offset the high liquid nitrogen costs of $26.50/ton of input.

In summary, the higher operating costs of the cryogenic system are not balanced by the only slightly higher revenue of this process. The higher operating costs are primarily due to the cost of liquid nitrogen and only a reduction in the price of this material would make a cryogenic auto scrap reclamation system more attrative.

Electrical Wire. Miles of wire scrap are produced in the wire manufacturing process every year. Taken together with the metal-bearing wire and cable discarded annually, this represents a significant resource available for reclamation. The copper or aluminum metal conductors can be reclaimed after removing the polyvinyl chloride or nylon-coated polyethylene insulation from the wire.

6-18 Currently, two methods are used. The first burns off the insulation, leaving an oxidized layer on the wire; the other removes the insulation by chopping and grinding the composite wire into approximately 1/8" pieces, and the metal and insulation are separated by flotation. Unfortunately, the conductor is damaged with either of these methods and cannot be reprocessed directly. Eventually, however, about 97-99% of the available copper can be reclaimed, and can be sold for about $1.08/kg ($1080/ton).

A cyrogenic system can remove the insulation from the wire without any damage, leaving a bare conductor which can be immediately reprocessed and reclaimed. The plastic insulation typically used on copper wire can be easily removed by freezing it below the plastic's embrittlement point and then shattering it. The insulation can then be separated from the copper with either an air or water stream. Due to the different properties of the elements, copper's embrittlement point is considerably lower than the temperature to which the wire is subjected, and so the metal remains ductile and whole.

A simple prototype design has been fabricated by Professor S.L. Rice of the University of Connecticut, as shown in Figure 6-5. This system winds wire on a take-up spool driven by an electric motor pulling the wire from a pay-off spool running through a tank containing LIN. The insulation is embrittled at temperatures ranging from -11°C to -110°C (12°F to -126'F), at which point the wire can be seen as a brittle tube of thermoplastic covering a ductile metal core. After leaving the cryogenic bath, the wire passes through break-off rollers which subject it to tensile bending stresses. The brittle insulation thus fails while the ductile metal bends, and the plastic falls away from the copper. The result of this process is a bare conductor, stripped clean of its insulation. The LIN usage for the process is on the order of 1.62 kg/kg of product metal.

A cryogenic system has two advantages: first, that the copper wire output need not be chopped and can be immediately reused. Furthermore, very fine wire can be processed with the cryogenic system, whereas the current chopping method is unable to separate smal 1-diameter wire from its insulation. The disadvantage to cyrogenics is of course the LIN cost, about $0.13/kg of metal recovered. Unfortunately, the additional cost is not offset by any market advantage as the present market for whole wire is saturated and the market for fine wire is not sufficiently large.

6-19 6-20 RECYCLING & RECOVERY PROCESSING OF ELECTRIC ARC FURNACE DUST

Electric arc furnaces (EAF) are gaining in popularity among both minor-market mills and the larger producers of steel due to their lower capital cost and shorter planning and construction requirements. Presently, electric-arc furnaces account for approximately 40% of the steel output in the United States.

In the EAF 1 to 2% of each charge is converted to dust and fumes, which are collected in scrubbers or baghouses. The chemical composition of the dust depends on the type of steel being made (Table 6-7). EAF dust resulting from production of carbon steel tends to be rich in zinc and lead because of the use of galvanized and other coated products in the melt. In 1980, the Environmental Protection Agency (EPA) classified electric arc furnace dust as a hazardous waste (EPA-assigned hazardous waste number K601) , primarily due to its toxic consituents (Pb, Cd, Cr).

As a hazardous waste, the dust must be chemically stabilized so that it can be 1 andfil led as non-hazardous waste , or transported to an EPA-approved hazardous waste site. Consequently, controlled landfill disposal has become a costly affair, with the disposal cost at EPA-approved sites today being ten times or more the cost of disposal at non-hazardous sites before 1980. It is estimated that the cost of landfilling EAF dust could reach as high as $ZOO/ ton by the end of 1986.

Despite the escalating cost of land disposal , 73% of the estimated 500,000 tons of EAF dust generated annually in the United States is still being landfilled. However, EPA has set August 8, 1988 as the deadline for banning the land disposal of the dust, provided suitable treatment technology is available. The steelmaking industry, has thus begun to look for other viable alternatives for handling the dust.

Electric arc furnace dust represents the potential for a source of valuable elements such as iron and zinc, the recovery of which appears to be a logical alternative to the disposal problem. Such recovery of non-ferrous elements from EAF dust could additionally result in a residue that has been sufficiently detoxified for disposal in a landfill or recycling to the furnace for the further recovery of iron.

As shown in Table 6-7 the average zinc content of EAF dust for carbon and low-alloy steel production is about 19%. Therefore, based on the representative generation rate of 500,000 tons dust/year, the quantity of zinc available for potential recovery is approximately 100,000 tons znlyear. These figures reveal that the zinc recovered from EAF dust has the potential of providing close to 10% of the total

6-21 Table 6-7

CHEMICAL COMPOSITION OF DUST FROM ELECTIC ARC FURNACES

Stainless Steel and Specialty Carbon and Low-A1 1oy Steel s A1 1oys

Element Wt %a Range, % Element Wt %b Range %

A1 0.25 0.09 - 0.53 A1 0.40 0.20 - 0.60 Ca 4.19 1.85 - 10.0 Ca 3.91 1.76 - 6.93 Cd 0.05 0.08 - 0.15 Cd 0.46 0.006 - 1.79 Cr 0.22 0.06 - 0.58 Cr 5.88 2.01 - 10.1 cu 0.23 0.06 - 0.32 cu 0.62 0.09 - 1.26 K 0.66 0.06 - 1.12 K 2.07 0.80 - 5.07 Mg 1.68 0.77 - 293 Mg 3.78 1.70 - 4.74 Mn 3.29 2.46 - 4.60 Mn 3.72 2.36 - 4.59 Mo 0.02

so4 0.70 0.01 - 0.88 a Arithmetic averages of dust from seven plants. Arithmetic averages of dust from four plants.

Source: Ref. 9

6-22 annual consumption of zinc in the United States. However, an EAF dust zinc content of 20% or more is required to make the recycling or recovery economical , given the technology currently available.

For dusts with low zinc content (4-5%), chemical fixation and stabilization of the dust followed by landfilling as a non-hazardous waste is the most economical option. Two alternatives are available to EAF operators for recovery processing of the dust. The first option is to transport the dust to an off-site regional processor to upgrade the zinc content of the dust or produce metallic zinc. The second alternative is on-site processing by either direct recycling of the dust back through the furnace or by utilizing a separate process to upgrade the zinc content of the dust to about 20%, or even to produce metallic zinc. The promising technologies for off-site or regional processing of dust are Waelz kiln, HTR (Himezi Tekko Rifian KK) kiln, and SDF Steel Plasmadust.

Waelz Kiln

The only regional EAF dust processing plant in the United States is New Jersey Zinc's Waelz kiln operation at Palmerton, Pennsylvania. This plant processed over 50,000 tons of dust with greater than 20% zinc content in 1985, and the quantity of EAF dust processed annually is expected to reach 150,000 tons in 1986. The product of the kiln operation is a dust with an upgraded zinc content of >50% in the form of zinc oxide.

The EAF dusts arriving from various sources are mixed to reduce variations and then combined with limestone and anthracite coal. This mixture is subsequently heated to 13OO0C, at which point the zinc and lead oxides are reduced to metal vapors. These metallic vapors reoxidize quickly as they flow countercurrently to solid flow, and the exothermic heat of their reoxidization helps to reduce the fuel requirements of the process. The kiln gases are withdrawn at the feed end and are cooled by air dilution and finally collected in baghouses. The collected dust which typically contains 50 to 55% lead is conveyed to the sinter plant to produce the final zinc oxide product.

The St. Joe Mineral Company's electrothermic smelter in Monarch, Pennsylvania is the sole domestic market for these upgraded EAF dusts.

6-23 The residual slag, which contains 30 to 40% iron, cannot be recycled to EAF economically; however, it can be landfilled as non-hazardous material. The fees charged by New Jersey Zinc vary with the zinc content of the dust, presently ranging from $30 to $40/ton of dust.

HTR Kiln

The HTR process is a modified version of the Waelz kiln operation that requires less power than the conventional kiln. The HTR kiln operation philosophy is based on a relative reduction concept whereby the zinc oxide is reduced to metallic zinc and then reoxidized, thus concentrating the metal. In this process, furthermore, the reduction to metallic iron of the iron oxides in the primary dust is minim zed through temperature control in the kiln. The iron oxides are discharged with the non-hazardous slag and qualify for non-hazardous disposal .

Currently, the HTR kiln process is being used by four steel manufacturers in Japan who report' that the smallest facility which would be economically feasible to operate would have the capacity of treating 40,000 tons of dust annually.

The HTR and Waelz kiln operations are not electric energy intensive, with electricity requirements ranging from 40 to 45 kWh/ton of dust processed. However, there is a limited market for their upgraded dust product.

