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Volatilization of extensively dechlorinated polychlorinated biphenyls from historically contaminated sediments
Author(s) -
Bushart Sean P.,
Bush Brian,
Barnard Edward L.,
Bott Amelie
Publication year - 1998
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.5620171006
Subject(s) - volatilisation , environmental chemistry , contamination , polychlorinated biphenyl , sediment , chemistry , biphenyl , soil contamination , water pollution , environmental science , geology , ecology , organic chemistry , paleontology , biology
A study was conducted as a preliminary characterization of the ability of Aroclor® 1248 polychlorinated biphenyl (PCB)‐contaminated sediments to volatilize PCBs into the air upon drying under conditions meant to be environmentally relevant. Sediments collected from the St. Lawrence River contained high levels (‐600 ppm) of PCBs. The PCB contamination consisted of high levels of mainly ortho ‐substituted mono‐ and dichlorobiphenyls, suggesting that the original contamination had been transformed by microbial reductive dechlorination. These sediments lost 0.07 to 1.7% of their total PCB content to the air during a 24‐h drying cycle. Sediments with varying amounts of overlying water (40 g of sediment with 25‐100 ml of water) lost significantly less PCB to the air within the first few cycles than native sediments with no overlying water. Losses due to PCB volatilization were well correlated to sediment PCB concentration and water loss but not to drying temperatures (4–43°C) within 24‐h drying cycles. The PCB congeners (mostly ortho ‐substituted mono‐, di‐, and trichlorobiphenyls) representing >90% of those volatilized within the first 24 h of drying were those produced in the sediment samples as a result of microbial reductive dechlorination of the original Aroclor 1248 contamination. The presence of these congeners in volatilized air samples was positively confirmed by gas chromatography‐mass spectrometry with Fourier transform infrared detection (FTIR). These results strongly suggest that significant amounts of mono‐, di‐, and trichlorobiphenyls may be volatilized from Aroclor 1248‐contaminated sediments at ambient environmental conditions and that this PCB volatilization may be enhanced by microbial reductive dechlorination.