Preliminary development of a bench-scale treatment system for aerobic degradation of trichloroethylene

Trichloroethylene (TCE) is a volatile, chlorinated, aliphatic compound that has been used extensively as a general cleaning and degreasing solvent by the military and industry. This extensive use has resulted in its becoming one of the most predominant groundwater contaminants, of particular environmental concern because of its potential carcinogenicity and its recalcitrance. Although some decomposition has been reported under anaerobic conditions, the decomposition is slow and results in the production of other hazardous compounds, including dichloroethylenes and vinyl chloride (1,4,5). Aerobic degradation has been reported in soil columns exposed to natural gas, suggesting that methanotrophs may be capable of TCE degradation (6). We recently reported on the isolation of a gramnegative bacterium, designated strain G4 (2), that apparently utilizes the enzymatic machinery of an aromatic biodegradative pathway to detoxify TCE (3).