TY - JOUR TI - Fate and transport of polychlorinated biphenyls in the air, water, and sewers of the Delaware River Basin DO - https://doi.org/doi:10.7282/T3S1813C PY - 2013 AB - Passive air samplers were deployed at 45 sites across the Delaware River Basin to evaluate the spatial distribution of atmospheric polychlorinated biphenyls (PCBs). This study revealed strong spatial gradients in ΣPCB concentrations, a significant urban fractionation effect, and a distinct congener pattern arising from the area around Swarthmore, PA. Five factors were resolved by positive matrix factorization (PMF) analysis with three of them being interpreted as volatilized or weathered Aroclors. The other two factors were strongly correlated to the congener profiles observed at the Swarthmore site on a building roof and an urban site near rail yards, respectively. These findings suggest that volatilization of Aroclors from building materials and spray on rail yards could represent significant sources of ambient atmospheric PCB concentrations. In the passive air sampling, the concentrations of a non-Aroclor congener, PCB 11, were detected with small spatial variation in the airshed of the Delaware River Basin. PCB 11 was measured from non-detect to 79 ng g-1 in consumer products containing pigments and dyes. The leaching potential of PCB 11 from these materials was confirmed by experimental tests. The inputs of PCB 11 to the Delaware River Basin were estimated between 0.025 and 42 kg y-1, while the outflows were between 8.4 and 260 kg y-1. These mass flows indicate that PCB 11 is present in pigments at levels close to or even exceeding the federal limits and/or that the degradation of these pigments releases PCB 11 into the basin. Reductive dechlorination of PCBs was investigated in anaerobic microcosms of sewer sediments amended with Aroclor 1260 under methanogenic conditions. Spatial heterogeneity of the sediments resulted in differences in the extent of dechlorination activity. The most active microcosm showed dechlorination evidence after 35 days of incubation with significant accumulation of documented dechlorination products and molar dechlorination product ratio (MDPR). Total chlorines per biphenyl decreased by up to 10% with short or no lag time. This suggests that rapid dechlorination is at least possible to account for the dechlorination products comprising 10~30% of the total PCBs, which were found in many of the sewer systems in the Delaware River Basin. KW - Environmental Sciences KW - Polychlorinated biphenyls KW - Air--Pollution--Delaware River Watershed (N.Y.-Del. and N.J.) KW - Water--Pollution--Delaware River Watershed (N.Y.-Del. and N.J.) LA - eng ER -