内蒙古草原白乃庙铜矿区土壤重金属污染特征研究

对位于内蒙古荒漠草原上的白乃庙铜矿采选矿区土壤和尾矿区周围土壤重金属污染状况进行了调查研究。结果表明,矿区土壤中Cu、Cr、Ni、Fe和Mn浓度均高于内蒙古土壤平均值。单因子指数法评价结果表明,五个调查区域土壤都受到了重金属Cu、Cr、Ni、Mn、Fe的污染,其中Cu为重污染,Cr、Ni、Mn、Fe为轻污染,Pb为安全级别,Zn和As只对某些区域有轻污染。综合污染指数法评价结果表明,五个调查区域的土壤重金属污染等级均属重污染,主要贡献元素是Cu,其次是Cr、Ni、Mn、Fe,这与尾矿砂中这些重金属的浓度是相对应的。由于周边地形复杂,多为低山丘陵,所以该地区主导风向对于尾矿库区不同方向土壤重金属污染水平的影响差异并不显著。

Characteristics of Heavy Metals in Soils from Bainaimiao Copper Mining Area of Grassland Ecosystem in Inner Mongolia

The pollution status and total concentrations of soil heavy metals were analyzed in the mining,ore-dressing area and around the tailing reservoir of Bainaimiao copper mine,which located in the desert steppe of Inner Mongolia.The results indicted that the average concentrations of Cu,Cr,Ni,Fe and Mn were higher than the average concentrations of Inner Mongolia.According to the single factor pollution index,soils from the five investigated areas were contaminated by Cu,Cr,Ni,Mn and Fe.Soils from Bainaimiao mine were seriously polluted by Cu,slightly polluted by Cr,Ni,Mn,Fe,and not polluted by Pb,while Zn and As only contaminated some areas slightly.According to Nemerow integrated pollution index,soils from the five investigated areas were seriously contaminated by heavy metals.The main pollution elements were Cu,Cr,Ni,Fe and Mn,of which Cu was the uppermost.The pollution condition of soil heavy metals in copper mining area was consistent with the concentrations of tailings.Because the surrounding terrain of the mining area was complex and the region had a lot of hills,the local dominant wind had no significant effect on the heavy metals pollution level around the tailing reservoir.