SKF P1 asmadust

The SKF P1 asmadust process is an electrical energy-intensive process using three 6- MW pl asma arc-heaters , wi th an electrical energy requirement of approximately 1900- kklhlton of dust. In this process a feed which consists of untreated dust, coal powder, and process gas that has been preheated to about 350OOC in a plasma arc is fed into the Tuyere level of a shaft furnace. Coke fills the shaft from the top and an endothermic reaction follows.

High-carbon, hot metal collects at the bottom as zinc and lead vaporize and exit the shaft at the top along with the off-gases, and are collected in a separate condenser.

The SKF process has been commercialized in Sweden and a plant capable of processing 80,000 tons dustlyr is currently operational. This plant processes dust containing >20% zinc and produces prime Western-grade zinc valued at $0.45- $0.50/lb.

6-24 The capital cost for installing a similar plant in the U.S. has been estimated at $40 million.

On-Site Processing of EAF Dust

Recycling. The use of this methodology may consist of returning the dust to EAF as part of the scrap charge in the form of either briquets or green balls. (The process is commonly called "greenballing" because of the appearance of slightly moist balls formed when water is used as a binder.) Or, the dust could be injected directly into the melt.

Recycling has the advantage of using existing equipment; however, it could interfere with normal EAF operations. For instance, the addition of recycling to the furnace would increase the energy consumption for the EAF at the rate of 10 to 30 kWh/ton of steel. Still, there are a number of solutions available, including the use of direct current furnaces that use 3.3% less electrical energy than the standard AC furnaces.

It has been proposed that the EAF dust be recycled as a means of increasing the zinc concentration in order to reach the 1540% zinc content required to make recovery operations economical. Recycling would also return iron and slag to the melt which of course would decrease the dust accumulation rate. The cost of constructing and operating a recycling facility for a large EAF shop (>go00 tons of dust produced annually) is estimated by Babcock & Wilcox at $40 to $60/ton of dust.

Economics aside, many questions regarding the use of direct recycling as the first step in processing EAF dust remain unresolved. Dust recycling, for example, can result in the buildup of tramp elements in the steel and slag that otherwise would have been removed in the dust stream.

Recovery Processi ne

Processing the EAF dust in separate, on-site facilities has the advantages of not interfering with normal EAF operations, a greater ability to produce secondary dust with better than 50% zinc content, or even the possibility of producing metallic zinc. The promising technologies currently available or under development for On- site recovery processing of EAF dust include the plasma-arc reactor, selective reduction process, and the high-temperature fluid-wall reactor.

6-25 P1 asma-Arc Reactors

Plasma-arc reactors are suited for on-site processing of EAF dust because of their ability to process fine solids. Furthermore, metallic zinc rather than upgraded zinc oxide dust can be produced through controlling the gaseous atmosphere in the reactor (by using argon or nitrogen). In order to process between 5,000 and 6,000 tons of EAF dust annually it is estimated that a 1-MW plasma reactor would be ~ requi red.

Various plasma reactor designs by companies such as Tetronics R&D and Tibur Metals have been operated on EAF dust with pilot-plant trials of 1-MW, the capital cost of which is estimated at $1.5 million. This system would require approximately 1000- kWh/ton of dust treated.

Selective Reduction Process

In this ‘type of process only the zinc oxide is recovered, leaving iron oxide in the gangere. St. Joe Mineral Company is currently developing a system capable of processing 2000 to 5000 tons of dust/year based on their 20,000 tons of dustlyear slag fuming operation in Monaca, Pennsylvania. The estimated capital cost for a 2000 to 5000 Tons/year system is $1 million.

High-Temperature F1 uid-Wall Reactor

The high-temperature fluid-wall reactor developed by Thagard Corporation of California operates through radiation heating of the EAF dust in order to vaporize the zinc and lead and recover these elements in their metallic form. Six graphite resistance electrodes are utilized to produce radiation intensities of approximately

200 w/cm2 and temperatures on the order of 4000OF. Thagard Corp. is currently ~ operating a pilot plant in Oakland, California. The estimated capital cost for a system capable of treating 5000 tons of EAF dust/year is $1.5 million. Such a system would utilize approximately 400 kWh/ton of dust treated.

In general, on-site processing of EAF dust has the advantage of saving the EAF operation the transportation and disposal costs involved in using a regional facility. In addition, income can be generated through the production of a salable c ommod ity .

6-26 RECOVERY OF METALS FROM WASTE SLUDGES

The metal finishing industries generate significant amounts of waste metals in the form of metal oxide sludges. The accumulation of these wastes poses disposal problems for these industries. However, there is also a potential for recovery of strategic metals with significant value from these sludges.

The main objectives to be achieved through the recovery and recycling of metals from the wastewater of mineral and metallurgical process industries are to accomplish the fol 1 owing :

0 Minimize the uncontrolled emissions of metals in water soluble form into water resources.

0 Conserve strategic materials.

0 Lower the cost of hazardous waste disposal.

At the present time significant amounts of waste metal sludges are being stored on- site by individual companies; however, accurate quantitative information is not readily available regarding their exact composition and metal content,

The technologies currently available and applicable to recovery processing of metal- containing waste effluents include precipitation, ion exchange, reverse osmosis, flotation, and electrodialysis. The use of primary physical separation procedures such as evaporation, sedimentation, centrifugation , floccul ation, and fi1 tration for recovery of metal oxides offers poor prospects for recovering marketable materials. The low cost of precipitation makes it attractive for recovery processing; however, as is the case for the physical separation methods, the materials recovered have low market value.

F1 otation

Flotation is a promising technology which is applicable to both soluble and insoluble metals. The use of certain anionic surfacants, notably sodium lauryl sulfate (NLS) and petroleum sulfonates, can be effective in non-selective flotation separation and recovery of mixed metal hydroxides from plating and electrochemical milling waste sludges. The use of NLS is especially effective in enlarging particle size, and as a result flotation efficiencies are enhanced.

Detailed descriptions of flotation, reverse osmosis, ion exchange, and electrodialysis processes are included in Section 4.

6-27 RECYCLING OF CANS AND BOTTLES

The once-popular tin cans, which in reality were made of steel with a tin coating, have been edged out by aluminum cans and plastic containers. Aluminum is lead-free, almost rust-proof, light, and both easy and economical to recycle.

.~ Currently, more than one fourth of the total U.S. annual production of aluminum is used in the manufacture of packaging; one half of this is used by the beverage industry. More than 92% of the beer and soft drinks sold in the U.S. are packed in aluminum; last year, over 60 billion aluminum beverage containers were sold in the United States.

The recycling of aluminum has grown in popularity proportionally to the increased use of the metal. The energy savings resulting from the use of recycled aluminum as compared with total energy expended in refining new materials ranges from 92 to 97%. The energy savings together with the new mandatory deposit laws passed in nine states (to date) have resulted in over one half of the aluminum beverage containers sold in the U.S. being recycled: 30 billion cans (more than 1 billioi pounds) in 1985.

Figure 6-6 illustrates the flow of aluminum scrap in processing and Tab e 6-8 gives the energy requirements for the recycling of cans. The procedure usually involves beverage or can companies buying or collecti ng used beverage cans from independent suppliers or brokers or their own network of collection centers, and then passing the cans to a primary aluminum producer for conversion into new can sheet. Primary producers incl ude compani es such as Kai ser , Howmet , A1 coa , and Reynolds. Companies operating only brokerage and tolling systems include Continental Resource Recovery and Ball Corp.

6-28 contarmnatea Iron Bearing ST Sc(ap

Oectricityd & Screening Burning, Fwl --* Drying, 1 Sweating &tack Leaching 1 Air- Rotary A Furnace Oecbicity- -Stack c ’, T

lack Induction Air Smening EIecbicityL Furnace F% Furnace - 1250-1400F 1250-1400 F 4ron *& 1 u2’ N2 Electricity- solvent- Fluxing, Handling Hot R~~~~ Degassing, & -Air On-Site Generator Demagging Coding HectlkityL Air- pace Cond

ux. Equipment

Figure 6-6. Secondary Non-Ferrous Metals (A1 uminum) Process Flow Diagram

Source: Ref. 10

6-29 OOOIC) on0 onm no z: I 991 9993 223 399 .... 9999 ... L.. .. Y?Y 00- 00" -?-VI 0-01 nonc UlNC en uc I on-0 0-0**m -n 'Oh un I *NNQ 0100 enN4 .?-ha m4-4 ?n 2- I -4N n *N -4N WI I I 3 n- I 00 000 00 00 000 000 00 00 00 300 j 00 nn 000CdN nn00 o*.YO OnN?-Oh UO"Om- 00e- -30, n mn DOO I m* z: I *- 30 ON 35- I ON 2- I ...... , ...... d .. OS 00- 10 00 0 3' 00" 'J 0 =Id 30 +.*Q , Y? I -1

