Intrinsic biodegradation of trichloroethene and trichloroethane in a sequential anaerobic-aerobic aquifer
- Beak Consultants Ltd., Guelph, Ontario (Canada)
- Beak Consultants, Kirkland, WA (United States)
Trichloroethene (TCE) and 1,1,1-trichloroethane (1,1,1-TCA) are being intrinsically biodegraded in the groundwater near a former unlined septic-waste lagoon (former lagoon) at a site in Sacramento, California. Although the groundwater at the site is predominantly aerobic, groundwater in the immediate vicinity of the former lagoon is anaerobic. In the anaerobic zone, TCE and 1,1,1-TCA are being sequentially dechlorinated to ethene and ethane. However, the rate of dechlorination is not sufficient to prevent transport of TCE, 1,2-dichloroethene (1,2-DCE), vinyl chloride (VC), 1,1-DCA, and chloroethane (CA) from the anaerobic zone. In the aerobic zone, the lateral distributions of VC and CA are considerably smaller than the lateral distributions of the higher chlorinated volatile organic compounds (VOCs). Because VC and CA are more mobile in groundwater than the higher chlorinated VOCs, and therefore should have greater lateral distributions in the groundwater, the authors conclude that VC and CA are being biodegraded in the aerobic zone. These results provide field evidence for the intrinsic biodegradation of TCE and 1,1,1-TCA to nonchlorinated end products via two processes: (1) complete reductive dechlorination to ethene and ethane under anaerobic conditions; and (2) reductive dechlorination to VC or CA under anaerobic conditions, followed by biodegradation of VC and CA under aerobic conditions.
- OSTI ID:
- 464905
- Report Number(s):
- CONF-950483-; ISBN 1-57477-002-0; TRN: IM9720%%120
- Resource Relation:
- Conference: 3. international in situ and on-site bioreclamation symposium, San Diego, CA (United States), 24-27 Apr 1995; Other Information: PBD: 1995; Related Information: Is Part Of Intrinsic bioremediation; Hinchee, R.E. [ed.] [Battelle Memorial Inst., Columbus, OH (United States)]; Wilson, J.T. [ed.] [Environmental Protection Agency, Ada, OK (United States). Ground Water Protection and Remediation Div.]; Downey, D.C. [ed.] [Parsons Engineering Science, Inc., Denver, CO (United States)]; PB: 276 p.; Bioremediation, Volume 3(1)
- Country of Publication:
- United States
- Language:
- English
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