Chemical activation of microbially-mediated PCB dechlorination: A novel approach to in situ remediatoin
- GE Corp. Research and Development, Schenectady, NY (United States); and others
Reductive dechlorination of polychlorinated biphenyls (PCBs) by anaerobic bacteria is potentially an important future option for in situ remediation of PCBs in aquatic sediments. We have developed a method to stimulate this activity. The method involves the addition of a brominated biphenyl or brominated benzoic acid to the sediment and is based on the hypothesis that this compound acts as a dehalogenation substrate and an electron acceptor for the indigenous PCB-dechlorinating bacteria and thereby stimulates PCB dechlorination. In a field test at Woods Pond (Lenox, MA), a site contaminated with Aroclor 1260, 2,6-dibromobiphenyl (2,6-BB) stimulated extensive meta-dechlorination of the PCBs and decreased the proportion of hexa- through nonachlorobiphenyls from 68 to 17.6 mole percent. The PCBs resulting from the dechlorination were primarily tri-, tetra-, and pentachlorobiphenyls containing 2,4- and 2,4,6-chlorophenyl groups. We have also identified a compound that can stimulate a second stage of dechlorination, removing para-chlorines from these PCBs and converting most of them to ortho- substituted di- and trichlorobiphenyls. The dechlorinated PCBs are far less persistent in the environment, more easily metabolized by higher organisms, and have lower bioaccumulation potential.
- OSTI ID:
- 126330
- Report Number(s):
- CONF-950402--
- Country of Publication:
- United States
- Language:
- English
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