Effects of three concentrations of mixed fatty acids on dechlorination of tetrachloroethene in aquifer microcosms

Journal Article · Tue Mar 01 04:00:00 EST 1994 · Environmental Toxicology and Chemistry; (United States)

DOI:https://doi.org/10.1002/etc.5620130313· OSTI ID:5056341

Gibson, S A; Roberson, D S ^[1]; Russell, H H ^[2]

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1. ManTech Environment Technology Inc., Ada, OK (United States)
2. Environmental Protection Agency, Ada, OK (United States). Robert S. Kerr Environmental Research Lab.

Chloroethenes are among the most common organic contaminants of ground water. The biotransformation of these compounds by reductive dechlorination is a promising technology for in situ treatment. The effects of three concentrations of a fatty acids mixture on the reductive dehalogenation of tetrachloroethane (PCE) were studied in methanogenic microcosms. These microcosms were constructed with slurries of aquifer solids collected from an area impacted both by aviation gasoline and chlorinated ethanes at Traverse City, Michigan. The microcosms were amended with approximately 30 [mu]M PCE and one of three concentrations of a mixture of low-molecular-weight organic axis, or were part of a control set that received no amendment. The observed lag or adaptation times before the onset of PCE dehalogenation were 51 d, 65 d, 86 d, and > 233 d (no acids). After 233 d of incubation, no PCE was detectable in any of the fatty-acid-supplemented microcosms, but 23 to 27 [mu]M of combined tri- and dichloroethenes (TCEs, DCEs) was detected. PCE was not dechlorinated in microcosms without a fatty acid supplement. Although there were observed differences in the length of the lag time, the amount of ultimately dechlorinated PCE was similar. A zero-order rate constant of 0.3 [mu]M d[sup [minus]1] was calculated for PCE dechlorination and for TCE dechlorination for the two series of microcosms receiving 0.1 and 1.0 mM fatty acid supplements. Of the fatty acids tested in the mixture, butyrate oxidation appeared to be the most probable link to PCE dechlorination.

• OSTI ID: 5056341
• Journal Information: Environmental Toxicology and Chemistry; (United States), Journal Name: Environmental Toxicology and Chemistry; (United States) Vol. 13:3; ISSN 0730-7268; ISSN ETOCDK
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
560300 -- Chemicals Metabolism & Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUIFERS
BIODEGRADATION
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
CLEANING
DECHLORINATION
DECOMPOSITION
DECONTAMINATION
DEHALOGENATION
GROUND WATER
HALOGENATED ALIPHATIC HYDROCARBONS
HYDROGEN COMPOUNDS
METABOLISM
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXYGEN COMPOUNDS
REMEDIAL ACTION
TECHNOLOGY ASSESSMENT
WATER