I I n- I ...... n 51 000 01 nom I VI0 xu I 000 00 000 00 no 0J 30 I =,n elW- I c- 000 ennn n 00 -002 QQO 00 NO"-30 -NC 00-4 D 0- ** JU----I *J'd mN NIO - -4-4 i. I I I I

v)-I I v) "l J"lVI "lr 3 -4s uu22 0 2 I 2 -8 3 LI) 'LY LY WYdm -Y -uune1 gz n II n.- 2n I-W.J~ c On en Um 2: 2 axan 2xan '0 can JI 3 -a* 033Jcm -+VI a %I-I1 52:; Lao 0-0XYId 3eca 3 eo 1122-33 Ud-¶I3 Ye3X*-I 2%: v1sm-l Si-I x3n2 Zl*2 rzd

?? 933 ??3 ???Y 9": 300... 33Y Y3': oqno... 394 no0... OCOO oocn n OC 000 omn OONFDN 300 *ON COhJ o o -3m Jn " *I- PmJ mJ* 000' h 4 " -.a N" 7

030 0 00 0 mN00 00 oc 00 0330003 00 3" 001CON onN -I'*-I CO33 ou-0 ON** 90"U 9 .. 0, ?3 "9"...... Q*^...... 0 0- 0 00 00- 3- 00 0- 000 3.3 -.VI...... nu) Cu) ccY)VI CY)-0 OOVI 3VI Om on 033 cc 30 cc Om-00 3c Joc *"C OQN 3-J m ' 34 - ... d.4JJY)

nu 2 U nu -2 3.u J3-xu Bu nu 0- a-ad 4- 3- 22 - 3- - QQ I ocuu I2%I- 2-xu adu u "W --I %: nc ne D ucnr uc VI 5: au VI JU nd ccou 02 Ud ou cu 2 J2-8Y c) IIXU -cw UUUJW c r w JJW cuw3-2 JUY n .% iu %W 3w-3 3-2-x-u TnW 303-8 a2VIU nauJ-3 222axw "-32 302 2-3Tau. ,4-24 .Y mQuAl XZQL I a 3" sad rrxu

3 mC 3 0 0 3 0 0 0 0 n mVI Q n 0 m 0 "7" * f J4 4* ?...... 4

0 Y 0 LU J z n u - I 0Y n -8 z a a Y JL Uiu L 3 W z *3 3 u0 U n w0 c VIu z U3 4Y U u L u 0 0 Y 0 0 u J 2 73 0 rI& I - > - - z a - - I J J - uI c c "l T a wJ 3 x 7 0 rr c 3-8 --I v1 23 3 u4 J1 30 dY r uU U0 L.l z

... Y -l * "7 0 c D 0. 0..

6 -30 REF ERE NC ES

1. "Sol id Waste Data .'I McLean, VA: JRB Associates, 1981.

2. R.M. Hall. "Liquid Nitrogen in the Reclamation Industry." In Proceedings of the Seventh International Cryogenic Engineering Conference, vol . 7, July 1978. 3. "Cryogenic Grinding Gets a Lift from New Stress on Cost Reduction." Modern P1 astics, December 1977.

4. J.H. Bilbrey, Jr. "Use of Cryogenics in Scrap Processing." In Proceedings of the Fourth Mineral Waste Utilization Symposium, 1974.

5. "Sweden's Scrap Reclaim Process .I' European Rubber Journal, September 1980.

6. S.L. Rice, S.F. Wayne and N.P. Shapiro. "Cryogenic Process Remova of Insulation from Electrical Wire." ASME Paper 75WA/PID, 1975.

7. Norman R. Braton and James A. Kontsky. "Cryogenic Recycling of Materials from the Automobile." Scrap Age, April 1977.

8. P. Pearce. "Cryogenic Scrap Fragmentation." I Mech E, October 1976.

9. E. Radha Krishnan. "Recovery of Heavy Metals from Steel Making Dust.'' Environmental Progress, vol. 2, no. 3, August 19, 1983.

10. H.L. Brown, B.B. Hamel, B.A. Hedman. Energy Analysis of 108 Industrial Processes. SePtember 1985.

6-31

Section 7

DRINKING WATER

BACKGROUND

There are approximately 60,000 pub1 ic water treatment uti1ities providing drinking water for domestic, non-residential , and industrial use in the United States. These plants treat approximately 32 billion gallons of water per day, the equivalent of 133 gallons of drinking water per person per day. Water treatment plants, like many manufacturing facilities are very energy-intensive and pumping accounts for the largest portion of the energy used in the plant.

The overwhelming majority of the water utilities are extremely small, typically serving fewer than 2,500 people. But while more than 80% of the country's water systems fit this category, they serve only about 8% of the public. At the other end of the scale in terms of size are 1% the of water treatment utilities, serving at least 50,000 people each, who together handle some 63% of the population.

Water treatment plants draw on surface water, groundwater, or both as their raw water source. Over 88% of water treatment facilities use groundwater as a primary source (more than 50% of their raw water supply); the remaining 12% use surface water as their primary supply.

The main function of a water utility is to deliver to the consumer water of an acceptable quality. The Environmental Protection Agency (EPA) sets standards that must be adhered to before water can be made available for human consumption. Furthermore, under provisions of the Safe Drinking Water Act, Revised National Primary Drinking Water Regulations must be developed for any drinking water substance that may have any adverse affect on health. The revised regulations will span a1 1 classes of drinking water contaminants including biological contaminants, organic and inorganic chemicals and radionuclides. As a consequence, EPA is currently engaged in the most detailed and comprehensive assessment of drinking water quality specifications ever attempted.

7-1 The treatment processes currently utilized by water systems to achieve the quality standards required by EPA depends on their source of raw water and may include a combination of presedimentation, coagulation, flocculation, sedimentation, softening, or disinfection. Water disinfection, however, is of particular importance because of the need to produce a biologically safe product. In addition, water disinfection is the major source of synthetic organic chemicals in public drinking water supplies.

There are four common disinfectants in use today: chlorine, ozone, chlorine dioxide and chloramines. Table 7-1 shows the number of water utilities using various disinfection methods in the U.S. The data presented is based on a recently completed survey of the 600 largest utilities in the United States and was conducted by the American Water Works Association.

The four most common disinfectants will be discussed in the following sections

Table 7-1

WATER DISINFECTION (Data Based on 430 of the 600 Largest Utilities that Responded to the Survey)

Disinfectant Surface Water-- Groundwater Chl orine (C12) 220 184

Chlorine Dioride (C102) 32 4

Chl orami ne 75 39

Ozone 2 0

Source: Ref. 1

Chlorine-

Chlorine has been used to treat drinking water supplies for more than 75 years, and is the most widely used method in the United States. Its advantages include convenience; well-establ ished, satisfactory performance; and the ability to maintain an easily-measured residual, thereby providing protection against possible

7-2 contamination in the distribution system. There are disadvantages to the use of chlorination, including by-products, safety risks involved in transporting the liquid chlorine to the site, and hazards involved with handling and storing the chemical. Though chlorine by-products are deemed to be a health risk, the health effects have not yet been determined, with the exception of Trihalomethanes (THM) chloroform which has been linked to cancer in both laboratory and epidemiological studies.

Chlorine is the most cost-effective disinfectant of the four studied here (see Table 7-2). The total treatment costs for a 100 MGD plant with existing chlorination faci 1 ities would be approximately 0.004/1000 gal (1980 dol 1 ars) .

Ozone

Ozone is used in more than 1,100 water treatment plants worldwide for one or more of the following procedures:

e Iron and manganese removal

e Oxidation of organics, including color bodies, taste and odor bodies, algae, suspended solids and dissolved solids

0 Microflocculation

0 Bacterial disinfection e Viral inactivation

Table 7-3 lists water treatment plants in the United States with ozonation systems in operation, under construction, or planned as of September 1984. The worlds largest drinking water treatment plant using ozonation is currently in operation in Los Ange es. The flow rate for this plant is approximately 600 mgd.

Ozone is an unstable gas that boils at -112°C at atmospheric pressure; is partially soluble in water; and has a characteristic, penetrating odor that is easily detectab e at low concentrations (0.01 to 0.05 ppm). For water treatment processes, ozone is generated on-site by an electrical discharge in an air or oxygen stream. Dosages are approximately 1 to 2 mg per liter of water. The electricity requirements for ozone generators are between 13 and 22 kWh/kg of ozone depending on the production rate. Thus a large ozone plant on the order of 600 MGD consumes approximately 30 mi11 ion kWh annually.

7-3 Table 7-2 DISINFECTANTS Chlorine Ozone Chlorine Dioxide Chloramines

Off-site On-site from 0 or air 2 On-sitefrom C12lNaCIO 20' On-site from CI 2 and NH3 NaOCVNaC102

OxIdation potential! Third to ozone; good bacteriocide; Highest; short contact periods; Second to zone; good bactericide Fourth to ozone; poor biocide; oisNnfecmn efficiency decreases with incr. pH good bactericide, virucide and and virucide; efficiency increases requires long contact action; (less HOCI) cysticide; no little pH effect with incr. pH reduced by low temperature and high pH

Odor'coloritaste Can cause odorsflastes; no color Removes tastelodorslcolor, iron Removes taselodors Reduces or eliminates musty, removal effect: no odorhaste removal and manganese, algae, organics, moldy tastes, odors, especially cyanides, sulfides, turbidity phenol compounds.

