Uncovering emerging organophosphate esters in chemical parks using nontarget screening method: Near-field...

Chemical industrial parks (CIPs) are key drivers of regional development and important sources of organophosphate esters (OPEs) in the environment. However, information on the screening, occurrence, and near-field concentration changes of OPEs in CIPs, especially in parks dominated by flame-retardant manufacturing, remains limited. We conducted target, suspect, and non-target screening of OPEs in four CIPs in the Yangtze River Delta and detected 18 emerging OPEs in park waters for the first time; diethyl methyl phosphate (DEMP) was confirmed, representing the first environmental report of this compound. Across the four CIPs, Σ18 emerging OPEs ranged from 43.3 to 229,370 ng/L, with dibutyl phenyl phosphate (DBPP) and trimethyl phosphate (TMP) as major contributors. Enterprise outfalls and wastewater treatment plants (WWTP) influent were dominated by the traditional OPE - triethyl phosphate (TEP, median shares 67.4% and 59.7%), whereas WWTP effluent and the mixing point were dominated by the emerging DBPP (94.7% and 58.7%). For Σ₃₄emerging OPEs, concentrations decreased substantially from WWTP-effluent to downstream in CIP-B and CIP-C (by 98.27% and 99.97%, respectively), whereas in CIP-A the reduction was small or reversed (an 8.48% decrease from effluent to the mixing point and a 32.32% increase from effluent to downstream). A multi-domain ToxPi prioritization indicated that high-priority targets in all water samples were mainly emerging aryl OPEs, including tris(2,4-di-tert-butylphenyl) phosphate (TDTBPP), bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphate (B24DTBPPEDP), and bis(dipentylphenyl) phenyl phosphate (BDPePhPP), underscoring the need to include this class in priority management and routine surveillance. This study offers practical approaches for monitoring and managing emerging OPEs in industrial settings.