SCIENCE DOSSIER Biodegradability of chlorinated solvents and related chlorinated aliphatic compounds J. A. Field & R. Sierra-Alvarez University of Arizona December 2004 December 2004 This publication is the fifth in a series of Science Dossiers providing the scientific community with reliable information on selected issues. If you require more copies, please send an email indicating name and mailing address to [email protected]. The document is also available as a PDF file on www.eurochlor.org Science Dossiers published in this series: 1. Trichloroacetic acid in the environment (March 2002) 2. Chloroform in the environment: Occurrence, sources, sinks and effects (May 2002) 3. Dioxins and furans in the environment (January 2003) 4. How chlorine in molecules affects biological activity (November 2003) 5. Hexachlorobutadiene – sources, environmental fate and risk characterisation (October 2004) 6. Natural Organohalogens (October 2004) 7. Euro Chlor workshop on soil chlorine chemistry: workshop proceedings (November 2004) 8. Biodegradability of chlorinated solvents and related chlorinated aliphatic compounds (December 2004) Copyright & Reproduction The copyright in this publication belongs to Euro Chlor. No part of this publication may be stored in a retrieval system or transmitted in any form or by any means, electronic or mechanical, including photocopying or recording, or otherwise, without the permission of Euro Chlor. Notwithstanding these limitations, an extract may be freely quoted by authors in other publications subject to the source being acknowledged with inclusion of a suitable credit line or reference to the original publication. Table of Contents Foreword ............................................................................................................................................. 1 Summary ............................................................................................................................................. 3 1. Introduction ............................................................................................................................... 5 1.1 Sources.............................................................................................................................. 5 1.2 Principles of Biodegradation .............................................................................................. 5 1.3 Mechanisms of Dehalogenation ......................................................................................... 6 1.4 Scope of Review ................................................................................................................ 7 2. Chloromethanes ........................................................................................................................ 9 2.1 Introduction ........................................................................................................................ 9 2.2 Biodegradation of lower chlorinated methanes .................................................................. 9 2.2.1 Degradation of lower chlorinated methanes in the environment ................................... 9 2.2.2 Degradation of lower chlorinated methanes in engineered systems ............................. 9 2.2.3 Microbiology and biochemistry of lower chlorinated methane biodegradation .............. 9 2.3 Biodegradation of higher chlorinated methanes ............................................................... 11 2.3.1 Degradation of higher chlorinated methanes in the environment ................................ 11 2.3.2 Degradation of higher chlorinated methanes in engineered systems .......................... 11 2.3.3 Microbiology and biochemistry of higher chlorinated methane biodegradation ........... 12 3. Chloroethanes ......................................................................................................................... 15 3.1 Introduction ...................................................................................................................... 15 3.2 Biodegradation of lower chlorinated ethanes ................................................................... 15 3.2.1 Degradation of lower chlorinated ethanes in the environment .................................... 15 3.2.2 Degradation of lower chlorinated ethanes in engineered systems .............................. 15 3.2.3 Microbiology and biochemistry of lower chlorinated ethane biodegradation ............... 16 3.3 Biodegradation of higher chlorinated ethanes .................................................................. 18 3.3.1 Degradation of higher chlorinated ethanes in the environment ................................... 18 3.3.2 Degradation of higher chlorinated ethanes in engineered systems ............................. 18 3.3.3 Microbiology and biochemistry of higher chlorinated ethane biodegradation .............. 19 4. Chloroethenes ......................................................................................................................... 23 4.1 Introduction ...................................................................................................................... 23 4.2 Biodegradation of lower chlorinated ethenes ................................................................... 23 4.2.1 Degradation of lower chlorinated ethenes in the environment .................................... 23 4.2.2 Degradation of lower chlorinated ethenes in engineered systems .............................. 24 4.2.3 Microbiology and biochemistry of lower chlorinated ethene biodegradation ............... 24 4.3 Biodegradation of higher chlorinated ethenes .................................................................. 27 4.3.1 Degradation of higher chlorinated ethenes in the environment ................................... 27 4.3.2 Degradation of higher chlorinated ethenes in engineered systems ............................. 28 4.3.3 Microbiology and biochemistry of higher chlorinated ethene biodegradation .............. 29 5. Chlorofluorocarbons ............................................................................................................... 35 5.1 Introduction ...................................................................................................................... 35 5.2 Biodegradation of CFC and HCFC .................................................................................. 35 5.2.1 Degradation of CFC and HCFC in the environment .................................................... 35 5.2.2 Degradation of CFC in engineered systems ............................................................... 36 5.2.3 Microbiology and biochemistry of CFC biodegradation ............................................... 36 6. Chloroacetic Acids .................................................................................................................. 39 6.1 Introduction ...................................................................................................................... 39 6.2 Biodegradation of Chloroacetic acids .............................................................................. 39 6.2.1 Degradation of chloroacetic acid in the environment .................................................. 39 6.2.2 Degradation of CFC in engineered systems ............................................................... 39 6.2.3 Microbiology and biochemistry of chloroacetic acid biodegradation ............................ 40 7. Chloropropanes, Chloropropenes & Epichlorohydrin ......................................................... 43 7.1 Introduction ...................................................................................................................... 43 7.2 Biodegradation of chloropropanoids ................................................................................ 43 7.2.1 Degradation of chloropropanoids in the environment .................................................. 43 7.2.2 Degradation of chloropropanoids in engineered systems ........................................... 43 7.2.3 Microbiology and biochemistry of chloropropanoid biodegradation ............................. 44 8. Chlorobutadienes .................................................................................................................... 47 8.1 Introduction ...................................................................................................................... 47 8.2 Biodegradation of chlorobutadienes ................................................................................. 47 8.2.1 Degradation of chlorobutadienes in the environment .................................................. 47 8.2.2 Degradation of chlorobutadienes in engineered systems ............................................ 47 8.2.3 Microbiology and biochemistry of chlorobutadiene biodegradation ............................. 47 9. Summary & Conclusions ........................................................................................................ 49 9.1 Scope of Different Physiological Approaches to Biodegradation...................................... 49 9.2 Biodegradation per Chlorinated Compound Category ...................................................... 49 9.2.1 Chlorinated Methanes ................................................................................................. 50 9.2.2 Chlorinated Ethanes .................................................................................................... 50 9.2.3 Chlorinated Ethenes ...................................................................................................