Leachate Treatability Study HOD LANDFILL Antioch, Illinois r. „'- <••> ••• o ••» j^ V u v/v >• \.'l» Waste Management of North America- Midwest Two Westbrook Corporate Center • Suite 1000 • Westchester, Illinois 60154 Prepared by: RUST ENVIRONMENT & INFRASTRUCTURE, INC. Formerly SEC Donohve, Inc. Solid Waste Division 1240 Dichl Road • Naperville, Illinois 60563 • 708/955-6600 March 1993 Waste Management of North America- Midwest HOD LANDFILL LEACHATE TREATABILITY STUDY [; tr Project No. 70006 0 n I : ir • n [ J Prepared by: ! , RUST Environment & Infrastructure [ Formerfy SEC Donohue, Inc. ^ 1240 East Diehl Road n Naperville, Illinois 60563 MARCH 1993 0.0 Executive Summary A treatability study was conducted for HOD Landfill to determine the ability of a preliminary treatment facility design to reduce contaminants to limits acceptable for discharge to the City of Antioch POTW. Two pilot scale Sequencing Batch Reactors (SBRs) were operated at varying loading conditions between 0.1 and 0.7 g Chemical Oxygen Demand (COD)/g Mixed Liquor Volatile Suspended Solids (MLVSS) per day and the r reactors were monitored for treatability performance and optimal operating conditions. r: Optimal design/ operating conditions were evaluated during the study as well. The full- scale system should be designed with a loading of 0.2 gCOD/gMLVSS for conservative purposes. The reactor will be capable of successfully operating at varying loadings between 0.1-0.4 gCOD/gMLVSS with a pH range of 7.0-8.0 and temperature between 20-30 *C in the reactor. Table 11 presents the optimal design/operating conditions for the full-scale process. During higher loading conditions, pH control will be necessary to maximize the process efficiency and reduce effluent concentrations. In addition, when a high concentration of MLVSS is maintained in the reactor, sludge settling is hindered. Therefore, polymer n flocculant should be added prior to decanting the effluent, or the reactor can be initially fed under anoric conditions to decrease the population of poorly settling microorganisms. rV- ! Results of the study showed an average of >87% organic removal (as measured by Biological Oxygen Demand (BOD) and COD) and >90% ammonia reduction were achieved o at all loading conditions tested. Metals were reduced by > 95% and virtually no Total Toxic Organic (TTO) parameters (with the exception of 0.052 mg/1 chloromethane and 0.030 mg/1 o acetone), were detected in one sample. As seen in Table 11, all results showed excellent ii compliance with all limits established by the City of Antioch. NOTE: Bold items are defined in the Glossary (Appendix). II HOD LANDFILL LEACHATE TREATABILITY STUDY TABLE OF CONTENTS LIST OF TABLES / FIGURES / APPENDIX ............................ iii 6.0 Executive Summary ............................................. i 1.0 Introduction/Purpose ............................................ 1 2.0 Experimental Procedure .......................................... 2 2.1 Sampling/ Analytical Protocol ................................ 2 2.2 Reactor Description/ Operation .............................. 2 2.3 Feed Composition ......................................... 3 2.4 Data Collection ........................................... 4 2.5 Quality Assurance/ Quality Control (QA/QC) .................... 4 3.0 Experimental Results ..........................................:. 5 3.1 COD/BOD Reduction ...................................... 5 3.2 Ammonia Reduction ....................................... 5 3.3 Total Toxic Organic Results ................................. 6 3.4 Metals Reduction ......................................... 6 3.5 Operating Parameter Results ................................. 6 3.5.1 Sludge Age ......................................... 6 3.5.2 Sludge Yield ........................................ 6 3.5.3 Settleability ......................................... 8 4.0 Design/ Operation Recommendations ............................... 8 5.0 Summary/ Conclusions .......................................... 9 Ill HOD LANDFILL LEACHATE TREATABILITY STUDY LIST OF TABLES Table 1 Operational Schedule Table 2 Sampling/ Operational Protocol Table 3 Weekly Feed Composition Table 4 Influent Performance Data Table 5 Reactor 1 Performance Data Table 6 Reactor 2 Performance Data rr Table 7 Total Toxic Organics Table 8 Metals Removal Data Table 9 Sludge Yields Table 10 Leachate Treatability Summary Table 11 Design/ Operating Parameters D LIST OF FIGURES Figure 1 Reactor Design/ Set-up Figure 2 COD Removal tr Figure 3 Ammonia Removal Figure 4 Sludge Settling Characteristics- Reactor 1 R Figure 5 Sludge Settling Characteristics- Reactor 2 Figure 6 Design Loading Selection (COD/ Ammonia) APPENDIX APPENDIX GLOSSARY L 1.0 INTRODUCTION/ PURPOSE The purpose of this