太湖保护水生生物2,4-二氯苯酚基准研究

Derivation of water quality criteria of 2,4-dichlorophenol for protection of aquatic life in Tai Lake

2,4-二氯苯酚(2,4-DCP)被纳入我国优先污染物名单,同时也是水环境中最常见的氯酚类化合物的一种,而太湖作为中国最大和污染最严重的淡水湖之一,需要针对2,4-DCP进行区域水质基准研究为太湖水质改善提供基础数据.通过太湖8种本土生物的急性毒性试验并两步外推法补充了相应的慢性毒性数据.结合文献数据建立该化合物的太湖水生生物毒性和pH数据库,依据协方差分析得到太湖急慢性双基准(CMC和CCC)的pH方程式.当pH=7.8时,通过传统物种敏感度分布法得到太湖CMC和CCC,分别为610.42μg·L-1和9.80μg·L-1.此外,水质基准主要是基于实验室能培养、繁育、实验的水生生物的毒性数据推导而来的,和太湖实际生物区系比例难以一致,因此结合太湖生物区系和水质特征,利用物种权重敏感度分布法得到太湖CMC和CCC值分别为584.43μg·L-1和6.83μg·L-1.本研究对科学管理区域水环境中污染物,实现水化学、生态完整性具有一定支撑,对我国2,4-DCP区域水质标准的制定有一定的参考价值.

2,4-Dichlorophenol is a priority pollutant and one of the most abundant chlorophenols in the aquatic biota of China.It is necessary to conduct a regional water quality criteria study on 2,4-DCP to provide basic data for water quality improvement in Tai Lake,one of the largest and most polluted freshwater lakes in China.To supplement the toxicity data,eight native species were selected to perform acute toxicity tests and further extrapolate chronic toxicity data based on acute threshold concentrations during each duration of acute exposure.The toxicity and pH database of 2,4-dichlorophenol for aquatic organisms in Tai Lake was established based on literature,and the pH-dependent water quality criteria(CMC and CCC)was deduced by covariance analysis.At pH 7.8,CMC and CCC of Tai Lake based species sensitivity distribution were 610.42 and 9.80μg·L-1,respectively.With the toxicity data of aquatic organisms that can be cultured and bred in the laboratory,which was difficult to be consistent with the proportion of the actual regional species of Tai Lake.Therefore,CMC and CCC of Tai Lake were 584.43 and 6.83μg·L-1,respectively,using the weighted species sensitivity distribution in combination with water characteristics and taxonomic groups distribution in Tai Lake.This study supports the scientific management of pollutants in regional water environment and the realization of water chemistry and ecological integrity.It also provides references for the establishment of water quality standards of 2,4-DCP in China.