ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReductive Dechlorination of Polychlorinated Biphenyls in St. Lawrence River Sediments and Variations in Dechlorination CharacteristicsRoger C. Sokol, O-Seob. Kwon, Charlotte M. Bethoney, and G.-Yull. RheeCite this: Environ. Sci. Technol. 1994, 28, 12, 2054–2064Publication Date (Print):November 1, 1994Publication History Published online1 May 2002Published inissue 1 November 1994https://pubs.acs.org/doi/10.1021/es00061a013https://doi.org/10.1021/es00061a013research-articleACS PublicationsRequest reuse permissionsArticle Views200Altmetric-Citations83LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDechlorination of polychlorinated biphenyls by Hudson River sediment organisms: specificity to the chlorination pattern of congenersG. Yull Rhee, Roger C. Sokol, Charlotte M. Bethoney, and Brian BushCite this: Environ. Sci. Technol. 1993, 27, 6, 1190–1192Publication Date (Print):June 1, 1993Publication History Published online1 May 2002Published inissue 1 June 1993https://doi.org/10.1021/es00043a020Request reuse permissionsArticle Views98Altmetric-Citations46LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (443 KB) Get e-Alertsclose Get e-Alerts
Reductive dechlorination of polychlorinated biphenyls primarily removes chlorines (Cls) from the meta and para positions although ortho dechlorination has also been reported. This preferential removal is determined by the pattern of Cl substitution. Thus, the final products may not only be orth-substituted congeners. In fact, certain congeners such as 2,4{prime}-, 2,5,2{prime}-, 2,4,4{prime}, 2,4,2{prime},5{prime}- and 2,4,2{prime}4{prime}-chlorobiphenyls accumulated at high concentrations in both the laboratory and natural sediments in the Hudson and St. Lawrence Rivers. Many of these accumulating congeners are known to be neurotoxic by reducing cellular dopamine content. Therefore, although in-situ dechlorination may reduce the overall degree of chlorination, it is important to consider the health implications of accumulating products. Dechlorination competence varies with sediment microorganisms from different sites, resulting in the accumulation of dissimilar products. Microorganisms from the General Motors site in the St. Lawrence River removed a higher proportion of para Cls relative to meta whereas those organisms at the Reynolds and ALCOA sites removed a higher proportion of meta Cls. Sediment amendments with H{sub 2} or biphenyl also resulted in the accumulation of different products. These results suggest that it may be possible to alter the final products through artificial manipulations. The authors have identified several conditionsmore » which are critical for dechlorination.« less
Abstract The effect of electron acceptors and biphenyl on reductive dechlorination was investigated using the commercial polychlorinated biphenyl mixture Aroclor 1242 and sediment microorganisms from the Hudson River. Polychlorinated biphenyl- (PCB-) free sediments spiked with the Aroclor at 700 μg/g and anaerobically incubated for six months, with and without biphenyl enrichment, showed that dechlorination was most advanced with CO2 without biphenyl enrichment. A small amount of methane was detected. However, methane production per se was not essential for dechlorination, because addition of the inhibitor of methane production, 2-bromoethane sulfonate, did not affect dechlorination. On the other hand, dechlorination was inhibited partly by sulfate and completely by nitrate. Biphenyl enrichment initially inhibited dechlorination under both methanogenic and sulfidogenic conditions.
The present study has investigated a correlation between the kinetics of polychlorinated biphenyl (PCB) dechlorination and the growth of dechlorinating microbial populations. Microorganisms were eluted from Aroclor 1248-contaminated St. Lawrence River (NY, USA) sediments and inoculated into clean sediments spiked with Aroclor 1248 at 10 concentrations ranging from 0 to 3.12 micromol/g sediment (0-900 ppm). The time course of PCB dechlorination and population growth were concurrently determined by congener-specific analysis and the most probable number technique, respectively. The specific growth rate was a saturation function of PCB concentrations above the threshold concentration (0.14 micromol/g sediment, or 40 ppm), below which no dechlorination or growth of dechlorinations were observed. The maximum growth rate was 0.20/d with a half-saturation constant of 1.23 micromol/g sediment. The yield of dechlorinating microorganisms showed a peak at 0.70 micromol/g sediment (200 ppm), with a value of 10.3 x 10(12) cells/mol Cl removed, and decreased below and above this concentration. The dechlorination rate (micromol Cl removed/g sediment/d) was a linear function of Aroclor concentration. Both the log of this rate and the maximum level of dechlorination were significantly correlated with growth rate. The biomass-normalized dechlorination rate (micromol Cl removed/g sediment/cell/d) was first order because of the exponential manner of the population growth. The first-order rate constant was a saturation function of Aroclor concentrations, with a maximum of 0.24/d (a half-life of 2.9 d) and a half-saturation constant of 1.18 micromol/g sediment, which are similar to the constants for growth. These results indicate that the dechlorination rate is tightly linked to the population growth of dechlorinating microorganisms.
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