Measurement of Residual Eight methods; HOC1 and OCI- not Tiltration DPD and FACTS, Tolometry, mod.OT Amperiometric titration, DPD easily distinguished Amperiometric titration; C102 and Clq- can be distinguished; slowly changes to ClOi and Clg-

Persistence of Residual Persists Does not persist Persists Persists; more stable than chlorine

Oxidation reaction THM's including CHCS ; possibly No THMs; products not knows, No THMs if no free chlorine present; No THMs if no free chlorine proodcts other chlorinated by-products (e.9.. but are thought to be nonhalo- chlorate and chloriie present; monochloramine and N-chloramines. trichloroacetone, genated and more biodegrad- dichloramine chlorophenols) able than before oxidation

Effects on heahh from CHCS is carcinogenic; epidemiology Not known: no epidemiological Very little known; no epidemiological Non positive yet; monochlora- brsnking disinfected supports some adverse effect; CI studies studies; chlorite is a potent Mat Hb mine may be carcinogenic; water may form compounds of mncern former and may depress speramato- associated with production of within body: several by-products genesis; chlorine dioxide possesses Met Hb in dialysis patients under study may be carcinogenic activity as an antithyroid agent

Safety Gas is respiratory irritant; can cause Easily detected due to strong See chlorine See chlorine; NH3 can cause permanent damage or death; bodily odor at low mncentrations (.01 skin and eye irritation; fatal contact with liquid is hazardous ppm) can be fatal (100 ppm for at high concentrations (104 103 min. or 10, ppm for .5 min.) PPm)

Ccsts Size Plant lOMGD 100MGD 10 MGD lWMGD 10 MGD 1OOMGD IOmGD 100 MGD C'1000 Sal Total 0.57 0.40 2.2 1.2 2.9 2.1 1.02 0.68

hllscellaneious Not appropriate for high TOC Does not react with ammonia Not appropriate for waters high waters; reduces CI2 demand; pre- chlorine demand; results in ozonation removes THM precur- lower CI re uirements; may 2 .q sers: adds 02 to water; improved be appropriate for waters with coagulation with alum and settling high PH destabilization of certain colloids. cvanide destruction.

Source: Ref. 2

Ii I Table 7-3

U.S. POTABLE WATER TREATMENT PLANTS USING OZONE (September 1984)

In Operation

Whiting, IN T& 0 1940 4 15,000 Strasburg, PA disinf. 1973 0.1 Grandin, ND Fd & Mn 1978 0.05 1 Saratoga, WY T&Q 1978 3.5 13,200 Bay City, MI T&O 1978 40 162,480 Monroe, MI T&0 1979 18 73,119 Newport, DE disinf. 1979 0.25 1,016 Newport, RI THM precursors ; 1980 5 20,311 T&O; color No. Tarrytown, NY T& 0 1980 1.2 4,875 Kennewick, WA color; T&O 1980 3 12,187 Elizabeth City, NC col or 1981 5 20,311 Casper, WY disinf. 1982 0.145 20,311 Ephrata Borough, PA T&O 1982 5 549 New Ulm, MN Fe & Mn 1982 2.6 10,562 South Bay, FL color 1982 2.2 8,937 Roc kwood , TN* flocculation; 1982 6 22,712 THM precursors Potsdam, NY color 1984 1 3,786 Beria, OH* THM & T&0 1984 3.6 14,348 Belle Glade, FL* color, THM pre- 1984 6 22,812 cursors & algae Stillwater, OK color 1984 5 18,927 Lakeport, CA organ ics ** 1982 <2 <10,000 Mi 11s Wardel 1, WY disinf. & T&O 1983 4 15,142

1-5 Table 7-3 (continued)

Primary Purpose Startup Average Flow Rate Location of Ozone Date mgd M3/day

Under Construction

New York, NV organics 1984 3 (pilot) 11,348 Hac ken sack , NJ color, Fe & Mn; 1986 100 378 ,540 THM precursors Los Angeles, CA mic rof 1 ocul ati on 1986 5 80 2,195,531 and organics

-Under Design

Myrtle Beach, SC* color; THM 1987 30 121,865 precursors Clinton, IL Fe 1985 1.5 5,679

Pilot Plant Studies

Rocky Mount, NC color; THMS Celina, OH T&O; THM precursors

* 2-stage ozonation plants ** ozonation prior to GAC adsorption (- BAC process) Source: Ref. 3

7-6 A Powerful, non-selective oxidant, ozone is a highly effective bactericide; it is relatively unaffected by pH or temperature changes and requires only low concentrations and minimal contact periods, For instance, as a treatment standard for viral inactivation, the city of Paris, France adopted a criterion of 0.4 mg/l residual ozone four minutes after the initial ozone demand has been satisfied. This standard is commonly used in the industry.

By-products of drinking water ozonation have not yet been established, although it is known that THMs are not among them. It is known that ozonation products of organic materials are usually more readily biodegradable and less toxic than the original compound. Since ozone can be generated on-site safety risks are relatively low, so long as adequate air monitoring and venting equipment is available. Disadvantages of ozonation include high costs and a lack of persistance as a residual in the distribution system. The ozone has such high reactivity that a second disinfectant must generally be used to provide a stable residue.

In Europe, chlorine is more expensive than ozone, therefore ozonation is the most commonly used process there. In the United States, on the other hand, the costs of ozonation are the second highest of the four drinking water treatment a1 ternatives, (Table 7-4), primarily because ozonation is energy-intensive. However, the use of ozonation as an integral part of the water treatment scheme can reduce treatment costs for chlorination by reducing coagulant dosages and allowing increased filtration rates. The estimated total treatment costs of a 100 MGD plant ozonation system amount to $0.012/ 1000 gal (1980 dollars).

Chlorine Dioxide

Chorine dioxide (C102) is an effective bactericide and virucide under the pH, temperature, and turbidity of typical potable water treatment. It was first used for water treatment in the United States at Niagara Falls, New York in 1944.

Chlorine dioxide is usually generated on site, although "stabilized" chlorine dioxide is available. Useful for the control of tastes and odors, C102 provides a persistent residual in the distribution system and does not impart a chlorinous taste to the water. The by-products of using C102 as a water disinfectant are not fully known despite its rather widespread use in community drinking water treatment. However, research has shown that THMs are not produced if no free chlorine is present.

7-1 Table 7-4

COMPARISON OF COSTS FOR DISINFECTION BY CHLORINE, CHLORAMINES, OZONE, AND CHLORINE DIOXIDE

Chlorine P1 ant Size Chl orine Chl orami nes Oxone Dioxide

Total Costs

37.8 ML/d 10 mgd 0.57 1.02 2.2 2.9 378.5 ML/d 100 mgd 0.40 0.68 1.2 2.1

Cost Assumptions

Chemical costs C12 $/ton 300 300 NA 300 NH $/ton NA 2 00 NA NA Na?102 '$/ton Dosage mg/L 2 3+ 1 1 Contact time - min 20 20 10 20 Operating capacity - percent 70 70 70 70

- Source: Ref. 2

7-8 Chlorine dioxide is the most expensive of the four disinfectants compared here: for a 100 MGD plant, total costs are $0.021/1000 gal (Table 7-4).

Chloramines

Chloramines were widely used in the 1930's for disinfection, but their usage decreased with the introduction of chlorination. Chloramines provide a relatively weak disinfectant for bacteria, protozoa, and particularly viruses, Therefore, chloramines require long contact times and as a result are today primarily used for residual rather than primary disinfection.

Chloramines are formed when ammonia reacts with free available chlorine, thus minimizing any further formation of THMs. When chloramines are used to provide a residual, the chlorinous taste and odor of the water is also minimized.

The cost data in Table 7-4 shows that chloramine is second to chlorine in cost; for a 100 MGD plant, total costs are $0.64/1000 gal.

SUMMARY

Based on the information currently available, none of the four common disinfectants is ideal; each has advantages and disadvantages. Because of its low cost, as shown on Table 7-4, chlorine is the preferred disinfectant. However, due to the potentially harmful by-products of chlorine disinfection, an ozone system may be Preferrable. In order to be used extensively however, the cost of using ozonation systems must be reduced.

7-9 REFERENCES

1. American Water Works Associates, 1985.

2. Wolfe, Roy L. "Inorganic Chloramines as Drinking Water Disinfectants: A Review." Journal AWWA 76:5:75, May 1984.

3. Rice, G. Rip, "Ozone for Drinking Water Treatment - Evolution and Present .._ Status", Proceedings of Ozone for Waste Water Treatment, Oct., 1985.

