Prevalence and Prioritization of Phenolic and Organophosphate Ester Endocrine Disruptors and Their Transformation Products in Municipal Wastewater Treatment Plants

This study presents the first investigation of the occurrence, removal efficiencies, and ecological risks of 62 endocrine disrupting chemicals (EDCs), including parabens (PBs) and their halogenated derivatives, triclosan (TCS), bisphenols (BPs) and their halogenated derivatives, alkylphenols (APs), organophosphate triesters (tri-OPEs), and organophosphate diesters (di-OPEs), in 14 municipal wastewater treatment plants (WWTPs) within China’s Greater Bay Area. We developed a dansyl chloride derivatization method for detecting 34 phenolic EDCs, achieving detection limits as low as 0.005–2 ng/L. Bisphenol S, methylparaben, tris(1-chloro-2-propyl) phosphate, di-n-butyl phosphate, 4-nonylphenol, and TCS were prevalent in both influents and final effluents toward each EDC category. Most WWTPs achieved over 80% removal for BPs and PBs, likely due to biological oxidation in secondary treatment. However, the removal of chlorinated PBs, chlorinated BPs, APs, tri- and di-OPEs was generally insufficient. Especially for methyl 3,5-dichloro-4-hydroxybenzoate and 3-chlorobisphenol A, their detection frequencies and concentrations were significantly higher in final effluents compared to influents (p < 0.05). Risk assessment and toxicological priority index revealed 4-tert-octylphenol and tris(2-chloroethyl) phosphate as priority pollutants due to their potential high ecological risks. These findings underscore the urgent need to enhance wastewater treatment technologies, with a focus on removing priority pollutants to ensure the long-term sustainability of aquatic ecosystems.