湖南某石煤矿区重金属污染现状及生态风险评价

Current Situation of Heavy Metal Pollution and Ecological Risk Assessment of Stone Coal Mine in Hunan Province

为研究湖南某石煤矿区重金属污染现状,采用ICP法测定了水体和土壤中多种重金属含量,并分别采用内梅罗污染指数法和潜在生态危害指数法进行风险评价。结果表明,水中Cd、Cr(Ⅵ)、Zn、Fe和Mn平均浓度分别为1.935 5、0.025 3、6.024 9、16.222 0和4.214 9 mg/L,污染指数分别为387.10、5.06、3.01、54.07和42.15,污染程度从大到小排序为:Cd>Fe>Mn>Cr(Ⅵ)>Zn;土壤中Pb、Zn、Cr、As、Hg和Cd平均含量分别为8.51、38.59、18.65、10.01、0.18和3.41 mg/kg,平均生态风险系数分别为2.13、0.98、0.85、18.00、28.55和339.80,污染程度从大到小排序为:Cd>Hg>As>Pb>Zn>Cr,整个矿区的综合潜在生态风险指数为390.31,污染程度为较高生态危险。矿区受到多种重金属复合污染,废石堆和沉淀池的排水口下游区域较严重。

To investigate the current situation of heavy metal pollution in a stone coal mine in Hunan Province,the content of Cd,Hg,As,Pb,Cr,Cr(Ⅵ),Zn,Fe,and Mn in water and soil samples was determined by using ICP,and the risk of heavy metal pollution was evaluated by using the Nemerow pollution index and potential ecological hazard index respectively.The results show that concentrations of Cd,Cr(Ⅵ),Zn,Fe and Mn in water are 1.9355,0.0253,6.0249,16.2220 and 4.2149 mg/L on average,with pollution indices of 387.10,5.06,3.01,54.07 and 42.15,presenting the pollution degree in the following descending order:Cd>Fe>Mn>Cr(Ⅵ)>Zn;while content of Pb、Zn、Cr、As、Hg and Cd in the soil is 8.51,38.59,18.65,10.01,0.18 and 3.41 mg/kg on average,with ecological risk coefficient of 2.13,0.98,0.85,18.00,28.55 and 339.80 on average,presenting pollution degree in the following descending order:Cd>Hg>As>Pb>Zn>Cr.It is shown that the comprehensive potential ecological risk indices of the whole mine is 390.31,indicating a higher ecological pollution risk.The mine area is polluted by several kinds of heavy metals,especially in the downstream areas of waste dump and sedimentation tank.