7-10 Section 8

INST ITUTI ONAL ISSUES

HAZARDOUS WASTE LEGISLATION

Over a dozen laws have been passed by the federal government to regulate various hazardous material s (Tab1 e 8-1). In particular, the Resource Conservation and Recovery Act (RCRA) of 1976 and subsequent amendments added to the bill in 1978, 1980 and 1984 were enacted by Congress to address the growing national problem of waste generation and disposal. The original intent of RCRA was to promote the recycling and reuse of materials and to protect the environment from improper management of industrial hazardous wastes. Subtitle C of RCRA required EPA to (3):-

Promulgate regulations identifying the characteristics of hazardous waste and provide a listing of particular substances to be regulated as hazardous wastes under RCRA (Section 3001) ;

Establ ish a manifest system for l'cradl e-to-grave" tracking of hazardous waste shipments (Section 3002);

Establ ish standards governing the generation (Section 3002) and transportation (Section 3003) of hazardous wastes;

Promulgate regulations to ensure proper treatment , storage, and disposal of hazardous wastes, including the promulgation of standards governing the location, design, construction and operating rocedur- es of hazardous waste treatment, storage, and disposal (TSDP facilities (Section 3004) ;

Grant "interim status" (temporary permits) to a1 1 TSD facilities that were ''in existence" on November 19, 1980 and that (1) complied with the Notification requirements of Section 3010(a); and (2) submitted Part A Hazardous Waste Permit Applications to EPA by November 19, 1980 (Section 3005(e));

Issue final permits to new and existing TSD facilities as a mechanism for applying the facility standards developed under Section 3004 to individual facilities (Section 3005); and,

Promulgate guidelines to assist States in the development of state hazardous waste programs, and to grant interim and final authoriza- tion for qualified State programs to administer the RCRA Hazardous Waste Regulatory Program in lieu of the Federal program, including the issuance and enforcement of permits for the storage, treatment, and disposal of hazardous wastes.

8- 1 Table 8-1

SUMMARY OF KEY FEDERAL LAWS AND RESPONSIBLE AGENCIES RELATED TO THE CONTROL AND REGULATION OF HAZARDOUS AND TOXIC MATERIALS

Kesponsibic Regulatory Objectives Key Federal Laws Agencies

Air pollutioii control Clzan Air Act

Water pollurion control EPA tt’A EI’A. C‘orp4 of En gin em

Regulation of hazardous waste Ke?;ource Conservation and Recowry Act EPA. DOT Comprehensive En\.ironmcntal Response. Compensation and Liability Act EPA Ham rd o u s Mat e ri a1 s Transport at ion Act DOT. EPA

Regulation of the transportation of J-iazardous Materials Transportation hazardous materials Act DOT Dangerous Cargo Act DOT Federal Railroad Safety Act DOT Ports and Waterways Safety Act DOT

Regulation of the workplace Occupational Safety and Health Act OSHA. NIOSH Federal Mine Safety and Health Act \lSIi,4. NIOSH

Regulation of toxic industrial chemicals Toxic Substances Control Act EPA

Regulation of pesticides Federal Insecticide, Fungicide and Rodenticide Act EPA Federal Environmental Pesticide Control Act EPA

Note: EPA-U.S. Environmental Protection Agency DOT-U.S. Department of Transportation OSIlA--Occupational Safety and Health Administration NIOSH-National Institute of Occupational Safety and Health MSHA--Mine Safety and Health Administration

Source: Ref. 6, p. 51

8- 2 EPA has developed four criteria to be used to identify the characteristics of hazardous materials (4):-

0 Ignitability - posing a fire hazard during routine management;

0 Corrosivity - ability to corrode standard containers or to dissolve toxic components of other wastes;

0 Reactivity - tendency to explode under normal management conditions , to react violently when mixed with water, or to generate toxic gases;

0 EP toxicity (as determined by a specific extraction procedure) - presence of certain toxic materials (as listed in 40 CFR 261.24) at levels greater than those specified in the regulation.

Wastes which exhibit any of these criteria or are listed as hazardous by EPA are subject to regulation. However, some wastes are exempt from regulation, (Table 8- Z), such as those from burning fossil fuels; from oil, gas, and geothermal energy exploration; and cement-kiln dust. Another notable exception is waste produced from burning incinerable solid waste for the purpose of energy recovery.

States are encouraged under RCRA to assume primacy for regulating hazardous waste management. Incentive is offered in the form of both federal grants and technical assistance for development and operation of state programs.

Subtitle ' I of the Solid Waste Amendments of 1984 to RCRA provides for a COm- prehensive regulatory program for underground tanks that store petroleum and hazardous materials, as defined by the Comprehensive Environmental Response Compensation and Liability Act (CERCLA). There are over 2 million, some estimate as high as 5 million, of these tanks in the U.S. today and thousands are leaking (2). A summary of the schedules for the Leaking Underground Storage Tank (LUST) program is listed in Table 8-3.

The 1984 RCRA Amendments also added small-quantity generators to those who who produce between 100 and 1000 kg per month of wastes, and has a statutory deadline of September 1986. Among those affected are laundromats, hospitals, and machine shops. Table 8-4 lists other additions to RCRA made in 1984 and the dates at which they are set to come into effect.

Gene Lucero, the director of the Office of Waste Programs Enforcement at EPA, recently spoke on the history and future of the hazardous waste programs at the agency. He confirmed that when the 1984 Amendments to RCRA were enacted, there was

8-3 Table 8-2

EXAMPLES OF EXEMPTIONS FROM FEDERAL REGULATION AS HAZARDOUS WASTE

Estimated annual generation Waste type (million metric tons) Possible hazard Determined by

Fly and bottom ash from burning fossile fuels '. .. 66 Trace toxic metals RCRA Fuels gas emission control waste ...... Unknown Toxic organics, and inorganics RCRA Mining waste, including radioactive waste 5.""...... 2,100 Toxic metals; acidity; radioactivity RCRA Domestic sewage disch rged into publicly owned treatment works i...... 5 Uncertain, toxic metals likely RCRA Cement kiln dusta...... 12 Alkalinity, toxic metals RCRA Gas and oil drilling muds and production waste; Alkalinity, toxic metals, toxic geothermal energy waste ...... Unknown organics, salinity RCRA NPDES permitted industrial discharge ...... Unknown Toxic organics, heavy metals RCRA Irrigation return flows ...... Unknown Pesticides, fertilizers RCRA Waste burned as fuelso...... 19 Unburned toxic organics E PA Waste oil...... Unknown Toxic organics, toxic metals EPA Infectious waste ...... Unknown Infectious materials EPA cn Small volume generators4 2.7 - 4.0 Possibly any hazardous waste EPA P Agricultural waste ...... Unknown Variable t E PA Wastes exempted under delisting petitions ...... Unknown Presumably insignificant E PA Deferred regulations ...... Unknown Unknown E PA EPA deregulation ...... Unknown Presumably insignificant EPA Toxicity test exemptions 3...... Unknown Organics E PA Recycled waste $...... Unknown Improper application of various EPA materials t Wastes may be delisted on the basis of a petition that is concerned only with the constituent(s) which have determined the original listing; hoM other hazardous constituents may be present which have previously been unrecognized administratively. * Wastes not identified as toxic by the EPA extraction procedure test and not otherwise listed by EPA. * Legitimate recycling is exempt from RCRA regulations except for storage. However, there have been numerous incidents (e.g., the dioxin cas Missouri) involving recycled materials which are still hazardous.

SOURCES: a Federal Reqister, vol. 43, No. 243, 12/18/78. "Technical Environmental Impact of Various Approaches for Regulating Small Volume Hazardous Waste Generators" (Washington, D.C.: Environmental Protection Agency, contract No. 68-02-2613, TRW, December 1979). C"A Technical Overview of the Concept of Disposing of Hazardous Wastes in Industrial Boilers" (Cincinnati, Ohio: Environmental Protection Agency, contract No. 68-03-2567, Acurex Corp., October 1981). d"The RCRA Exemption for Small Volume Hazardous Waste Generators, Staff Memorandum" (Washington, D.C.: U.S. Congress, Office of Technology Assessment, July 1982.

iI I Table 8-3

SUMMARY OF EPA REGULATION AND GUIDELINE SCHEDULE: LUST PROGRAM

Interim Regulations May 1985

Governors designate State Agency May 1985 States prescribe Form of Notice November 1985

Depositors requ red to notify tank December 1985 owners of notif cation requirements

Owners required to notify state or May 1986 local agency of existence of tanks (age, size, etc 1 Owners required to notify state or May 1986 local agency of tanks taken out of service after June 1, 1974

USEPA to promulgate regulations May 1987 for all underground storage tanks

Financial and liability regulations May 1987 promulgated by USEPA

New tank performance standards November 1987

Financi a1 responsi bi1 ity regul ations May 1988 become Effective

Source: Ref. 2, p.27

8- 5 a general feeling among regulators that a stricter approach that included deterrent enforcement would be needed if any real progress toward improved hazardous waste management was to be made. Therefore, the new Corrective Action Program initiated by €PA has lead to widespread environmental auditing of companies to determine the liabilities and risks of RCRA upon them. Lucero predicts that a disposal crisis will occur in 1990 as a direct result of the new legislation, both in capacity and in ability to land dispose wastes (L).

