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Kinetics of chlorinated ethylene dehalogenation under methanogenic conditions
Author(s) -
Skeen Rodney S.,
Gao Jianwei,
Hooker Brian S.
Publication year - 1995
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260480614
Subject(s) - methanogenesis , chemistry , halogenation , tetrachloroethylene , methanol , trichloroethylene , reductive dechlorination , ethylene , chlorine , dehalococcoides , methane , environmental chemistry , halocarbon , organic chemistry , inorganic chemistry , nuclear chemistry , biodegradation , catalysis , vinyl chloride , polymer , copolymer
Kinetics were determined for methanogenic activity and chlorinated ethylene dehalogenation by a methanol‐enriched, anaerobic sediment consortium. The culture reductively dechlorinated perchloroethylene (PCE) to trichloroethylene (TCE), 1,1‐dichloroethylene (1,1‐DCE), vinylchloride (VC), and ethylene and ethane. The absence : of methanol or the addition of 2‐bromoethanesulfonic. acid in the presence of methanol suppressed both methanogenic activity and dechlorination. In contrast, acetate production continued in the presence of 2‐bromoethanesulfonic acid. These results suggest that dechlorination was strongly linked to methane formation and not to acetate production. A kinetic model, developed to describe both methanogenesis and dechlorination, successfully predicted experimentally measured concentrations of biomass, methane, substrate, and chlorinated ethylenes. The average maximum specific dehalogenation rates for PCE, TCE, 1,1‐DCE, and VC were 0.9 ± 0.6, 0.4 ± 0.1, 12 ± 0.1, and 2.5 ± 1.7 μmol contaminant/ g. DW/day, respectively. This pattern for dechlorination rates is distinctly different than that reported for transition metal cofactors, where rates drop by approximately one order of magnitude as each successive chlorine is removed. The experimental results and kinetic analysis suggest that it will be impractical to targeting methanol consuming methanogenic organisms for in situ ground‐water restoration. © 1995 John Wiley & Sons, Inc.