Anaerobic microbial transformation of aromatic hydrocarbons and mixtures of aromatic hydrocarbons and halogenated solvents. Final report, 30 Sep 88-31 Mar 92

Technical Report · Tue Aug 25 04:00:00 EDT 1992

OSTI ID:6901698

Edwards, E A; Liang, L N; Grbic-Galic, D

Anaerobic microbial transformation of monoaromatic hydrocarbons (MAH), 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 CO2 and CH4 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 MAH 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 CO2, by microorganisms from a petroleum-contaminated, sulfidogenic aquifer. Whereas-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.

• Research Organization: Stanford Univ., CA (United States). Dept. of Civil Engineering
• OSTI ID: 6901698
• Report Number(s): AD-A-255696/7/XAB; CNN: AFOSR-88-0351
• 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.
ANAEROBIC CONDITIONS
AQUIFERS
AROMATICS
BIODEGRADATION
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
CHLORINATED AROMATIC HYDROCARBONS
CLEANING
CREOSOTE
DECOMPOSITION
DECONTAMINATION
DISPERSIONS
HALOGENATED ALIPHATIC HYDROCARBONS
HALOGENATED AROMATIC HYDROCARBONS
HYDROCARBONS
MICROCOSMS
MICROORGANISMS
MIXTURES
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
POLLUTION
SOLVENTS
SUBSTRATES
WATER POLLUTION