准格尔旗铧尖地区土壤重金属地球化学特征及污染评价

Geochemical Characteristics and Pollution Evaluation of Heavy Metals in Soil in Huajian Area of Zhungeer Banner

摘要: 为了解准格尔旗铧尖地区土壤重金属空间分布及污染情况，采用公里网格法对研究区布设土壤样品点位，对铧尖地区As、Hg、Cu、Pb、Ni、Cd、Zn七种重金属元素进行了测定分析，并运用多元统计法、富集指数法、内梅罗综合污染指数法以及潜在生态风险指数法研究了研究区土壤重金属污染程度。结果表明：研究区Pb、Cd元素平均含量分别为内蒙古土壤元素背景值1.83、3.02倍，显著富集；同时Pb、Cd元素两种元素变异系数大于1，属超强变异元素。As、Hg、Cu、Zn属强变异元素，Ni元素属弱变异元素；Pb、Zn、Cd三种具显著相关性，Hg与Cu具显著相关性，推测其分别具有同源性或同期性，出现不同种元素间协同污染的概率较大；As、Hg、Cu、Pb、Cd、Zn六种元素污染程度均达到严重污染，只有Ni元素为轻度污染；Cd元素潜在生态风险指数平均值最高(89.6381)，评价结果为较重危害水平；其余六种元素按潜在生态风险指数依次为Hg > As > Pb > Ni > Cu > Zn，评价结果为轻微危害；研究区内五处中高风险区为采矿活动在地表径流作用下元素富集的结果。

Abstract: In order to understand the spatial distribution and pollution of heavy metals in Huajian area of Zhungeer Banner, this study adopted the kilometer grid method to set up soil sample sites, determined and analyzed seven heavy metal elements (As, Hg, Cu, Pb, Ni, Cd, Zn) in Huajian area, and studied the pollution degree of the study area by multivariate statistical method, enrichment index method, Nemero comprehensive pollution index method and potential ecological risk index method. The results showed that the average contents of Pb and Cd elements in the study area were 1.83, 3.02 times higher than those of soil elements in Inner Mongolia, respectively, and were significantly enriched, while the coefficients of variation of Pb and Cd elements were more than 1, indicating that they belonged to super-strong variation elements. As, Hg, Cu and Zn belong to strong variation elements, Ni elements belong to weak variation elements, Pb, Zn and Cd have significant correlation, Hg and Cu have significant correlation, it is speculated that they have homology or synchronization respectively, and there is a high probability of synergistic pollution among different elements. The pollution degree of As, Hg, Cu, Pb, Cd and Zn all reached serious pollution, only Ni element was slightly polluted. The average value of potential ecological risk index of Cd element is the highest (89.6381), and the evaluation result is more serious; the order of potential ecological risk index of the other six elements is Hg > As > Pb > Ni > Cu > Zn, and the evaluation result is slight hazard; five medium and high risk areas in the study area are the result of element enrichment of mining activities under the action of surface runoff.