草海湖底沉积物重金属垂直分布特征及污染状况评价

The Vertical Distribution Characteristics and Pollution Status of Heavy Metals in the Sediment of the Caohai Lake

选取贵州省威宁县草海湖底沉积物为研究对象,对Pb、Cr、Zn、Cu、As5种重金属的含量进行测定。采用单因子指数法和潜在生态风险指数法对各重金属污染状况进行分析评价,定量确定了草海湖底沉积物中主要的污染因子和潜在生态风险程度。结果表明:5种重金属中,Zn和Pb的含量均高于中国土壤环境背景值和贵州省土壤环境背景值,其中Zn含量最大,其次是Pb、Cr、Cu、As;各重金属在不同深度上有不同的变化规律;草海湖主要的重金属污染因子为Zn、Pb,湖底沉积物重金属的综合污染指数为8.88,属于中度污染,潜在生态危害程度低。

The sediment of Caohai Lake in Weining County,Guizhou Province was selected as the research object.The contents of five heavy metals,Pb,Cr,Zn,Cu and As,were determined.The single factor index method and potential ecological risk index method were used to analyze and evaluate the pollution status of heavy metals.Quantitatively determined the major pollution factors and potential ecological risk in sediment of Caohai Lake.The results showed:Zn content was the largest,followed by Pb,Cr,Cu,As in the five heavy metals,the contents of Zn and Pb were higher than the background value of soil environment in China and Guizhou Province.Different heavy metals had different distribution characteristics in different depths.The main heavy metal pollution factors were Zn and Pb in Caohai Lake.The comprehensive pollution index of heavy metals was 8.88 in sediment of Caohai Lake,which was moderate pollution.It meant potential ecological hazard degree was low.