治理后的太湖无锡区域底质中重金属污染现状及生态风险评价

Current Status of Heavy Metal Pollution and Ecological Risk Assessment in Sediment of Lake Taihu in Wuxi Area after Pollution Treatment

以2005年以后太湖无锡区域底质为研究对象,分析了太湖底泥中重金属的含量分布及富集状况,采用地积累指数法和潜在生态危害指数法对重金属的生态危害进行评价。结果表明:太湖无锡区域底质受重金属轻度污染,含量高于全国水系沉积物平均值;地积累指数法显示太湖无锡区域底质中重金属污染排序为Cu=As>Pb>Zn>Cr>Cd>Hg;金属对太湖无锡区域底质构成的潜在生态危害由强到弱为Hg>Cu>As>Cd>Pb>Cr>Zn;从区域上看,2种评价方法均表明底质中重金属危害程度为宜兴沿岸区>梅梁湖>五里湖>贡湖无锡水域。

This article concentrates on the sediments of Lake Taihu in Wuxi Area after 2005 as the research object, analysis the distribution of heavy metal in lake mud and enrichment status, the index of geoaceumulation and potential ecological risk was used to evaluate the pollution level of heavy metals in sediments. The restdt indicated that the sediments of lake Taihu in Wuxi area were shghtly polluted by heavy metals, and the content was higher than the national average. The index of geoaceumuation showed that the order of heavy metal pollution in sediments of Lake Taihu in Wuxi area was： Cu = As 〉 Pb 〉 Zn 〉 Cr 〉 Cd 〉 Hg; the order of the potential ecological risk for sediment of Lake Taihu in Wuxi district was： Hg 〉 Cu 〉 As 〉 Cd 〉 Pb 〉 Cr 〉 Zn; two kinds of evaluation methods base on the area distribution which showed the rank of heavy metal damaged level of sediments of Lake Taihu in Wuxi was： Yinxin coastwise 〉 Meiliang Lake 〉 Wuli Lake 〉 Gong Lake in Wuxi Area.