金矿矿渣遗存点土壤重金属污染评价和来源解析

Assessment and Source Apportionment of Heavy Metal Pollution in Soil of a Gold Ore Slag Muck Historical Remains Point

以海南某金矿矿渣清理后的14件表层土壤为研究对象,分析测定Cu、Pb、Zn、Cr、Ni、Cd、As、Hg等8种重金属元素含量;采用单因子和内梅罗综合指数法、地累积指数法、潜在生态风险指数法,评价矿渣对土壤的污染程度。Spearman分析表明,Cr、Ni、Cu、Pb、Zn、Cd、As等7种重金属具有较强的相关性,来源于矿石;Hg为外源性的重金属。14个点位内梅罗指数均值均达到中重度污染水平,主要贡献因子为Hg、As、Pb、Cd等;地累积结果显示所有点位重金属地质累积指数的均值为3.2,均大于0,表明区域土壤存在重金属累积现象;8种重金属单项地积累指数均值大小顺序为As>Hg>Pb>Cd>Zn>Cr>Cu>Ni;Hg、As、Cd、Pb四元素明显高于其他元素,处于极强危害水平级别。潜在生态结果显示,整体处于极强危害水平,主要贡献因子为Hg、As等。

In this paper,14 topsoil samples from a gold mine in Hainan Province were taken as the research object,and 8 heavy metals such as Cu,Pb,Zn,Cr,Ni,Cd,AS and Hg were analyzed and determined.Single factor and Nemerow composite index method,ground accumulation index method and potential ecological risk index method were used to evaluate the degree of soil pollution caused by slag muck.Spearman analysis showed that 7 heavy metals such As Cr,Ni,Cu,Pb,Zn,Cd and As had strong correlation and came from ore.Hg is an exogenous heavy metal.The mean value of Nemerow index at 14 sites reached the moderate and severe pollution level,and the main contributing factors were Hg,As,Pb,Cd,etc.The soil accumulation results showed that the average value of heavy metal geological accumulation index at all sites was 3.2,which was greater than 0,indicating that there was heavy metal accumulation in regional soil.The average value of the accumulation index of 8 heavy metals was As>Hg>Pb>Cd>Zn>Cr>Cu>Ni.Hg,As,Cd,Pb four elements are significantly higher than other elements,in the extremely harmful level.The potential ecological results showed that the overall harm level was very strong,and the main contributing factors were Hg and As.