DOCSLIB.ORG

Redutive Dehalogenation of Chlorinated Alkanes by Novel Bacteria at the Petroprocessor of Louisiana Inc

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Redutive Dehalogenation of Chlorinated Alkanes by Novel Bacteria at the Petroprocessor of Louisiana Inc Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2008 Redutive Dehalogenation of Chlorinated Alkanes by Novel Bacteria at the PetroProcessor of Louisiana Inc. Superfund Site Jun Yan Louisiana State University and Agricultural and Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Civil and Environmental Engineering Commons Recommended Citation Yan, Jun, "Redutive Dehalogenation of Chlorinated Alkanes by Novel Bacteria at the PetroProcessor of Louisiana Inc. Superfund Site" (2008). LSU Doctoral Dissertations. 510. https://digitalcommons.lsu.edu/gradschool_dissertations/510 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. REDUCTIVE DEHALOGENATION OF CHLORINATED ALKANES BY NOVEL BACTERIA AT THE PETROPROCESSOR OF LOUISIANA INC. SUPERFUND SITE A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agriculture and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Civil and Environmental Engineering by Jun Yan B.S., Nanjing University, China, 2000 M.S., Nanjing University, China, 2003 May 2009 ACKNOWLEDGMENTS I would like to take this opportunity to express my sincere appreciation to my advisor, Dr. William M. Moe, for offering me such a great opportunity to complete my Ph.D. research under his direction. During my study at LSU, I have enjoyed my research on this project in Dr. Moe’s group. His insightful guidance and generous support always inspire my research and encourage me to pursue the accomplishments of my career. I would like to acknowledge Dr. Fred A. Rainey, for his instruction in the field of microbiology, molecular biology, and phylogenetic analysis in this research, and Dr. John H. Pardue for his instructions on GC-MS analysis of dehalogenation products. My appreciation is also given to Dr. W. David Constant and Dr. Mark Benfield for kindly serving on my dissertation committee. I would like to thank the former and current members in our research group, Dr. Congna Li, Dr. Bing Qi, Dr. Hee-Sung Bae, Dr. Brian Rash, Kimberly Bowman, Dr. Jyoti U Rao, and Marilou Nabatilan for their supports and friendship. I would also like to thank the members from Dr. Pardue’s group, Dr. Xingmao Ma, Dr. Han-Woong Lee, Stephen E. Mbuligwe and Dr. Eun- Ju Lee, and the members of Raineylab, Dr. Manish Shukala and Ryan Callegan. My appreciation also extends to Cindy Henk from the LSU Socolofsky Microscopy Center, and Dr. William G. Henk from the LSU School of Veterinary Medicine for assistance in preparing cell samples and taking microscopy (SEM and TEM) images of bacteria isolated in this research. Special thanks are given to Dr. Milton S. da Costa and his group from Universidade de Coimbra, Portugal, for analysis of DNA G+C content; Dr. Kenneth E. Damann, Jr. from the LSU Department of Plant Pathology and Crop Physiology, and Dr. Gregg S. Pettis and his graduate student, Dongli Guan from the LSU Department of Biological Sciences for assistance with PFGE. ii Finally, I express my deepest appreciation to my wife, Jie Zhu for her encouragement, support, love, and great cooking, and my parents, Aihua Li and Xiliang Yan, for their consistent support and unconditional love. iii TABLE OF CONTENTS ACKNOWLEDGMENTS ............................................................................................................ ii LIST OF TABLES ...................................................................................................................... vii LIST OF FIGURES ................................................................................................................... viii ABSTRACT…...................... ......................................................................................................... x CHAPTER 1. INTRODUCTION AND LITERATURE REVIEW ....................................... 1 1.1 Introduction ...................................................................................................................... 1 1.2 History and Overview ...................................................................................................... 1 1.3 Toxicological Properties .................................................................................................. 