Congress passed CERCLA, otherwise known as Superfund, in 1980 in an effort to deal with the toxic waste sites that require cleanup. There are now about 23,000 sites believed to need attention, though only 2,000 of these are on the National Priority List (NPL) .

Congress Set aside $1.6 billion to fund the initial 5-year program and cleared a $150 million loan on March 21, 1986 to keep the program funded until an agreement for another five-year cleanup program can be reached (L). Lucero believes that when Superfund is reauthorized most of the money will go to those cleaning up the sites, but some part may go toward creating a Federal insurance agency for hazardous wastes.

NON-HAZARDOUS WASTE REGULATIONS

As provided for in RCRA, the EPA has promulgated the Criteria for Classification of Solid Waste Disposal Facilities and Practices (40 CFR Part 257). Facilities which fail to satisfy the Criteria will be considered illegal and required to upgrade. These Criteria are primarily oriented toward the disposal of munici pal sol id waste. The Criteria include: groundwater protection, surface water management, si te 1 ocations , control 1 ed access, etc.

EPA has also proposed Guidelines for the Landfill Disposal of Solid Waste (Federal Register, March 26, 1979). These Guide1 ines represent EPA's recommendations for the location, design, construction, operation, maintenance, closure, and post-cl osure of solid waste landfill disposal facilities. EPA suggests that in many cases compliance with the aforementioned Criteria can be achieved by applying practices outlined in the Guidelines. As with the Criteria, these Guidelines are oriented toward the disposal of municipal solid waste. However, the Guidelines are more detailed than the Criteria.

8-6 Table 8-4

NEW EPA ACTIVITIES MANDATED BY 1984 RCRA AMENDMENTS

Stat u tory Activity Dead1 ine

Expand Regulated Waste Coverage Sinal 1 quantity generator study 2/85 Small quantity generator regulations 3/86 New 1 istings of hazardous substances 4/85 New toxicity testing procedures 2/87 New characteristics of hazardous wastes based on organic toxicity 10186

Change Waste Management Practices Ban on land disposal of bulk liquids in landfills 4/85 Ban on land disposal of high priority hazardous wastes 6/87 Ban on land disposal of solvents and dioxins 10186 Minimum technological requirements for land disposal facilities 10184 Potential bans for first one-third of EPA's listed wastes 7/88 Potenti a1 bans for second one-thi rd of EPA' s 1 isted wastes 5/89 Potenti a1 bans for third one-thi rd of EPAls 1 isted wastes 419 1 Ban on injecting wastes above or into drinking water aquifer 4/85 Standards for acceptable treatment technologies to diminish Concurrent with toxicity or risk of exposure Prohibitions

Reg ulate Add it ional Act iv iti es Interim construction standards for underground storage tanks 2/85 Performance regulations for existing and new underground 4/87 storage tanks Salt dome storage performance standards No limit Regul ations to minimi ze 1 and di sposal of hazardous 1 iquids 2/86 Regulations for deep well injection of high priority wastes, 7/88 dioxins, and solvents Standards for monitoring and control of air emissions from 4/87 treatment, storage, or disposal (TSD) facil iti es Standards for leak detection systems for land facilities 4/87 Standards for areas of vulnerable hydrology precluding siting 4186 of TSD facilities Regulations on blending and burning hazardous wastes 10186

8-7 Tab1 e 8-4 (continued)

Stat ut o ry Activity Dead1 ine

Regulate Additional Activities (Continued) Regulations on recordkeeping for blending and burning 1/86 Regulations on transporting fuels with hazardous wastes 10186 Final permits for all TSD facilities io/aa Final incinerator permits 10/90 Standards on generation and transportation of used oil for recycle 10186 Regulations on exporting hazardous wastes from the United States 10185 Ruling on the hazardousness of discharge from pub1 icly owned 4/86 sewage treatment works

-- Source: Congressional Budget Office, based on the 1984 RCRA amendments. a. Does not include several studies and inventories that the EPA must also perform within 36 months of enactment and several notification and certification activities required of private industry.

8-8 On September 23, 1981 the EPA modified the Groundwater, Surface Water, and Air sections of the Criteria for the classification of Solid Waste Disposal Facilities and Practices (non-hazardous waste regulations) in 40 CFR Part 257. Most of the changes were administrative in nature and did not affect design considerations.

For instance, the existing regulations concerning groundwater establish sol id waste boundaries and alternative boundaries beyond which a solid waste disposal facility may not contaminate groundwater. In the original act, only a state with an approved sol id waste managment plan could establish an a1 ternate boundary, but the amendment to this rule eliminates this requirement. A mechanism was instituted whereby a party could directly petition the courts to establish an alternate boundary. On the other hand, the amendments to the surface water and air criteria only clarify which portion of RCRA is to be implemented in that particular set of criteria.

8-9 REFERENCES

1. "Congress Approves $150 mil1 ion loan to fund Superfund Through May 31." Toxic Materials News, March 26, 1986, p. 101

2. Paul V. Knopp. "Underground Tank Management .'I Pol 1 ution Engineering-, September 1985, pp. 24-27.

3. US EPA office of Solid Waste and Emergency Response. National Survey of Hazardous Waste Generators and Treatment , Storage 8 Disposal Facilities Regulated Under RCRA in 1981. Washington, D.C.: Government Printing Office, 1984.

4. U.S. Congress. Office of Technology Assessment. Technologies and Management Strategies for Hazardous Waste Control. Washington, D.C.: Government Printing Office, 1983.

5. Gene Lucero, Director of the office of Waste Proyrams Enforcement, USEPA, Keynote Speaker at Hazardous Materials Management Conference (HAZMALON) , Apri 1 29, 1986

6. George Camougis, "Toxic Materials Risk Assessment: A Practical Guide," Pollution Engineering. August, 1985.

8-10 Section 9

CURRENT WASTE TECHNOLOGIES RESEARCH

EPRI WASTE-RELATED RESEARCH

Research involved with the management of liquid and solid waste has been of growing importance to electric utilities in recent years as they have been faced with stricter emission and disposal regulations and potential liability for past and future waste practices. Research at EPRI has reflected these needs with the performance of studies on methods to recycle, recover, monitor, treat, and dispose of wastes. Emphasis has been given to management techniques which are both economical ly reasonable and satisfy the requirements of the 1 aw.

Table 9-1 contains the planned expenditures for liquid and solid waste management research at EPRI for the 1985-89 time period (l-). Although these numbers have been modified by recent changes in the EPRI budget, they are still approximately correct.

Table 9-1

PLANNED EPRI EXPENDITURES FOR WASTE RESEARCH (1985 - 1989) (Mill ion dol 1 ars)

Hazardous1Toxic Substances 14.2 HazardousITox ic Waste Manangement 16.3 Solid Waste Studies 26.3 Sol ids Disposal Rc Reuse 10.3 Water Quali ty Control 8.9

The major divisions involved in non-nuclear liquid and solid waste research at EPRI have been the Energy Analysis and Environment Division and the Coal Combustion Systems Division. The bulk of the waste-related research within the Coal Combustion Systems Division has been carried out under the Heat, Waste, and Water Management Program. The technical approach taken by the Program for Waste Manangement Practices has been to develop enhanced environmental control equipment and integrated processes to improve the performance of emission control systems. Within the

9- 1 program plans are to spend $12.5 million in the Water Quality Control Subprogram and $15.0 million for the Solid By-products Subprogram. The following list shows the goals of these subprograms for the 1985-89 time period:

Water Quali ty Control

0 Develop comprehensive guide1 ines for integrated water and wastewater man ag eme n t .

0 Demonstrate improved biofoul ing methods.

0 Develop aqueous discharge monitoring and treatment methods.

Sol id By-products Management

0 Develop and demonstrate resource recovery and by-product uti1 izati on options.

0 Develop and demonstrate PCB disposal and clean-up methods.

0 Develop and demonstrate treatment, management and disposal techniques techniques for toxic and low volume wastes.

0 Demonstrate site selection, preparation, and monitoring methods and economical disposal procedures for ash and FGD sludge.

A specific listing of related EPRI R&D projects can be found in Table 9-2. Subjects covered regarding water quality include trace element removal from discharge water (RP910), reduced chlorine dosages for biofoul ing control (RP2300), and Control systems for waste streams (RP1609). In the solid waste area studies cover coal combustion by-product uti1ization, such as metal recovery (RP1404) and incorporating ash into roadways (RP2422); sludge and solid waste disposal (RP1728 and RP1405); and the effectiveness of liners at solid waste disposal facilities (RP1457).

In addition to studies on techniques for waste disposal and clean-up such as those concerning electrical capacitors containing PCBs, EPRI has conducted research into legislation affecting waste management. For example, the 1978 report entitled "The Impact of RCRA on Utility Solid Wastes" was followed by a more recent report on the same topic in 1982 (RP1728).

