我国淡水环境中卤乙酸类消毒副产物的预测无效应浓度研究

新型冠状病毒肺炎（COVID-19，简称“新冠肺炎”）疫情期间，消毒剂超量使用，导致大量DBPs（disinfection by-products，消毒副产物）进入自然水体，可能对水生态环境产生不良影响.以5种HAAs（卤乙酸类）消毒副产物（一氯乙酸、二氯乙酸、三氯乙酸、一溴乙酸和二溴乙酸）为研究目标，基于筛选的本土水生生物的毒性数据，采用欧盟《风险评价技术指导文件》中的评估系数法和平衡分配法分别推导了5种HAAs在水体和沉积物两种介质中的PNEC（预测无效应浓度）值.结果表明:5种HAAs对水生生物的急、慢性毒性大小顺序均为一溴乙酸>一氯乙酸>二氯乙酸>三氯乙酸>二溴乙酸；5种HAAs（一氯乙酸、二氯乙酸、三氯乙酸、一溴乙酸和二溴乙酸）的PNEC_w（水体的预测无效应浓度）分别为0.025、0.030、0.060、0.016和1.956 mg/L，PNEC_s（沉积物的预测无效应浓度）分别为0.021、0.026、0.057、0.013和1.679 mg/kg（以湿质量计）.研究显示，污水处理厂出水中排放的DBPs对水生态环境可能造成潜在的风险和危害，应加强对污水处理厂出水中5种HAAs的监测和去除，从而减少排入到自然水体中的HAAs含量. 

Predicted Non-Effect Concentrations for Disinfection By-Products of Haloacetic Acids (HAAs) in Freshwater Environment in China

During the COVID-19, excessive use of disinfectants led to a large amount of disinfection by-products (DBPs) entering natural waters, which could have an adverse effect on the freshwater eco-environment. Five kinds of haloacetic acids (HAAs), including monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid, and dibromoacetic acid, were studied. According to the EU Technical Guidance Document on Risk Assessment, the values of PNEC of 5 HAAs were derived in the water and sediment with the toxicity data of native species in China using assessment factors and equilibrium method, respectively. The results show that the acute and chronic toxicity of the 5 HAAs to aquatic organism were both in the order of monobromoacetic acid > monochloroacetic acid > dichloroacetic acid > trichloroacetic acid > dibromoacetic acid. The PNEC values of five HAAs for water (PNEC_w) were 0.025, 0.030, 0.060, 0.016 and 1.956 mg/L, respectively; for sediment (PNEC_s) are 0.021, 0.026, 0.057, 0.013 and 1.679 mg/kg (by wet weigh), respectively. This research shows that the DBPs in the effluents of wastewater treatment plants may pose potential risks and harms to the aquatic environment. Therefore, the monitoring and removal of five HAAs in the effluents of the WWTPs should be improved to reduce the concentration of HAAs discharged into natural waters.