某铅锌尾矿库周边土壤重金属污染特征及其来源分析

以某铅锌尾矿库周边土壤为研究对象，测定土壤中Cd、Hg、As、Pb、Cr、Cu、Zn、Ni重金属含量，采用地质统计分析掌握重金属含量空间分布，再利用单因子污染指数、内梅罗综合污染指数和地质累积指数评价重金属污染状况，并结合相关性分析和主成分分析探重金属来源。结果表明，土壤中Cd、Hg、As、Pb、Cr、Cu、Zn、Ni平均含量分别为10.4、1.54、132、653、62.8、73.8、1 392、31.6 mg/kg，越靠近尾矿库，Cd、As、Pb、Cu、Zn、Hg含量越高。内梅罗综合污染指数表明，研究区综合污染指数为11.2，为重污染，单因子污染指数和地质累积指数表明，研究区土壤Cd污染最严重，其次是As、Zn、Pb、Cu、Hg污染，Cr和Ni无污染。相关性分析和主成分分析表明，Cd、Hg、As、Pb、Zn之间存在显著正相关关系，主要受铅锌尾矿库长期堆存、转运及加工等人为活动影响，Cr、Ni主要来自土壤母质，Cu主要受矿业活动和农业活动共同影响。

Pollution Characteristics and Source Analysis of Heavy Metals in Soils of a Lead-Zinc Tailings Pond

In this paper, contents of Cd, Hg, As, Pb, Cr, Cu, Zn and Ni were determined in soils around Typical Lead-zinc Tailings Reservoir of Shizhu in southeast Chongqing. Spatial distributions of heavy metal content on soil was mastered by geostatistics analysis. Pollution statuses of heavy metals were assessed by methods of single factor pollution index, Nemerow pollution index and Muller index, and sources of heavy metals were explored with correlation analysis and principal component analysis. The results showed that average contents of Cd, Hg, as, Pb, Cr, Cu, Zn and Ni in soil (mg/kg): 10.4, 1.54, 132, 653, 62.8, 73.8, 1392, 31.6. The higher the contents of Cd, As, Pb, Cu, Zn and Hg when the closer to the lead-zinc tailings reservoir. The results of Nemerow pollution index analysis showed that the comprehensive pollution index is 11.2 in the study area, which is heavy pollution. single factor pollution index and Muller index analysis showed that Cd is the most serious pollution in the study area, followed by As, Zn, Pb, Cu and Hg, and Cr, Ni is no pollution. Correlation analysis and principal component analysis showed that Cd, Hg, As, Pb, Zn were positively correlated with each other. mainly originated from human activities, such as lead zinc ore stacking, transfer and processing, Ni and Cr mainly originated from soil parent materials, and Cu was affected from mining operations and agricultural activities.