石煤尾矿区土壤重金属污染风险评价

Potential ecological risk assessment of soil heavy metals in a stone-like coal tailing using TCLP and Hakanson method

以某石煤尾矿库及周边农田表层土壤为研究对象,采用TCLP法对土壤中Pb,Cd,Cu,Zn的生物可利用态风险进行评价,并运用Hakanson潜在生态风险指数法综合评价其潜在生态危害程度。结果表明:研究区土壤中Pb,Cd,Cu,Zn的平均质量分数均高于陕西省土壤元素背景值标准;TCLP法提取的重金属质量分数与国际标准值相比较,除Cu和Zn之外,Cd和Pb元素均超标;相关性分析表明,研究区土壤中除Pb和Cu之间呈显著正相关关系,其余元素两两之间呈极显著正相关关系;潜在生态风险评价结果表明,研究区土壤中Pb,Cd,Cu,Zn潜在生态风险综合指数均值为491.71,属强生态危害程度,Cd元素是构成潜在生态风险的主要因子。石煤尾矿库已对周围土壤造成重金属污染危害。

The ecological risks of soil heavy metals,including Pb,Cd,Cu and Zn in farmland surface soil around a stone-like coal tailing,were evaluated with TCLP method and Hakanson potential ecological risk index method.The results show that the average contents of Pb,Cd,Cu and Zn are higher than the soil element background values of Shaanxi province.Comparing the extraction of TCLP with the international standard,Cd and Pb are higher than the international standard except Cu and Zn.Correlation analysis shows that the soil heavy metals are very significant positive correlation in the study area,but the relationship between Pb and Cu is significant positive correlation.The average index of Hakanson potential ecological risk is 491.71,which belongs to high ecological hazard,Cd is the main risk factor.The soil around the stone-like tailing has been polluted seriously.