太湖流域3种氯酚类化合物水质基准的探讨

Discussion of Quality Criteria for Three Chlorophenols in Taihu Lake

按照美国地面水水质基准制定的程序和规范,筛选了太湖流域广泛存在的水生生物物种并收集了相应的基础毒性数据,探讨了五氯酚(PCP)、2,4-二氯酚(2,4-DCP)和2,4,6-三氯酚(2,4,6-TCP)在我国太湖地区的水生态基准的定值.同时采用蒙特卡罗构建物种敏感度分布(SSD)曲线和生态毒理模型方法预测了3种氯酚类化合物对太湖水生生物的急性基准浓度(CMC)和慢性基准浓度(CCC).结果表明,基于EPA规范方法和急慢性毒性比率得到的PCP、2,4-DCP和2,4,6-TCP3种氯酚类化合物的CMC值分别为25、908和594μg·L-1,CCC值分别为12、176和162μg·L-1;基于SSD曲线得到的CMC值分别为25、818和648μg·L-1,CCC值分别为6、75和198μg·L-1;基于生态毒理模型得到的CCC值分别为4、15和67μg·L-1,显示出3种方法得到的氯酚类化合物的CMC或CCC在同一个数量级上,但在数值上由生态毒理模型得出的CCC要小于其它两种方法,并且除PCP的急慢性基准值与美国EPA推出的水生态基准值相近外,其它两种氯酚类化合物的急慢性基准值均低于美国EPA推出的急慢性基准值.研究结果希望能为我国水质基准的制定提供一些有用的线索.

According to the methods and procedures of surface water quality criteria established by U.S. EPA, the aquatic species existing widely in the Taihu Lake basin were selected, and their toxicity data were collected. The aquatic quality criteria of pentachlorophenol （PCP）, 2,4-dichlorophenol （2, 4-DCP）and 2,4,6-trichlorophenol （2,4,6-TCP）in the Taihu Lake basin were discussed. At the same time, species sensitivity distribution curves（ SSD）based on Monte Carlo model and eco-toxicological models were employed to derive criteria maximum concentration（CMC）and criteria continuous concentration （CCC）of three chlorophenols for protection of aquatic life in the Taihu Lake basin. Results showed that the CMC of PCP, 2,4-DCP and 2,4,6-TCP based on the EPA methods and acute chronic ratio were 25, 908, 59μg·L^-1, and the CCC were 12, 176 and 162μg·L^-1, respectively. Based on the SSD, the CMC and CCC of three chlorophenols were 25, 818, 648μg·L^-1, and 6, 75, 198μg·L^-1, respectively. Based on the eco-toxicological models, the CCC were 4, 15 and 67μg·L^-1, respectively. As we can see that CMC or CCC obtained by three methods were in the same order of magnitude, but CCC in numerical value obtained by eco-toxicological model was less than other two methods. Furthermore, the acute and chronic criteria values of three chlorophenols besides PCP were all lower than the corresponding criteria values launched by the U.S. EPA. The results of this study wish to provide useful clues for deriving national or local water quality criteria of different chemicals for protecting aquatic biota in China.