恩施州矿山周边耕地土壤重金属污染特征及评价

Characteristics and Evaluation of Heavy Metal Pollution in Cultivated Soilaround Mines in Enshi Prefecture

对恩施州154个矿山(煤矿占比约72%)周边耕地土壤进行采样,测定了土壤中Pb、Cu、As、Cr、Cd、Zn、Hg等7种重金属的含量。采用统计分析了解重金属污染特征,利用单因子污染指数法、综合污染指数法和潜在生态风险指数法进行生态风险评价。7种重金属含量均值明显高出背景值,说明7种重金属呈现高累积状态,6种重金属为强变异,表明土壤中Pb、Cu、As、Cd、Zn、Hg可能受外界干扰比较大。煤矿Cd、Hg的单项污染指数较大,潜在生态风险危害也较高,应是重金属污染治理的重点。

Sampling the surrounding cultivated soil in 154 mines in Enshi Prefecture(coal mines account for about 72%),and the contents of seven heavy metals such as Pb,Cu,As,Cr,Cd,Zn and Hg in the soil were determined.Statistical analysis was used to understand the characteristics of heavy metal pollution,and single factor pollution index method,comprehensive pollution index method and potential ecological hazard index method were used to carry out ecological risk assessment.The average content of the seven heavy metals is obviously higher than the background value,indicating that the seven heavy metals are in a high accumulation state.The six heavy metals have strong variation,indicating that Pb,Cu,As,Cd,Zn and Hg in soil may be greatly disturbed by the outside world.The single pollution index of Cd and Hg is relatively large,and the potential ecological risks are also relatively high,which should be the focus of heavy metal pollution control.