洞庭湖沉积物重金属环境地球化学  

Environmental geochemistry of heavy metals in sediments of Dongting Lake

作　　者：姚志刚[1,2] 鲍征宇[3,4] 高璞[1] 

机构地区：[1]西安石油大学油气资源学院 [2]中国地质大学地质过程与矿产资源国家重点实验室,湖北武汉430074 [3]中国地质大学地质过程与矿产资源国家重点实验室 [4]中国地质大学地球科学学院,湖北武汉430074

出　　处：《地球化学》2006年第6期629-638,共10页Geochimica

基　　金：中国地质调查局地质调查实施项目(200314200021)

摘　　要：对洞庭湖沉积物样进行了Cu、Pb、Zn、Cd、Cr、Ni、As和Hg等8种元素含量分析。结果显示,洞庭湖沉积物中重金属污染物主要是Cd和Hg,其次是Pb、Zn、As和Cu;Cd平均含量达到2.7mg/kg,是国家土壤环境质量三级标准(1.0mg/kg)的近3倍;Cu、Pb、Zn、As和Hg平均含量分别为51.3mg/kg、52.8mg/kg、140mg/kg、22.5mg/kg和0.22mg/kg,均超过国家土壤环境质量一级标准。运用地累积指数法对其污染程度进行了评价,认为重金属污染最严重的湖区是东洞庭湖的鹿角至城陵矶湖区(段),污染物可能主要来源于湘江流域;各子湖区(段)重金属综合污染状况评价结果是:东洞庭湖>大通湖>横岭湖>万子湖>西洞庭湖>采桑湖。入湖各河口区沉积物重金属含量与历史资料的对比表明,8种重金属含量均有较高程度的富集,反映近年来洞庭湖流域内重金属污染有增加的趋势。Contents of copper, lead, zinc, cadmium, chromium, nickel, arsenic and mercury in the sediments of Dongting Lake were quantitatively analyzed. The results show that Cd and Hg are the main heavy metal pollutions, followed by Pb, Zn, As and Cu. Especially, the average content of Cd in the sediments of the whole lake reaches 2. 7 mg/kg, which exceeds the standard of class Ⅲ of environmental quality standard （1.0 mg/kg） for Soils in China. The average contents of Cu, Pb, Zn, As and Hg are 51.3 mg/kg, 52. 8 mg/kg, 140 mg/kg, 22. 5 rag/ kg and 0.22 mg/kg, respectively, which exceed the standard of class Ⅰ of environmental quality standard for soils in China. The degree of pollution is estimated by the geoaccumulation index, which indicates that the most seriously polluted section of the sediments is the section from Lujiao to Chenglingji within East Dongting Lake, the pollution sources of which mainly result from the Xiangjiang River drainage area; the decreasing order of the degree of heavy metal integrative pollution is as follows： East Dongting Lake 〉 Datong Lake 〉 Hengling Lake 〉 Wanzi Lake 〉 West Dongting Lake 〉 Caisang Lake. Comparing the contents of sediments in river mouths where tributaries flow into Dongting Lake with the historical data, the average contents of the eight kinds of heavy metals are considerably increased, which reflects the enhanced trend of heavy metal contamination in recent years.

关 键 词：沉积物 地累积指数 重金属污染 洞庭湖 

分 类 号：P595[天文地球—地球化学] X142[天文地球—地质学]