重金属污染沉积物质量评价研究—以太湖为例

以太湖的表层沉积物为研究对象,运用相平衡分配法(EqP)探讨了沉积物中4种重金属(Cu, Pb, Zn, Cd)的沉积物质量基准(CSQC)值;根据美国国家环境保护局(US EPA)基于水生生物对重金属的最终慢性毒理水平的淡水水质基准,制定了太湖4种重金属(Cu, Pb, Zn,和Cd)的沉积物质量基准值分别为145.2,308.72,293.01,0.46mg/kg.以此CSQC为参比值,参考潜在生态危害指数法对各元素赋予不同的权重值,运用综合污染指数法对太湖沉积物重金属的环境质量进行评价,结果显示,2010年8~9月太湖沉积物质量基本为良.这一结果与沉积物重金属总量分析结果一致.

Quality assessment technology of sediment polluted by heavy metals of the Taihu Lake

The equilibrium partitioning (EqP) approach was used to preliminarily discuss the sediment quality criteria (SQC) recommended values of four heavy metals-cadmium (Cd) , copper (Cu) , lead (Pb) , and zinc (Zn) for surface sediments from Taihu Lake. The SQCs for the heavy metals were calculated using the US EPA fresh quality criteria, which were based on aquatic toxicity of the final chronic level of heavy metals. The calculated SQCs of Cu, Pb, Zn and Cd of the Taihu Lake were 145.2, 308.72, 293.01 and 0.46mg/kg. Taking this SQC as reference value, endowing these elements with different weights by referring to the potential ecological risk index approach and using complex pollution indices method, a new approach of quality assessment on heavy metals in surface sediments was developed, which was also applied to evaluate environmental quality of heavy metals in sediment of the Taihu Lake. Sediment quality of the whole Taihu Lake were primarily in “good” level based on the sample analysis (2010-8,9). The results were coherence with the analysis of total heavy metals.