Anaerobic microbial transformation of aromatic hydrocarbons and mixtures of aromatic hydrocarbons and halogenated solvents. Final report, 30 September 1988-31 March 1992
Anaerobic microbial transformation of monoaromatic hydrocarbons (NM), chlorinated benzenes (CB), and mixtures of MAH and CB, as well as MAH and chlorinated aliphatic solvents (tetrachloroethylene -- PCE, and carbon tetrachloride -CT) was studied in laboratory microcosms derived from hydrocarbon-contaminated groundwater aquifers. Some MAH , such as toluene and o-xylene, were completely degraded to CO 2 and CH by mixed methanogenic cultures from a creosote-contaminated aquifer. This degradation was inhibited by the addition of accessory electron acceptors (oxygen, nitrate, sulfate), indicating acclimation of the microbial community to methanogenic conditions. The addition of preferred substrates, such as acetate, propionate, methanol, fatty acids, glucose, casamino acids, pepton, yeast extract, or acetone also inhibited MAH degradation, indicating that the presence of natural organic substrates may preclude anaerobic biodegradation of in situ. Cyclohexane, CT, and high concentrations of toluene and o-xylene had a toxic effect. Under sulfate-reducing conditions, several MAH -- toluene, all three xylene isomers, and benzene were mineralized to CO by microorganisms from a petroleum-contaminated, sulfidogenic aquifer. Whereas 2 toluene and xylenes were sequentially degraded in a mixture, benzene was degraded only if alone, or slowly transformed in a mixture with toluene. This explains previously reported recalcitrance of benzene under anaerobic conditions. The addition of preferred substrates (lactate, glucose, or yeast extract) to the cultures temporarily inhibited the degradation of MAH. Methanogenic microcosms from the creosote-contaminated aquifer reductively dechlorinated hexa-, penta-, tetra-, tri-, and di-chlorobenzene.
- Research Organization:
- Stanford Univ., CA (United States). Dept. of Civil Engineering
- OSTI ID:
- 6599419
- Report Number(s):
- AD-A-260498/1/XAB; CE-319; CNN: AFOSR-88-0351
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
02 PETROLEUM
GROUND WATER
CONTAMINATION
HALOGENATED AROMATIC HYDROCARBONS
BIODEGRADATION
ACETATES
ACETONE
ANAEROBIC CONDITIONS
AQUIFERS
AROMATICS
ATMOSPHERES
BENZENE
CARBON DIOXIDE
CARBON TETRACHLORIDE
CARBOXYLIC ACIDS
CHLORINE COMPOUNDS
CHLOROFORM
COMMUNITIES
CREOSOTE
CYCLOHEXANE
ETHYLENE
GLUCOSE
HYDROCARBONS
ISOMERS
LABORATORIES
LACTATES
METABOLITES
METHANE
METHANOL
MICROCOSMS
MICROORGANISMS
MICROSCOPY
NITRATES
OXYGEN
PETROLEUM
PETROLEUM INDUSTRY
RESEARCH PROGRAMS
SOLVENTS
SUBSTRATES
SULFATES
TOLUENE
TOXICITY
XYLENES
YEASTS
ALCOHOLS
ALDEHYDES
ALKANES
ALKENES
ALKYLATED AROMATICS
CARBOHYDRATES
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACID SALTS
CHALCOGENIDES
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
CYCLOALKANES
DECOMPOSITION
ELEMENTS
ENERGY SOURCES
EUMYCOTA
FOSSIL FUELS
FUELS
FUNGI
HALOGEN COMPOUNDS
HALOGENATED ALIPHATIC HYDROCARBONS
HEXOSES
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
INDUSTRY
KETONES
MONOSACCHARIDES
NITROGEN COMPOUNDS
NONMETALS
ORGANIC ACIDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLANTS
SACCHARIDES
SULFUR COMPOUNDS
WATER
540220* - Environment
Terrestrial- Chemicals Monitoring & Transport- (1990-)
320305 - Energy Conservation
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