Anaerobic Degradation of C1 and C2 Chlorinated Hydrocarbons
Abstract
This research investigated the potential for anaerobic, biological degradation of five chlorinated C1 and C2 hydrocarbons: tetrachloroethylene (PCE), trichloroethylene (TCE), 1,1,1-trichloroethane (1,1,1-TCA), chloroform (CF), and dichloromethane (DCM). Attempts were made to delineate the importance of microbial -- as opposed to purely chemical -- mechanisms of degradation; products formed; and pathways involved. The five compounds were studied separately in batch, anaerobic systems employing a diverse community of microflora from a municipal waste treatment plant. The added substrate concentrations ranged from 2-25 mg/L for the C1 compounds, and from 1-2 mg/L for the C2 compounds. Radiotracer studies were conducted with 14C-chloroform and 14C-dichloromethane to investigate their fate, as well as to delineate degradative pathways. PCE was completely converted to TCE, but the product was not further degraded to any significant degree. Results suggest that the microbially mediated reductive dechlorination of PCE is an inducible process. Anaerobic conversion of 1,1,1-trichloroethane did not require acclimation. Anaerobic, microbial utilization of chloroform (CF) proceeded without acclimation. Microbial degradation of DCM occurred readily after an acclimation period of variable length. CF inhibits utilization of DCM in a manner that is slowly reversible. Inhibition persists long after levels of CF in the solution are depleted. Keywords: Biological Treatment; Hazardous Wastes; Solvents; Microbial Metabolism.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1985
- Accession Number
- ADA165005
Entities
People
- James M. Gossett