Atmospheric aggravation potential of a wastewater treatment plant concerning organochlorine pesticides, polychlorinated biphenyls, and polybrominated diphenyl ether emissions.

The pollution potential of a municipal wastewater treatment plant (WWTP) in Bursa, Türkiye, in terms of organochlorine pesticides (ΣOCPs), polychlorinated biphenyls (ΣPCBs), and polybrominated diphenyl ethers (ΣPBDEs), was investigated in air samples. Concentrations were determined using polyurethane foam disk samplers at key processes, such as the aeration tank (AT) and settling chamber (SC) of the WWTP and the background area (BA) at an urban site. Atmospheric concentration levels of PBDEs at the SC are 1.3 times higher than at the AT site. PCBs concentration levels are listed as SC > BA > AT from high to low. The highest OCPs concentration levels were detected at the BA site while the lowest concentration levels were obtained for the SC site. Compared to organochlorine pollutants (PCBs and OCPs), PBDEs levels were higher by two orders of magnitude ranging from 0.2 to 54.3 ng/g. While the presence of OCPs was not significant, an unusual abundance of mirex was observed. HCB, HCHs (excluding β-HCH), and p,p'-DDE resulting mainly from the settling tank indicate enhanced mass transfer from wastewater to air. Regarding PCBs, the level and detection frequency of dioxin-like PCBs (118, 123) in the aeration tank and the settling chamber were remarkable. The upper levels of PBDEs congeners 17, 85, 138, 153, and 154 resulting from the settling tank suggest an enhanced mass transfer from water to air as the source medium. Although the primary fate of trace organics in WWTPs is expected to be sorption to sludge, the present study has shown that WWTPs can be a non-negligible source of local atmospheric PCB and PBDE pollution. However, this study provides a snapshot of the levels of persistent organic pollutants and emissions, and there is no doubt that more detailed and long-term studies are needed.