1 research outputs found
Evidence for Dechlorination of Polychlorinated Biphenyls and Polychlorinated Dibenzo-<i>p</i>-Dioxins and -Furans in Wastewater Collection Systems in the New York Metropolitan Area
Polychlorinated biphenyls (PCBs) and polychlorinated
dibenzo-<i>p</i>-dioxins and dibenzofurans (PCDD/Fs) are
persistent organic
pollutants targeted by the Stockholm Convention. Both contain aromatic
chlorines and are subject to microbial dechlorination. Dechlorination
of PCBs in sewers in the Delaware River basin was recently reported.
In this work, two data sets on concentrations of PCBs and PCBs+PCDD/Fs
in wastewater treatment plant influents and effluents were analyzed
to look for evidence that these compounds undergo dechlorination in
the sewers of the New York/New Jersey Harbor area. The two data sets
come from the Contamination Assessment and Reduction Project (CARP)
and were analyzed via Positive Matrix Factorization (PMF). Analysis
of the data set containing only PCB concentrations suggests that PCBs
are dechlorinated in the sewers of the NY/NJ Harbor via the same pathways
observed in the sewers of the Delaware River basin and that advanced
dechlorination of PCB mixtures is more likely to occur in combined
sewers vs separate sanitary sewers. When the combined data set of
PCBs+PCDD/Fs was analyzed, the factor containing PCB dechlorination
products also contained high proportions of 1,2,3,4,6,7,8-heptachlorodibenzo-<i>p</i>-dioxin (HpCDD), a known product of the dechlorination
of octachlorodibenzo-<i>p</i>-dioxin (OCDD), and other known
dechlorination products of PCDD/Fs. Despite being the most abundant
PCDD/F congener in all of the samples in the database, OCDD was a
minor component in the dechlorination factor. This provides the first
evidence that PCDD/Fs may be dechlorinated in sewers