treatability study was to demonstrate the adequacy of the proposed HOD leachate pretreatment process and/or to develop modifications to the design to meet the discharge standards established by the Village of Antioch POTW. Initial analysis of HOD wastewater has previously indicated that it will be necessary to pretreat the wastewater to remove BOD, Suspended Solids, Iron, Zinc, and Ammonia/TKN. Additionally, it is desirable to minimize the discharge of Total Toxic Organics (TTO). TTO serves as an indicator of strength and toxicity for industrial discharges. While discharge standards are not specified for landfill leachates, 40CFR413.14 (f) (g) established an EPA industrial discharge guideline of 2.13-4.57 mg/1. A treatment process consisting of equalization followed by clarification and subsequent treatment via use of a Sequencing Batch Reactor (SBR) has been initially proposed for wastewater pretreatment. The SBR would be typically operated as an extended aeration, high sludge age system (> 25 days) to maximize treatment efficiency. However, two pilot scale reactors were operated at varying loading (0.1-0.7 gCOD/gMLVSS) conditions to determine the design performance at high and low loading rates. The treatability study was conducted over a nine week period, with five weeks for acclimization and four weeks for design/performance data collection. The study was originally designed to run seven weeks, however the acclimization period was extended by two weeks to achieve a steady MLVSS concentration. Influent leachate used during the study was taken from HOD's on-site storage tank, the east and west manholes, and piezometers 2A and 3A. NOTE: Bold items are defined in the Glossary (Appendix). BODLMOXOJ. 2.0 EXPERIMENTAL PROCEDURE 2.1 Leachate Sampling/ Analytical Protocol On Friday, December 4, a sampling team from RUST (formerly SEC Donohue) went to HOD Landfill in Antioch, Illinois to collect leachate to be used for the treatability study. Leachate was pulled from three areas of the landfill: twenty-five (25) gallons of leachate were composited from Piezometers 2A and 3A; twenty-five (25) gallons were composited from the East and West manholes; and twenty-five gallons (25) were pulled from the leachate storage tank on site which represents Piezometers 1, 8, 9, and 10. The leachate was immediately transported to the pilot study laboratory at CID Biological Treatment Facility (BTF) in Calumet City, Illinois and kept in cold storage (to inhibit natural biodegradation and prevent the release of volatile 0 compounds) for use during the nine week study. 0 Biomass used to seed the reactors at the beginning of the study was taken from the i CID's full scale SBR process which is already acclimated to leachates. Table 1 i.. describes the feed that was used during the two phases of the study, acclimatization, c and design data gathering. Table 2 provides the sampling analytical and operational x_ protocol for the study, as well as the laboratories used during the study. The reactors [ I were monitored daily for environmental conditions as well as compliance with the Antioch POTW standards. 22 Reactor Description/ Operation As seen in Figure 1, the two pilot study reactors were 6 liter glass containers with 0 loosely fitting plastic lids. Proper mixing conditions and oxygen levels were maintained by the use of mechanical mixers and aeration diffusers. Heating tubes were placed along the inside wall of the reactors to maintain a constant temperature NOTE: Bold items are defined in the Glossary (Appendix). BOD LANDFILL 3 of 20*C ± 5'C. Essential phosphorous levels were sustained at a ratio of 200:1 (COD:Phosphorous) by adding phosphoric acid. Excess nitrogen was already present in the reactors (as ammonia) so there was no need to supplement the feed in order to maintain the necessary 200:5 ratio of COD:Nitrogen. pH levels were regulated between 7.5 and 8.5 by adding hydrochloric acid to the reactors. Defoaming agent was used on an as-needed basis (typically 1 drop per day) to minimize sludge loss. f; Reactors 1 and 2 were operated in a batch mode, feeding 2.5 to 3 liters per cycle to each reactor with 3 to 5 cycles per week, depending on the feed composition (see n Section 2.3). Reactor 1 was designed to operate with a MLVSS concentration of 4,000 mg/1 and achieve a loading rate of 0.2 gCOD/gMLVSS-day. Reactor 2 was designed to operate with a MLVSS concentration of 2,000 mg/1 and to achieve a loading rate of and 0.4 gCOD/gMLVSS-day. Reactors were generally idle one day a week (Sunday) to facilitate monitoring and testing. o Both reactors were initially seeded with three (3) liters of sludge taken from CID's I full scale process and operated with an initial target 25 day sludge age. This was i; achieved by removing a predetermined