Effect of temperature on the reductive dechlorination of 1,2,3,4-tetrachlorodibenzofuran in anaerobic PCDD/F-contaminated sediments.
The effect of temperature on the reductive dechlorination in sediments of the PCDD/F-contaminated Kymijoki River, Finland was assessed with 1,2,3,4-tetrachlorodibenzofuran (1,2,3,4-TeCDF) at various temperatures and with co-amendment of 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP) in laboratory microcosms. The dechlorination rate of 1,2,3,4-TeCDF increased with incubation temperature, with TeCDF half-lives of 2.1 y at 21°C, 3.9 y at 15°C, and 19.0 y at 4°C. Co-amendment with 2,3,4,6-TeCP reduced the TeCDF half-life to 1.8 y at 21°C. 1,2,3,4-TeCDF was dechlorinated mainly in the lateral position to 1,3,4-TrCDF and then to 1,3-DiCDF over 29 months, but incubation temperature affected the relative molar ratios of the dechlorination products. The abundance of the Dehalococcoides-like Chloroflexi community did not substantially change in microcosms over 24 months incubation at the different temperatures. The dechlorination activity of 1,2,3,4-TeCDF was significantly limited at lower temperatures, which should be considered in predicting the environmental fate of aged PCDD/Fs in sediments of the Kymijoki River.
University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland. Electronic address: sanna.kuokka@helsinki.fi.
S
S
Kuokka
University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland.
A-L
AL
Rantalainen
University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland.
M
M
Romantschuk
University of Helsinki, Dept. of Environmental Sciences, Lahti, Finland; Rutgers University, Dept. of Biochemistry and Microbiology, New Brunswick, NJ, USA.
M M
MM
Häggblom
D000693:Anaerobiosis; D001572:Benzofurans / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002713:Chlorine / Q000737:chemistry; D041862:Chloroflexi / Q000235:genetics / Q000378:metabolism*; D002733:Chlorophenols / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D019015:Geologic Sediments / Q000382:microbiology*; D010084:Oxidation-Reduction; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D013696:Temperature; D014874:Water Pollutants, Chemical / Q000378:metabolism*
D001572:Benzofurans; D002733:Chlorophenols; D004269:DNA, Bacterial; D000072317:Polychlorinated Dibenzodioxins; D012336:RNA, Ribosomal, 16S; D014874:Water Pollutants, Chemical; C031487:2,3,4,6-tetrachlorophenol; D002713:Chlorine; C508215:1,2,3,4-tetrachlorodibenzofuran
PCDD/F; Reductive dechlorination; Sediment; Temperature