Contaminant and organic matter bioavailability effects on the biotransformation of sediment-bound chlorobenzenes
- Georgia Institute of Technology, Atlanta, GA (United States)
The extent of reductive dechlorination taking place in contaminated, estuarine sediments was investigated. Specifically, the effect of contaminant and organic matter bioavailability on the reductive dechlorination of the sediment-bound chlorobenzenes was the main focus of the work presented here. Sediment and water samples were collected from a contaminated estuarine system. Hexachlorobenzene and other chlorinated benzene congeners were found to be the predominant chlorinated compounds. Anaerobic batch assays revealed that the sediment natural organic matter is recalcitrant and unable to support active microbial growth. Sediment nutrients (e.g., N.P.) were available in sufficient quantities to support an accelerated microbial growth. Static microcosms were constructed with sediment and water from the study site. The sediment microbial consortia were able to reductively dechlorinate the sediment-bound polychlorinated benzene congeners primarily to dichlorobenzene isomers. However, the extent of hexachlorobenzene removal over a long incubation time (more than 480 d) was only 43% and most of it occurred during the first 200 d of incubation. Both the recalcitrant nature of the sediment organic matter and the strong partitioning of the chlorinated compounds were responsible for the low extent of contaminant transformation. Addition of a degradable organic compound increased the extent of contaminant reductive dechlorination.
- OSTI ID:
- 416854
- Report Number(s):
- CONF-951023--
- Country of Publication:
- United States
- Language:
- English
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