3 1.4 Remediation Technologies ............................................................................................... 4 1.5 Biodegradation and Bioavailability .................................................................................. 5 1.5.1 Chlorinated Solvent Biodegradation Under Aerobic Conditions ................................. 5 1.5.2 Chlorinated Solvent Biodegradation Under Anaerobic Conditions ............................. 6 1.6 Research Objectives ....................................................................................................... 13 1.7 Dissertation Organization ............................................................................................... 13 CHAPTER 2. ENRICHMENT AND ISOLATION OF ANAEROBIC REDUCTIVE DECHLORINATION BACTERIA FROM A SUPERFUND SITE ...................................... 14 2.1 Introduction .................................................................................................................... 14 2.2 Materials and Methods ................................................................................................... 14 2.2.1 Chemicals ................................................................................................................... 14 2.2.2 Groundwater Collection ............................................................................................. 15 2.2.3 Enrichment Culture..................................................................................................... 15 2.2.4 Bacterial Isolation ....................................................................................................... 16 2.2.5 DNA Extraction and 16S rRNA Gene Sequencing .................................................... 17 2.2.6 Analytical Methods..................................................................................................... 18 2.3 Results ............................................................................................................................ 18 2.3.1 Construction of Dehalogenation Enrichment Culture ................................................ 18 2.3.2 Isolation of Dehalogenating Bacteria and Phylogenetic Analysis .............................. 19 2.4 Discussion ...................................................................................................................... 21 2.5 Conclusions .................................................................................................................... 22 CHAPTER 3. CHARACTERIZATION OF TWO NOVEL DEHALOGENATING BACTERIA………………… ..................................................................................................... 24 3.1 Introduction .................................................................................................................... 24 3.2 Material and Methods ..................................................................................................... 24 3.2.1 Chemicals ................................................................................................................... 24 3.2.2 Culture and Growth Conditions .................................................................................. 24 3.2.3 Microscopy ................................................................................................................. 25 3.2.4 Denaturing Gradient Gel Electrophoresis (DGGE) .................................................... 25 3.2.5 Southern Blotting ........................................................................................................ 27 iv 3.2.6 16S rRNA Gene Sequencing and Phylogenetic Analysis .......................................... 27 3.2.7 Dechlorination Activities ............................................................................................ 28 3.2.8 Growth, Biochemical Characteristics ......................................................................... 28 3.2.9 Oxygen and Salt Tolerance Test ................................................................................. 29 3.2.10 Pulsed Field Gel Electrophoresis (PFGE) ............................................................... 30 3.2.11 G+C Content of DNA ............................................................................................. 31 3.2.12 qPCR ....................................................................................................................... 31 3.2.13 Analytical Methods ................................................................................................. 32 3.3 Results ............................................................................................................................ 32 3.3.1 Morphology and Culture Purity .................................................................................. 32 3.3.2 Phylogenetic Analysis ................................................................................................ 33 3.3.3 Dehelogenating Activities .........................................................................................
