title: Assessment of potential anaerobic biotransformation of organic pollutants in sediment caps.
abstract: In situ capping is a remedial approach for reducing the risk of biota exposure to sediment contaminants. Biotransformation of contaminants in sand-based sediment caps, rarely considered in sediment cap design, could further reduce the exposure risk. The anaerobic biotransformation of benzene, toluene, ethylbenzene, xylenes (BTEX), monochlorobenzene, dichlorobenzenes and naphthalene was evaluated with sediments from Onondaga Lake in dilute sediment slurries and in sand-capped sediment laboratory-scale columns. The percentage of sediment samples demonstrating biotransformation under anaerobic conditions in slurries incubated at 12°C was greatest for BTEX, followed by monochlorobenzene, 1,4-dichlorobenzene, 1,2-dichlorobenzene and 1,3-dichlorobenzene. Only toluene biotransformation was observed in sand cap columns. The rate of toluene biotransformation diminished over time, which might be due to inhibition caused by hydrogen from the experimental setup. Results suggest potential for the biotransformation of toluene, and possibly other pollutants, in sand-based sediment caps under anaerobic conditions at low temperatures.
authors: Department of Civil, Architectural, and Environmental Engineering, The University of Texas at Austin, TX, USA. tsmith@geosyntec.com
authors: Anthony M
authors: AM
authors: Smith
authors: Mary Jo
authors: MJ
authors: Kirisits
authors: Danny D
authors: DD
authors: Reible
mesh_terms: D000693:Anaerobiosis; D001105:Archaea / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism; D001711:Biotransformation; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology; D060106:Lakes / Q000737:chemistry / Q000382:microbiology; D009518:New York; D009930:Organic Chemicals / Q000378:metabolism*; D016062:Porosity; D017422:Sequence Analysis, DNA; D012722:Sewage / Q000382:microbiology; D012822:Silicon Dioxide; D013997:Time Factors; D014050:Toluene / Q000378:metabolism; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D009930:Organic Chemicals; D012722:Sewage; D014874:Water Pollutants, Chemical; D014050:Toluene; D012822:Silicon Dioxide