[Priority Control Screening of Organic Micropollutants in the Water Body of the Lower Reaches of the Yangtze River from Wuhu to Nanjing].

Abstract

The types and emissions of chemicals are constantly increasing， posing a huge threat to aquatic ecosystems. Given the complexity and large quantity of pollutants， it is difficult to achieve comprehensive monitoring and control. Therefore， screening out the priority pollutants that pose a significant threat to aquatic ecosystems is the key to formulating pollution control measures. The section of the Yangtze River's main stream from Wuhu to Nanjing is a core component of the Yangtze River Economic Belt. The water pollution problems caused by economic growth may lead to an increase in organic micropollutants （OMPs） in the water bodies， thereby threatening the ecological security. This study detected 197 OMPs in the mainstream of the Yangtze River from Wuhu to Nanjing， with 150 contaminants identified. Priority screening was conducted based on hazard effects， occurrence levels， and risk prioritization. The hazard potential （HP） was determined based on the environmental persistence， bioaccumulation， and ecotoxicity of pollutants. The exposure potential （EP） was determined by the median concentration and detection rate of pollutants， and the priority index （PI） was calculated. The results showed that polybrominated diphenyl ethers （PBDEs） and polychlorinated biphenyls （PCBs） had high HP values， while sweeteners （SAs） had low HP values. SAs exhibited the highest EP values， whereas PBDEs had the lowest EP values. Risk assessment indicated that 34 pollutants posed a threat to the ecosystem. Based on the PI index， a list of 11 high-priority pollutants was generated. Among the high-priority pollutants， PFASs accounted for as high as 54.5%. PFASs mainly originated from industrial emissions. For future ecological environment monitoring and regulation in the Wuhu-Nanjing section of the Yangtze River mainstream， special attention should be paid to PFOA， PFNA， PFOS， 10∶2 FTCA， HFPO-TA， 8∶2 FTCA， BDE194， BDE209， BDE206， DEHP， and DBDPE. Pollutants with medium priority also require attention. It is suggested that stricter supervision and treatment measures should be implemented for the wastewater from fluorine chemical， electroplating， and textile enterprises along the river， in order to control the emission of PFASs.