秦岭山区尾矿库周边耕地土壤重金属污染特征研究

Distribution Characteristics of Heavy Metal Pollution in Cultivated Land Around Tailings Reservoir in Shangzhou

研究尾矿库周边耕地土壤重金属污染特征对矿区耕地治理和保护至关重要。以地处秦岭山区的陕西省商洛市商州区董家沟、南沟、小西沟和王坡子沟尾矿库周边耕地为研究对象,测定了耕地耕层土壤中主要的重金属元素Cd、Cu、Pb、Cr、Zn、Ni,运用单因子污染指数法和综合污染指数法评价土壤中重金属元素的污染。结果表明:(1)除南沟尾矿库周边耕地外,其他3个尾矿库周边耕地土壤重金属元素Cd、Cu、Pb、Cr、Zn、Ni含量随着距尾矿库距离的增加而递减;(2)南沟尾矿库周边耕地污染最严重,属于重度污染,其他尾矿库周边耕地土壤的污染程度处于中度、轻度与尚清洁状态;(3)尾矿库周边耕地土壤重金属元素的综合污染指数均值为2.34,属于中度污染状态。研究可为秦岭山区尾矿区周边耕地重金属污染治理提供理论依据。

It is very important to study the characteristics of heavy metal pollution in the cultivated land around tailings pond for protection of cultivated land in mining area.In order to study the pollution of heavy metals in the soil around Shangzhou tailing pond,this paper took the farmland around the Dong Jiagou,Nan Gou,Xiao Xigou and Wang Pozigou tailing pool as the study area,Cd,Cu,Pb,Cr,Zn and Ni in soil were determined.The pollution of heavy metals in soil was evaluated and analyzed by using single factor pollution index and comprehensive pollution index method.The result showed that:(1)In addition to the cultivated land soil a-round Nan Gou tailing pond,the metal content in the studied area decreased with the distance from the tailing pond to the periphery,which indicated that the soil pollution mainly came from the tailing pond mining of the surrounding farmland.(2)The most serious pollution of farmland around the tailings reservoir was in Nangou tailing pond,while the pollution degree of other tailing pond were moderate,light and still in a clean state.(3)The mean value of the comprehensive pollution index of heavy metal elements in tailings in Shangzhou District was 2.34,which indicated that the cultivated land soil was in a moderate state of around tailings reser-voir.The research could provides the theory basis for heavy metal pollution control in the cultivated land a-round tailings pond in Qinling mountains.