Waste Management

The technical approach to waste management carried out by the Energy Analysis and Environment (EA&E) Division is to describe the pathways of utility-related substances in the environment. Environmental Physics and Chemistry is the major

9-2 Table 9-2

EPRI R&D PROJECTS

Coal Combustion Systems- Division

Heat, Waste, and Water Management Program - RP733 - Condenser Biofoul ing Control : Chlorine Minimization, Ozonation, and Dechlorination

- RP910 - Trace Element Removal by Adsoprtion on Iorn Hydroxides - RP1260 - Advanced Heat, Waste, and Water Management Concepts - RP1263 - Disposal of Polychlorinated Biphenyl s (PCB) and PCB-Contaminated Materi a1 s - RP1404 - Fly Ash Metal Recovery - RP1405 - Sludge Disposal Demonstration from 20 MW Dua Alkali Scrubber - RP1457 - Leachate Control and Monitoring Systems for Solid Waste Disposal Facilities

- RP1609 - Integrated Environmental Control (IEC) Designs for Coal -Fi red Power Plants - RP1685 - By-product Disposal Manuals - RP1728 -Engineering Evaluation of Projected Sol id Waste Disposal Practices for Utilities

- RP1850 - Coal Combustion By-product Uti1i zation Guide1 ines - RP2114 - Water Management at Zero Discharge Power Plants - RP2215 - Low-Volume Solid Waste Management - RP2300 - Chlorination for Biofouling Control - RP2301 - Groundwater Users Databook - RP2422 - Ash Utilization in Roadways, Embankments, and Backfills

9-3 Table 9-2 (continued)

Energy Analysis and Environment Division

Environmental Physics and Chemistry Program - RP1057 - Organics in Fly Ash Analytical Techniques - RP1061 - Trace Elements and Their Chemical Form in a Modern Ash Disposal System

- RP1371 - Chemical Affiliation of Trace Metals in Ash - RP1486 - Chemical Characteristics of Sol id Waste from Conventional and Conversion P1 ants - RP1487 - Testing of Federal Solid Waste Criteria - RP1620 -Variations in the Chemical Composition of Ash - A Statistical Evaluation - RP1625 - Morphology and Chemical Specification of Fly Ash Particles - KP2198 - Solid Wastes Leaching and Attenuation Studies - RP2280 - Groundwater Transport Studies - RP2283 - Groundwater Sampl ing Procedures - RP2360 -Polychlorinated Dibenzofurans and Dibenzodioxins in Utility Insulating Oils

- RP2485 - Solid Waste Environmental Studies (SWES)

Source: EPRI

9-4 program conducting this type of research and has a planned expenditure of $7.2 million for 1985-86. Its three subprograms and the goals of each are presented below (refer to Table 9-2 for a specific listing of research by report number):

Air Quality

0 Assess utility contribution to regional air quality,

9 Predict local air quality as a function of power plant emissions.

0 Characteri ze pol 1 utants from various sources.

Land and Water Quality

0 Develop methods for measuring the movement of wastes in terrestrial and aquatic environments.

0 Predict utility contribution to groundwater quality.

Ex per iment a1 Met hods

0 Improve envi romental measurement techniques.

0 Develop new data hand1 ing approaches.

Waste-related work has also been carried out within EA&E through such other programs as the Ecological Studies Program and the Health Studies Program. The projects conducted by these programs have not been discussed because the subject matter concerns the effects and dispersion of wastes, while the contents of this report center around techno1 ogy and management issues. Within the Industrial Program of the Energy Management and Utilization Division are a number of waste-related projects. The only project dealing directly with waste is the Arc-Furnace Dust project funded by the center for Metals Production. This project is developing better methods to recycle electric arc furnace (EAF) dust which is now classified as a hazardous waste. Other projects which indirectly address waste are the freeze Concentration of cheese whey and the plasma-fired cupola. Table 9-3 shows a breakdown by waste type of research projects done at EPRI. As can be seen from the table a wide range of waste research is already being done by the various EPRI funded projects.

AMERICAN CHEMICAL SOCIETY

The American Chemical Society (ACS) is made up of chemical engineers and chemists dedicated to advancing science and educating the pub1 ic on chemistry-related issues. As part of the society's public education policy, a series of pamphlets

9-5 Table 9-3

PROJECT NUMBERS OF EPRI WASTE-RELATED RESEARCH

I I

2114 !416 2416 2416 1728 2215 1728 1609 1406 1 2215 !783 2783 221 5 221 5 I 1341.1 685 1487 1487 1401.2a2

1685.1404 1620 '1685.14Cd 631 786,1341 1625 1m1 p, 483 1405,786 1341,1685 1685.1404 5 14Cd 786 1486 1312.1 132.1 261.2303 1260 1260 2215 21M.902 1851 2215 1372.879.733.910 1851 2114 2330 1851 1457.1406 2485 1457,1406 2283 2485.2280 2198 I I 358 !570 2337 462,723,2434,2333,2375 06.901.1262.2159 1155.1310 1131.905.210.2486.2370 lM6 ~303.2333.2C2221B3.16X) 11308.1311 1795,2C23,22€d,1744,1776 1371 ,'t376.1616 1369,1003 1434.1616.1617.1 154.856.861 1222.1306.13X 937.1 31 5 2U1.781.414 60.862.9S5.1060 12%5 586.1622 j -2215 2215 2215 , 12215 1263 1263 1263 1263 1 X3 236: lZ3 -1263 1263 j i~3 1 I /:x7 i

2296 1557 828 1333 133 2691.2759 821 2414 724 I NVCLEAR WASTE I i 1274 1C25.1571

!I I I 1, I concerning waste regulatory issues has been published. They were written by the staff of the Office of Federal Regulatory Programs of the Society's Department of Public Affairs and have the following titles:

Hazardous Waste Management (1984) Chemical Risk: A Primer RCRA and Laboratories (19841(1983 Ground Water (1983) Acid Rain (1982)

One objective of the ACS is to promote alternatives to landfilling for the disposal of laboratory chemical wastes. This topic is addressed in a bulletin entitled "Less Is Better" which was written by the Subcommittee in Alternative Waste Management to the ACS Task Force on RCRA. The report discusses various reduction techniques, recycl ing surplus chemicals through exchanges, and the economics of purchasing chemicals in large quantities versus disposal costs.

ENVIRONMENTAL PROTECT ION AGENCY

The EPA Office of Research and Development conducts and coordinates research on the disposal and treatment of hazardous wastes. These programs gather information on the costs, effectiveness, and efficiency of existing and emerging, but not commercial, technologies for the disposal and treatment of hazardous wastes. Biological , chemical, physical , and thermal destruction processes are being researched.

EPA funding available for research done out of house for 1986 and funding predictions for 1987 are outlined in Table 9-4.

Two major research programs are being conducted by the A1 ternative Technology Division of the EPA: The Hazardous Waste Treatment Program, and the Thermal Destruction Research Program.

Hazardous Waste Treatment Program

The Hazardous Waste Treatment Program conducts research to meet several objectives. These objectives include the following:

0 To provide performance evaluations of a1 ternative hazardous waste treatment systems for the Office of Solid Wastes;

0 To identify industry change in processes and technologies for waste management which mprove performance;

0 To provide techno ogy for cleanup of Superfund sites;

9 -7 Table 9-4 EPA EXTRAMURAL HAZARDOUS WASTE RESEARCH BUDGET (MILLIONS OF 1986$)

Funding 1986 1987* Alternative Technologies 4.6 4.6

Waste Characterization 7.5 8.7 Risk Assessment Health Research

Dioxine Contaminated Wastes 2.2 1.9 Mobile Incinerator

Waste Identification 7.4 8.5

Land Disposal 5.9 4.3 Landfills Liners Air emissions

Incineration 1.9 1.5

Quality Assurance 1.3 1.3

Hazardous Releases 3.7 4.0 Oil spills Leaking Underground Storage Tanks Hazardous Waste Center at Tufts University 2.4 0.0

TOTAL 36.9 34.9

* Does not include Congressional actions pending which should raise total 1987 budget by a few million dollars.

9-8 To collect and distribute technical documents in an effort to encourage the adoption of technologies that are environmentally preferabl e; and

o To encourage the proposing and demonstration of alternative hazardous waste treatment technol ogies.

The Program for Existing Technologies plans to conduct pilot-scale or field tests to obtain data on various waste types targeted for priority use, including dioxin wastes , sol vents , cyanides , metal s , and ha1 ogenated organics. The technol ogies examined wi11 incl ude component separation , phase separation , neutral ization , chemical oxidation, incineration, and biological treatment.

The technical approach toward the research being conducted for Emerging Techno1 ogies wi 11 focus on di1 Ute aqueous wastes , sludge-suspended heavy metal s , soils contaminated by hazardous materials, sediments in harbors and waterways, and leachate from landfills. This program concentrates on chemical and biological detoxification methods. The biological detoxification segment of the program is concerned with examining the development of organisms, or substances produced by organisms, that can destroy specific pollutants or compounds. Research on chemical detoxification centers around development of chemical reagents, specifically, using polyethylene glycol and metals or metal hydroxides to solve the contaminated soil problem.