Load more

Recommended publications
  • Chlorinated Solvent Bioremediation: Fundamentals and Practical Application for Remedial Project Managers Presented By: Christopher Marks, Ph.D
    Chlorinated Solvent Bioremediation: Fundamentals and Practical Application for Remedial Project Managers Presented by: Christopher Marks, Ph.D. & Carolyn Acheson, Ph.D. US Environmental Protection Agency Office of Research and Development National Risk Management Research Laboratory CLU-IN Webinar Nov. 14, 2018 Source: Accelerated Bioremediation of Chlorinated Solvents, Interstate Technology and Regulatory Council and Remediation and Technology Development Forum, 2003 1 Bioremediation of Chlorinated Solvents Source: Accelerated Bioremediation of Chlorinated Solvents, Interstate Technology and Regulatory Council and Remediation and Technology 2 Development Forum, 2003 Part I: Introduction to Chlorinated Solvent Properties and Anaerobic Reductive Dechlorination 3 Terminology • Anaerobic: Microbial metabolic processes occurring in the absence of oxygen. • Anaerobic Reductive Dechlorination: The biological removal of a chlorine atom from an organic compound and replacement with a hydrogen atom in a reducing environment. • Biodegradation aka biotransformation: Biologically mediated reactions which convert one chemical to another. For example, PCE is converted to TCE when anaerobic reductive reactions remove a chlorine molecule. • Bioremediation: The engineered approaches using microorganisms to biodegrade contaminants. • Biostimulation: The addition of organic electron donors and nutrients to enhance the rate of reductive dechlorination by the native microflora. • Bioaugmentation: The addition of beneficial microorganisms to enhance the capacity
    [Show full text]
  • Overview of in Situ Bioremediation of Chlorinated Ethene DNAPL Source Zones
    INTERSTATE TECHNOLOGY & REGULATORY COUNCIL Warning! This document has not been amended since publication. Some content may be out of date and may no longer apply. INTERSTATE TECHNOLOGY & REGULATORY COUNCIL Technology Overview Overview of In Situ Bioremediation of Chlorinated Ethene DNAPL Source Zones October 2005 Prepared by The Interstate Technology & Regulatory Council Bioremediation of DNAPLs Team ABOUT ITRC Established in 1995, the Interstate Technology & Regulatory Council (ITRC) is a state-led, national coalition of personnel from the environmental regulatory agencies of more than 40 states and the District of Columbia, three federal agencies, tribes, and public and industry stakeholders. The organization is devoted to reducing barriers to and speeding interstate deployment of, better, more cost-effective, innovative environmental techniques. ITRC operates as a committee of the Environmental Research Institute of the States (ERIS), a Section 501(c)(3) public charity that supports the Environmental Council of the States (ECOS) through its educational and research activities aimed at improving the environment in the United States and providing a forum for state environmental policy makers. More information about ITRC and its available products and services can be found on the Internet at www.itrcweb.org. DISCLAIMER This document is designed to help regulators and others develop a consistent approach to their evaluation, regulatory approval, and deployment of specific technologies at specific sites. Although the information in this document is believed to be reliable and accurate, this document and all material set forth herein are provided without warranties of any kind, either express or implied, including but not limited to warranties of the accuracy or completeness of information contained in the document.
    [Show full text]
  • Considerations for the Collection and Evaluation of Natural Attenuation Parameters at Sites Contaminated with Chlorinated Solvents
