湘江中上游沉积物中重金属污染及潜在生态危害变化趋势研究

Research on the Sediment Heavy Metal Pollution and Latent Ecological Hazard Change Tendency in Middle and Upper Reaches of Xiangjiang River

本文选取2000—2009年湘江中上游7个河断面140个沉积物样本,对河段沉积物样品中Cu、Zn、Mn、As、Hg、Cd、Cr和Pb 8种重金属元素的污染状况进行了研究,并采用Sperarmen秩相关系数和底质重金属潜在生态危害指数法对其生态危害变化趋势进行评价,结果表明:该河段沉积物中主要重金属污染因子为Hg、Cd和As,污染主要集中在上游松柏断面;10年间,重金属污染及其潜在生态危害逐渐向下游迁移,位于上游的松柏、新塘铺和黄茶岭3个断面呈下降趋势,而位于下游的枣子坪、站门前和熬洲3个断面呈上升趋势。

Taking 140 sediment samples from 7 river cross sections in the middle and upper reaches of Xiangjiang River from 2000-2009,this paper studies the pollution of 8 heavy metals of Cu,Zn,Mn,As,Hg,Cd,Cr and Pb in these samples and assesses its latent ecological hazard tendency.The results show that the major heavy metal pollution factors are Hg,Cd and As and the pollution is concentrated on the upper reaches.In the past years,the heavy metal pollution and its latent ecological hazard have gradually shifted to the lower reaches,for 3 cross sections in the upper reaches show the declining tendency while 3 cross sections in the lower reaches indicate the escalation.