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Kinetics of polychlorinated biphenyl dechlorination by Hudson River, New York, USA, sediment microorganisms
Author(s) -
Cho YoungCheol,
Sokol Roger C.,
Rhee GYull
Publication year - 2002
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.5620210405
Subject(s) - congener , environmental chemistry , polychlorinated biphenyl , sediment , microorganism , biphenyl , reductive dechlorination , chemistry , biotransformation , ecotoxicology , biodegradation , environmental science , bacteria , biology , organic chemistry , paleontology , genetics , enzyme
The kinetics of polychlorinated biphenyl (PCB) dechlorination by Hudson River (New York, USA) sediment microorganisms were investigated using Aroclor 1242 at 10 concentrations ranging from 0 to 900 ppm (0–11.2 μmol Cl/g sediment). The time course of PCB dechlorination and population growth were determined by congener‐specific analysis and the most‐probable‐number technique, respectively, over a 44‐week incubation period. Dechlorination rate (nmol Cl removed/g sediment/d) was a linear function of PCB concentrations similar to the dechlorination of Aroclor 1248 by sediment microorganisms from the St. Lawrence River (New York, USA). However, the rate was much slower, with the linear slope being only 24% that of the St. Lawrence River. The threshold concentration below which no dechlorination occurs was (mean ± standard deviation) 1.06 ±0.18 μmol Cl/g sediment (85±14 ppm), threefold higher than that for the dechlorination of Aroclor 1248. The maximum extent of dechlorination was greater at higher Aroclor concentrations. Dechlorinating microorganisms did not show any significant growth until late in the lag phase of dechlorination, and their maximum was greater at higher initial Aroclor 1242 concentrations. Although dechlorination rates were significantly lower with the Hudson River inoculum, when normalized to the maximum number of dechlorinating organisms, they were not significantly different from those for Aroclor 1248 by St. Lawrence River microorganisms. These results further support the idea that PCB dechlorination is tightly linked to the growth of dechlorinating microorganisms.