    CONSIDERATIONS FOR THE COLLECTION AND EVALUATION OF NATURAL ATTENUATION PARAMETERS AT SITES CONTAMINATED WITH CHLORINATED SOLVENTS Chlorine • Hydrogen • Carbon • Bond "\. ( . I Vinyl Chloride I . ~ I Cis-1,2-Dichloroethene I ITrichloroethene I .,. Source Area Biological Active Area DowngradientI Area Filure 3 Anaerobic Reductive Dechlorination ofa Trichloroethene Plnm.e Prepared by Florida Department of Environmental Protection (FDEP) Division of Waste Management Bureau of Waste Cleanup Hazardous Waste Cleanup Section April 1999 TABLE OF CONTENTS SECTION TITLE PAGE 1.0 IN'TR.ODUCTION ........................................................................................ 1 ~ 2.0 GENERAL OVERVIEW OF CHLORINATED ALIPHATIC HYDROCARBON BIODEGRADATION................................................. 2 2.1 Bacteria 2.2 Electron Acceptor Reactions 2.3 Electron Donor Reactions 2.4 Co-Metabolism 3.0 NATURAL ATTENUATION BY PHYSICAL PROCESSES ................... 4 4.0 METABOLIC BY-PRODUCTS AND REDOX PROCESSES IN GROUNDWATER SYSTEMS ................................................................... 4 S.O EVIDENCE USED TO SUPPORT NATURAL ATTENUATION•••••••••• S 5.1 Direct Evidence S.2 Examine Changes 5.3 Laboratory microcosm studies 6.0 METHODOLOGY USED FOR DATA REVIEW AND SITE EVALUATION........................................................................................... 6 7.0 NATURAL ATTENUATION SAMPLING AND DATA EVALUATION METHODOLOGY..................................................................................... 9 7.1 Monitor Well
    [Show full text]
  • Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents
    FINAL Principles and Practices of Enhanced Anaerobic Bioremediation of Chlorinated Solvents August 2004 This page intentionally left blank PRINCIPLES AND PRACTICES OF ENHANCED ANAEROBIC BIOREMEDIATION OF CHLORINATED SOLVENTS August 2004 Prepared for: Air Force Center for Environmental Excellence Brooks City-Base, Texas Naval Facilities Engineering Service Center Port Hueneme, California and Environmental Security Technology Certification Program Arlington, Virginia This page intentionally left blank ACKNOWLEDGEMENTS The Parsons Corporation (Parsons) prepared this Principles and Practices document under contract to the Air Force Center for Environmental Excellence (AFCEE, Contract F41624-00- D-8024) and the Naval Facilities Engineering Service Center (NFESC, Contract N47408-98- D-7527). The NFESC contract was funded by the Environmental Security Technology Certification Program (ESTCP). The United States Army Corp of Engineers (USACE) assisted with technical review. This document is intended to assist AFCEE, NFESC, ESTCP, USACE and their United States (US) Department of Defense (DoD) technology-transition partners in evaluating and applying enhanced in situ anaerobic bioremediation for restoration of groundwater contaminated with chlorinated solvents. The authors acknowledge the assistance of numerous individuals who provided review services, and to several environmental contractors that provided case studies and information regarding respective areas of expertise. These individuals and their affiliations are listed in Appendix A. - i - 022/738863/28.doc DISCLAIMER In no event shall either the United States Government or Parsons have any responsibility or liability for any consequences of any use, misuse, inability to use, or reliance on the information contained herein; nor does either warrant or otherwise represent in any way the accuracy, adequacy, efficacy, or applicability of the contents hereof.
    [Show full text]
  • Biochemistry and Physiology of Halorespiration by Desulfitobacterium Dehalogenans
    Biochemistry and Physiology of Halorespiration by Desulfitobacterium dehalogenans ..?.^TJ?*LE_ LANDBOUWCATALOGU S 0000 0807 1728 Promotor: Dr.W.M . deVo s hoogleraar in de microbiologie Co-promotoren: Dr.ir .A.J.M .Stam s universitair hoofddocent bij deleerstoelgroe p Microbiologie Dr.ir . G. Schraa universitair docent bij deleerstoelgroe p Microbiologie Stellingen 1. Halorespiratie is een weinig efficiente wijze van ademhalen. Dit proefschrift 2. Halorespiratie moet worden opgevat als verbreding en niet als specialisatie van het genus Desulfitobacterium. Dit proefschrift 3. Reductieve dehalogenases zijn geen nieuwe enzymen. 4. 16S-rRNA probes zijn minder geschikt voor het aantonen van specifieke metabole activiteiten in een complex ecosysteem. Loffler etal. (2000) AEM66 : 1369;Gottscha l &Kroonema n (2000)Bode m3 : 102 5. Het "twin-arginine" transportsysteem wordt niet goed genoeg begrepen om op basis van het voorkomen van het "twin-arginine" motief enzymen te lokaliseren. Berks etal. (2000)Mol .Microbiol .35 : 260 6. Asbesthoudende bodem is niet verontreinigd. 7. Biologische groente is een pleonasme. Stellingen behorende bij het proefschrift 'Biochemistry and physiology of halorespiration by Desulfitobacterium dehalogenans' van Bram A. van de Pas Wageningen, 6 december 2000 MJOQ^O \lZ°]0 ^ Biochemistry and Physiology of Halorespiration by Desulfitobacterium dehalogenans BramA. van de Pas Proefschrift ter verkrijging van de graad van doctor op gezag van derecto r magnificus van Wageningen Universiteit, dr. ir. L. Speelman, in het openbaar
