Occurrences, removal effects and ecological risks of multiple endocrine disruptors in typical wastewater treatment plant of the Yangtze River Delta

In 2022, China officially launched the New Pollutant Control Action Plan, with environmental endocrine-disrupting chemicals (EDCs) designated as priority regulated substances. Wastewater treatment plants (WWTPs) are important point sources of EDCs in aquatic environments, while conventional treatment processes often exhibit limited removal efficiency for these contaminants. Therefore, it is urgent to systematically evaluate the removal efficiency and ecological risks of EDCs in WWTPs to guide technological optimization and policy formulation. In this study, the occurrence, distribution, sources, removal characteristics, and ecological risks of multiple classes of EDCs were investigated in 14 WWTPs across the Yangtze River Delta region. Among the 53 target EDCs, 36 compounds were detected in more than 60% of all samples, including 7 bisphenol A (BPA) and its analogues, 4 parabens (PBs), 3 benzophenones (BPs), 4 nonylphenols (NPs), 12 phenols and their derivatives (Phs), 5 phthalate esters, and triclosan. Source identification revealed that Phs (e.g., alkyl-substituted phenols and chlorophenols) in WWTP influent mainly originated from industrial wastewater discharge, whereas PBs and BPs were primarily associated with domestic sewage. The typical A 2 /O + MBR + disinfection combined process achieved efficient removal of most EDCs, especially BPA, and the biological treatment unit was identified as the core section for pollutant removal. Although the overall ecological risk of EDCs in effluent remained low based on the risk quotient assessment, bisphenol S, 4-nonylphenol, dibutyl phthalate, and BPA posed moderate ecological risks. According to the ToxPi ranking, these EDCs were recognized as priority pollutants, and their inclusion into the regional priority monitoring list is thus recommended.