Technologies a1 so in progress for treating aqueous wastes include:

0 Low-pressure composite membranes able to separate organic and metal salts at high water fluxes;

e Low-cost lignin with the ability to be used as an adsorbent, as a weak cation exchange resin, and as a coagulant or precipitating agent;

e Solvent extraction system for PCB recovery from sediments;

e Supercri tical fluid extraction of aqueous hazardous wastes using carbon dioxide or lower hydrocarbons as the solvent for organic compo u nds ;

e Crosslinked polymer gels for the reversible adsorption of aqueous wastes; and

e The mobile plasma pyrolysis unit.

Most of the work on these projects is done outside the EPA organization, thus cooperation with industry and universities is essential to the agency's continued . history of success in working with the private sector.

9-9 Thermal Destruction Research Proaram

The Thermal Destruction Research Program has been operating for six years centered in the Alternative Technologies Division of the Hazardous Waste Engineering Research Laboratory in Cincinnati , Ohio. The research programs support activities to develop regulations that ensure safe disposal of hazardous materials in thermal destruction processes; provide guide1 ines for operating hazardous waste thermal destruction facilities; and, establish an engineering relationship to monitor compliance of permitted facilities. Research on thermal destruction methods using industrial kilns, incinerators, and boilers has been conducted.

Through their high-temperature combustion process, industrial kilns provide a large number of potential sites for the destruction of hazardous wastes. A series of eight tests on kilns has been performed. With the exception of a drying kiln, the facilities were capable of providing 99.99% destruction of the waste. Particulate emissions did not change. Sulfur dioxide and hydrogen chloride increased in the recycled dust as waste load increased, but no dibenzo dioxins or dibenzo furans emissions were found. PIC'S emissions were generally less than POHC emissions. Lead and zinc emissions increased as waste load increased.

The research programs on incinerators defined base1 ine performance under normal conditions. Nine full-scale facilities were evaluated from 1981 through 1983. Base1 ine destruction and removal efficiency and the products of incomplete combustion were examined at various incinerator operating conditions and waste-feed characteristics.

Performance tests have been run on 11 industrial boilers used to destroy hazardous wastes. Forty-two waste fuel-fired tests were performed; at two of the sites 100% of the fuel was comprised of waste. At seven of the sites, a mixture of carbon tetrachl oride/chlorobenzene/trichloroethyl ene was added to the waste fuels to gain information on destruction efficiencies and cross-boiler comparisons.

The measured POHO destruction efficiencies were near the requirements of the RCRA Incinerator Regulation. Note that during these tests the boiler was not operated in a normal mode. Cases where low DRE were measured were caused by such things as improper placement of fuel guns in the burner ports. The PIC emissions were generally one or two orders of magnitude greater than POHC emissions. The average CO gaseous emissions were 18- to 4000-ppm at 3% oxygen oxygen, NOx emissions ranged from 40- to llOO-ppm, and TUHC emissions ranged from undetectable to 160 ppm.

9-10 The goals for future work which build on the past research are as follows.

0 To define an incinerator operating parameter (e.g. CO/THC ratio or CO/CO2 ratio) which correlates with system performance (e.g., DRE, PIC formation).

0 To provide the necessary scientific basis for choosing POHO's for specification in permits.

0 To further access the performance capabilities of existing or proposed hazardous waste thermal destruction devices.

0 To develop an understanding of thermal destruction chemistry and engineering so that the performance of full-scale thermal destruction devices can be assessed and characterized.

Currently, the Hazardous Waste Thermal Destruction Research Program is conducting research in "groups" in order to accomplish the goals stated above. One group of research is being performed as in-house research at the Center Hill Facility in Cincinnati together with another combustion research facility in Jefferson, Arkansas. A second group is comprised of a series of evaluations at full-scale facilities during transient conditions for the three types of equipment. And the third group of research concerns full-scale tests at facilities, with the intention of verifying theories devel oped from the in-house research.

Evaluations of innovative and emerging thermal processes for the destruction Of hazardous wastes (e.g ., as a pl asma-arc unit, a high-temperature electric furnace, a mol ten salt reactor , a supercri tical water destruction process, and a catalytic wet oxidation system) are being conducted as part of the Thermal Destruction Program. Figure 9-1 shows the funding history applied to the during the last six years.

A serious effort is underway to coordinate A1 ternative Technology Division research with that of other groups receiving funding from the EPA. A technical working panel composed of five national experts outside of EPA is meeting with EPA members to review technical aspects of their own research.

9-11 THERMAL DESTRUCTION 8 RESEARCH z-7 v) -6 0 2

2 3 114 a u3 3z 42 U I-x Wl

FY80 FY81 FY82 FY83 FY84 FY85 FY86

Figure 9-1 . Thermal Destruction Research

'I I REFERENCES 1. 1985 - 1989 Research of Development Program Plan, EPRI P-3930-SR, January, 1985.

9-13

Section 10

BIBLIOGRAPHY

Amberg, R.H. "Sludge Dewatering and Disposal in the Pulp and Paper Industry." Journal WPCF, vol. 56, August 1984.

Anderson, J., M. Ponte, S. Biuso, D. Brailey, J. Kantorek, and T Schink. "Evaluating Dewatering Alternatives.'' Biocycle, October 1984.

Argonne National Laboratory. "Proceedings of the U.S. Department of Energy, Energy Optimization of Water and Wastewater Management for Municipal and Industrial Applications Conference," ANLIEES-TM-96, vol . 2, August 1980. Bajaj, J.K.L. "Grinding the Tough Plastics at Cryogenic Temperatures." Plastics Design and Processing, February 1977.

Barber, T.P. "Effluent Treatment in Process Industries." Process Biochemistry, September 1970, pp. 52-66.

Basta, Nicholas. "Hazardous Waste Incineration: A Burning CPI Concern." Chemical Engineering_, March 3, 1986, pp. 21-26.

Bridgewater, A.V. and C.J. Mumford. Waste Recycling and Pollution Control Handbook .'I 1979.

Bridgewater, A.V. and C.J. Mumford. Waste Recycling and Pollution Control --Handbook. 1979. Butcher, M. "Tube Press Offers a Fine Solution." Iron and Steel International, December 1982.

A Compilation of Statistics on Solid Waste Management Within the UnitedI States. McLean, VA: JRB Associates, August 1981. EPA Contract No. 68=01-6000.

Crocker, A.W. "Evaluation of Sludge Dewatering Alternatives at a Metallurgical Refinery." Journal WPCF,- vol. 54, October 1982.

"Cryogenic Grinding: An Efficient Method for Recycl ing Scrap Rubber." Rubber World. June 1980.

"Cryogenic Recycling Technology Gets More Practical - Even for the Toughest of Material .I1 Modern Plastics, July 1981. Anonymous. "Cryogenic Scrap Processing." Iron and Steel. October 1971, pp. 346- 348.

Cunningham, J.A., N.D. Hazzard, and M.L. Smith. "Economical and Reliable Disposal of Sol id Waste by Combustion Engineering." Presented at International Conference on Prepared Fuel , February 1981.

Dombrowski , Cathy. "RCRA Dead1 ine May C1 ose Many Landfi 11s." I_-World Wastes, November 1985, pp. 36-38.

John C. Dyer and Nicholas A. Miynone. Handbook of Industrial Residues. 1983.

10-1 EPRI Journal , CS-2627, September 1982. I_ Exner, Jurgen H. Detoxication of Hazardous Wastes. Michigan: Ann Arbor Science Pub1 ishers, 1982.

the Fourth Life Sciences Symposium, October 1981.

Frable, Norman B. "Keep Scrap Quality High with Cryogenic Grinding." Plastics Engineering, May 1976,

"Freeze-and-Smash Process to Release the Value of Scrap." The Engineer, July 27, 1978.

Galka, R.J. "A Literature Survey on Sewage Sludge Dewatering Centrifuges." British Hydromechanics Research Association, February 1981.

Georgia Institute of Technology. "Evaluation of Process Systems for Effective Management of Aluminum Finishing Wastewaters and Sludges." Atlanta, GA: March 1984.

Governor's Office of ADDroDriate Technolosv of California. Toxic Waste Assessment Group. A1 ternatives to the Land Disposldi of Hazardous Waste. Sacramento, CA: California Office of State Printing, 1981.

Guide1 ines for Cofiring Refuse-Derived Fuel in Utility Boilers." EPRI Journal, November 1985. RD186-1.

Hanchak, Michael J. "Future Technologies for the Managment of Hazardous Wastes." Waste&, October 1984, pp. 24-26.

Irvine, Robert L., Stanley A. Sojka, and Joseph F. Colarvotolo. "Enhanced Biological Treatment of Leachates from Industrial Landfills." Hazardous Wastes, vol. 1, no. 1, 1984, pp. 123-135.

Knopp, Paul V. "Underground Tank Management." Pollution Engineering, September 1985, pp. 24-27.

"Laboratory Eva1 uation of the Impact of Drying and Screening on Refuse-Derived Fuel Quality." EPRI Journal, Apri 1 1981. CS-1802.

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