    [Show full text]
  • The Influence of In-Situ Activated Carbon on Biodegradation of Chlorinated Solvents
    Clemson University TigerPrints All Theses Theses 8-2018 The nflueI nce of In-Situ Activated Carbon on Biodegradation of Chlorinated Solvents Kameryn McGee Clemson University, [email protected] Follow this and additional works at: https://tigerprints.clemson.edu/all_theses Recommended Citation McGee, Kameryn, "The nflueI nce of In-Situ Activated Carbon on Biodegradation of Chlorinated Solvents" (2018). All Theses. 2925. https://tigerprints.clemson.edu/all_theses/2925 This Thesis is brought to you for free and open access by the Theses at TigerPrints. It has been accepted for inclusion in All Theses by an authorized administrator of TigerPrints. For more information, please contact [email protected]. THE INFLUENCE OF IN-SITU ACTIVATED CARBON ON BIODEGRADATION OF CHLORINATED SOLVENTS A Thesis Presented to the Graduate School of Clemson University In Partial Fulfillment of the Requirements for the Degree Master of Science Environmental Engineering and Earth Sciences by Kameryn McGee August 2018 Accepted by: Dr. Kevin Finneran, Committee Chair Dr. David Ladner Dr. Sudeep Popat ABSTRACT Chlorinated solvents have been a contaminant of interest in the remediation field for many years because they have been manufactured in large amounts and released into the environment due to improper storage and disposal. Since they are produced in such large quantities and there has been so many cases of uncontrolled releases, corrective actions are necessary and many remediation strategies have been explored. In- situ bioremediation of chlorinated solvents (TCE) is an intricate respiratory process which combines the addition of electron donors, chemical reactions, and the presence of microorganisms which directly access contaminants. Microbes metabolize the electron donor and utilize the energy for complete dechlorination of TCE to ethene.
    [Show full text]
  • Electron Donor and Acceptor Utilization by Halorespiring Bacteria'
    Electron donor andaccepto r utilizationb y halorespiring bacteria Maurice L.G.C. Luijten CENTRALS LANDBOUWCATALOGUS 0000 0950 9080 Promotoren Prof.dr .W.M . de Vos Hoogleraar ind eMicrobiologi c Wageningen Universiteit Prof.dr .ir .A.J.M .Stam s Persoonlijk hoogleraar bij hetlaboratoriu mvoo r Microbiologic Laboratorium voor Microbiologic, Wageningen Universiteit Copromotoren Dr.G .Schra a Universitair docent Laboratorium voor Microbiologic, Wageningen Universiteit Dr.A.A.M . Langenhoff Senior researcher/project leader Milieubiotechnologie, TNO-MEP Promotiecommissie Prof. E.J.Bouwe r John's Hopkins University, Baltimore, USA Prof.dr .C .Hollige r EPFL, Lausanne, Switzerland Dr.F .Volkerin g Tauw bv, Deventer, Nederland Prof. dr.ir .W.H . Rulkens Wageningen Universteit Dit onderzoek is uitgevoerd binnen de onderzoekschool SENSE (Netherlands Research School forth e Socio-Economic andNatura l Sciences ofth e Environment). LV''-:- v. •:-:::'.Ifir Electron donor and acceptor utilizationb y halorespiring bacteria Maurice L.G.C.Luijte n Proefschrift Terverkrijgin g van de graadva n doctor opgeza gva n derecto r magnificus van Wageningen Universiteit, prof. dr. ir. L. Speelman, inhe t openbaar te verdedigen opvrijda g 11 juni 2004 desnamiddag s te half twee in deAula . \ '\ i ocXi ^ Electron donor and acceptor utilization byhalorespirin g bacteria Maurice L.G.C. Luijten Ph.D.thesi sWageninge n University, Wageningen, The Netherlands 2004 ISBN 90-5804-067-1 Front cover: Modified EMpictur e ofSulfurospirillum halorespirans PCE-M2 — ry ' Stellingen 1.El k nadeel heb zijn voordeel. Dit proefschrift. 2. De ene volledige reductie van PCE is de andere nog niet. Dit proefschrift. 3. Sectorale communicatie reikt niet ver genoeg. HRH the Prince of Orange, Wat.
