[Screening and Control Measures for New Priority Pollutants in Surface Water of Tianjin]

Emerging pollutants are frequently detected in surface water, threatening the regional aquatic ecosystem and human health. Due to their complex types and large differences in risk and toxicity, research based on the comprehensive assessment of the pollution characteristics to determine the new priority pollutants remains incomplete. This study established a multi-criterion scoring method targeting 41 emerging pollutants with the goal of protecting aquatic organisms and human health, using five key indicators including environmental exposure level, persistence, bioaccumulation, ecological risk, and health risk of pollutants. The emerging pollutants were screened and identified in the surface water of Tianjin. The priority levels of different congeners were divided, and the ecological and health risks of pollutants in the priority control list were evaluated. The results showed that 41 emerging pollutants were generally detected in the study area. The average concentration of sulfonamide antibiotics (SAs) and other drugs (Others) were the largest, with 200.04 ng·L^-1 and 176.30 ng·L^-1, respectively, followed by perfluorinated compounds (PFASs, 57.98 ng·L^-1). In terms of pollutant categories, high-priority emerging pollutants were dominated by PFASs, accounting for 50%. Medium-priority emerging pollutants were still dominated by PFASs (26.32%), but the proportion was lower. Low-priority emerging pollutants were dominated by SAs, accounting for 31.25%. Perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), carbamazepine (CBZ), caffeine (CAF), perfluorohexyl sulfonic acid (PFHxA), and clarithromycin (CLA) were defined as a priority control list. Compared with other pollutants, PFOS and PFOA had higher scores in persistence, bioaccumulation, and health risk, whereas CBZ and CAF had higher scores in ecological risk. The average risk quotient (RQ) of CAF was 4.8, which indicated a relatively high ecological risk. Health risk indicated that the potential risk caused by PFOA (average hazard quotient was 0.018) cannot be ignored. For the priority control list, because of the high removal rate of CAF in sewage treatment plants, the construction of a pipe network and riverside belt with high vegetation coverage should be strengthened to reduce the impact of untreated sewage discharge and rainfall runoff. Pollutants with low removal rates in sewage treatment plants should be treated with combined technologies to improve the removal efficiency. In addition, industry substitution work should be accelerated to reduce emissions of PFOS, PFOA, and PFHxA.