Biodegradation of Trihalomethanes and Other Halogenated Aliphatic Compounds

............................................................................................. vi JUSTIFICATION ........................................................................................ 1 METHODS ................................................................................................ 2 ..................................................................... RESULTS AND SIGNIFICANCE 4 .................................. Biological Dechlorination of Chloroform to Dichlorornethane 4 ............. Dichloromethane Degradation.. Correlation of Gene Probe and Activity Assays 8 Design and Function of a Two-stage Anaerobic Bioreactor to Degrade Chloroform ........ 12 Dehalogenation of ChlorofIuorocarbons (CFCs) by Aquifer Bacteria ........................ 14 ................................. Thermodynamic Parameters Used to Predict Dehalogenation 17 PRINCIPAL FINDINGS. CONCLUSIONS AND RECOMMENDATIONS .................. 18 SUMMARY ............................................................................................. 20 ............................................................................................ REFERENCES 21 LIST OF FIGURES AND TABLES .................................................. Figure 1 . Reductive Dechlorination of Chloroform 5 Figure 2 . Chloroform Dechlorination and Methanogenesis ........................................ 6 ................................. Figure 3 . Dechlorination and Methanogenesis Inhibition by BES 7 ............................................. Figure 4 . Reversal of BES Inhibition by Coenzyme M 7 .... Figure 5 . Dichloromethane Degradation by Hyphumicrobium and Wastewater Microbes 9 ........... Figure 6 . Hyphumicrobium and Wastewater Microbe DNA Hybridization Patterns 11 ............. Figure 7 . Two-stage Anaerobic Bioreactor Performance in Degrading Chloroform 13 ................................ Figure 8 . CFC Biodegradation Associated With Cellular Fraction 15 ............................... Figure 9 . CFC Degradation as Affected by CFC-11 Concentration 16 .............. Table 1 . Biological Dechlorination as Affected by Reaction Reduction Potential 18 ....................................... Table 2 . Summary of Biological Dehalogenation Reactions 20