    [Show full text]
  • Recent Strategies for Environmental Remediation of Organochlorine Pesticides
    applied sciences Review Recent Strategies for Environmental Remediation of Organochlorine Pesticides Timothy O. Ajiboye 1,2 , Alex T. Kuvarega 3 and Damian C. Onwudiwe 1,2,* 1 Material Science Innovation and Modelling (MaSIM) Research Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, South Africa; [email protected] 2 Department of Chemistry, School of Physical and chemical Sciences, Faculty of Natural and Agricultural Sciences, North-West University, Mafikeng Campus, Private Bag X2046, Mmabatho 2735, South Africa 3 Nanotechnology and Water Sustainability Research Unit, College of Science, Engineering and Technology, University of South Africa, Florida 1709, South Africa; [email protected] * Correspondence: [email protected]; Tel.: +27-18-389-2545; Fax: +27-18-389-2420 Received: 29 June 2020; Accepted: 27 July 2020; Published: 10 September 2020 Abstract: The amount of organochlorine pesticides in soil and water continues to increase; their presence has surpassed maximum acceptable concentrations. Thus, the development of different removal strategies has stimulated a new research drive in environmental remediation. Different techniques such as adsorption, bioremediation, phytoremediation and ozonation have been explored. These techniques aim at either degrading or removal of the organochlorine pesticides from the environment but have different drawbacks. Heterogeneous photocatalysis is a relatively new technique that has become popular due to its ability to completely degrade different toxic pollutants—instead of transferring them from one medium to another. The process is driven by a renewable energy source, and semiconductor nanomaterials are used to construct the light energy harvesting assemblies due to their rich surface states, large surface areas and different morphologies compared to their corresponding bulk materials.
    [Show full text]
  • Reductive, Dechlorination of Sediment-Sorbed Polychlorinated
    AN ABSTRACT OF THE THESIS OF Darin James Trobaugh for the degree of Master of Science in Civil Engineering presented on July 1, 1998. Title: Reductive Dechlorination of Sediment-Sorbed Polychlorinated Biphenyls by Vitamin B12s. Redacted for Privacy Abstract approved.:--- Sandra L. Woods The reductive dechlorination of chlorobiphenyls in sediment by titanium(III) citrate-reduced vitamin Bus was studied in batch reactors. Long term ampoule studies demonstrated reductive dechlorination of sediment-sorbed 2,3,4,5,6-pentachlorobiphenyl (2,3,4,5,6-PeCB) to tetra-, tri-, di-, and monochlorobiphenyl products. Over 50% chlorine removal was observed over 160 days. The results of the ampoule experiment were compared to previous experiments with aqueous PCBs, and both systems appeared to follow the same pathway. Theoretical product distributions based on free energies of formation were compared to product distributions for the ampoule experiments, and both aqueous and sediment-sorbed PCB reductive dechlorination followed the thermodynamically favored pathway. Although chlorines were removed from all positions, reductive dechlorination was generally preferred at the ortho position. Reductive Dechlorination of Sediment-Sorbed Polychlorinated Biphenyls by Vitamin B12s by Darin James Trobaugh A THESIS submitted to Oregon State University In partial fulfillment of the requirements for the degree of Master of Science Presented July 1, 1998 Commencement June 1999 Master of Science thesis of Darin James Trobaugh presented on July 1, 1998 APPROVED: Redacted for Privacy ajor Professor, representing Civil Engineering Redacted for Privacy Chair of Department of Civil, Construction, and Environmental Engineering Redacted for Privacy Dean of Grad e School I understand that my thesis will become part of the permanent collection of Oregon State University libraries.
