Accelerated biodegradation of PCBs
At one time it was thought that PCBs did not undergo biodegradation. However, in the past 10--15 years, PCBs have been shown to biodegrade via two distinct microbially mediated mechanisms: anaerobic dechlorination, which involves the removal of chlorine atoms and replacement by hydrogen atoms in the absence of oxygen; and aerobic biodegradation, which involves the oxidative destruction of PCB molecules through a series of degradation intermediates. The authors discuss the biodegradation of PCBs and focus on the benefits realized from anaerobic PCB dechlorination through conversion to less chlorinated PCB congeners that exhibit reduced dioxin-like toxicity, reduced carcinogenicity, and reduced exposure. The various commercially important PCBs can be characterized by congener-specific analysis using a gas chromatograph equipped with an electron capture detector. This chromatographic technique can also be used to distinguish processes such as dissolution into groundwater or alteration by microbial anaerobic dechlorination, both of which increase the relative levels of the lightly chlorinated congeners. The biological dechlorination of PCBs result in the production of ortho-enriched congeners that are present at low levels or absent in the original.
- OSTI ID:
- 99575
- Journal Information:
- CHEMTECH, Journal Name: CHEMTECH Journal Issue: 7 Vol. 25; ISSN CHTEDD; ISSN 0009-2703
- Country of Publication:
- United States
- Language:
- English
Similar Records
FeSO{sub 4} amendments stimulate extensive anaerobic PCB dechlorination
PCB biodegradation: Laboratory studies transitioned into the field