    [Show full text]
  • Guidelines: Natural Attenuation of Chlorinated Solvents in Ground Water
    GUIDELINES NATURAL ATTENUATION OF CHLORINATED SOLVENTS IN GROUND WATER MINNESOTA POLLUTION CONTROL AGENCY SITE REMEDIATION SECTION © Minnesota Pollution Control Agency 2006 © Minnesota Pollution Control Agency 2006 TABLE OF CONTENTS EXECUTIVE SUMMARY ................................................................................................................................... III 1.0 SCREENING FOR NATURAL ATTENUATION.......................................................................................5 Screening for chlorinated ethylenes ...................................................................................................................7 Screening for contaminants other than chlorinated ethylenes.........................................................................8 2.0 DETAILED SITE CHARACTERIZATION: REFINEMENT OF THE SITE CONCEPTUAL MODEL...................................................................................................................................................................10 3.0 RATE ANALYSIS: ESTIMATES OF SITE-SPECIFIC ATTENUATION KINETICS ........................11 3.1 Falling contaminant concentrations: source decay terms......................................................................11 3.2 Groundwater attenuation rates and biodegradation rate (lambda) calculations................................12 3.3 Calculation of a natural attenuation capacity term ...............................................................................13 4.0 ABIOTIC DEGRADATION.........................................................................................................................14
    [Show full text]
  • Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal
    water Article Reductive/Oxidative Sequential Bioelectrochemical Process for Perchloroethylene Removal Marco Zeppilli * , Edoardo Dell’Armi, Lorenzo Cristiani, Marco Petrangeli Papini and Mauro Majone Department of Chemistry, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy; [email protected] (E.D.); [email protected] (L.C.); [email protected] (M.P.P.); [email protected] (M.M.) * Correspondence: [email protected]; Tel.: +39-064-9913716; Fax: +39-064-90631 Received: 31 October 2019; Accepted: 4 December 2019; Published: 6 December 2019 Abstract: An innovative bioelectrochemical reductive/oxidative sequential process was developed and tested on a laboratory scale to obtain the complete mineralization of perchloroethylene (PCE) in a synthetic medium. The sequential bioelectrochemical process consisted of two separate tubular bioelectrochemical reactors that adopted a novel reactor configuration, avoiding the use of an ion exchange membrane to separate the anodic and cathodic chamber and reducing the cost of the reactor. In the reductive reactor, a dechlorinating mixed inoculum received reducing power to perform the reductive dechlorination of perchloroethylene (PCE) through a cathode chamber, while the less chlorinated daughter products were removed in the oxidative reactor, which supported an aerobic dechlorinating culture through in situ electrochemical oxygen evolution. Preliminary fluid dynamics and electrochemical tests were performed to characterize both the reductive and oxidative reactors, which were electrically independent of each other, with each having its own counterelectrode. The first continuous-flow potentiostatic run with the reductive reactor (polarized at 450 mV vs. SHE) resulted − in obtaining 100% 1% removal efficiency of the influent PCE, while the oxidative reactor (polarized ± at +1.4 V vs.
    [Show full text]
  • Sustainability of Reductive Dechlorination at Chlorinated
    Sustainability of Reductive Dechlorination at Chlorinated Solvent Contaminated Sites: Metrics for Assessing Potentially Bioavailable Natural Organic Carbon in Aquifer Sediments Lashun King Thomas Dissertation submitted to the faculty of the Virginia Polytechnic Institute and State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy In Civil Engineering Mark A. Widdowson, Chair John T. Novak Francis H. Chapelle Gregory D. Boardman Peter J. Vikesland 2 February 2011 Blacksburg, VA Keywords: Monitored Natural Attenuation, Potentially Bioavailable Organic Carbon, Chloroethenes, Reductive Dechlorination, Natural Organic Carbon Copyright © 2011 Lashun King Thomas 1 Sustainability of Reductive Dechlorination at Chlorinated Solvent Contaminated Sites: Metrics for Assessing Potentially Bioavailable Natural Organic Carbon in Aquifer Sediments Lashun King Thomas ABSTRACT Groundwater remediation strategies have advanced toward more effective and economical remedial technologies. Monitored natural attenuation (MNA) has become accepted by federal regulatory agencies as a viable remediation strategy for contaminants under site- specific conditions. At chloroethene contaminated sites where MNA is used as a remediation strategy, microbially-mediated reductive dechlorination is typically the dominant pathway for natural attenuation. The efficacy of reductive dechlorination at sites with no anthropogenic carbon sources is often influenced by the availability of readily-biodegradable natural organic carbon along with favorable geochemical conditions for supporting microbial dehalogenation. Recent research studies have suggested that the pool of labile natural organic carbon, operationally defined as potentially bioavailable organic carbon (PBOC), may be a critical component related to sustaining reductive dechlorination at MNA sites. The objective of this study was to evaluate PBOC as a quantitative measure of the labile organic carbon fraction of aquifer sediments in relation to microbial reductive dechlorination of chlorinated solvents.
    [Show full text]