四川省某铅锌矿尾矿库周边环境重金属污染特征

Polluted characteristics of heavy metals in surrounding environment near a Pb-Zn mine tailing in Sichuan Province

摘要对四川省某铅锌尾矿库周边土壤、地表水和地下水中的重金属含量及其相关性进行了研究。结果表明：（1）尾矿库周边土壤中Pb、zn、Cd、As分别为19．8-187．o、11．6-249．0、O．O1～3．44、2．6～9．3mg／kg。土壤中重金属元素都存在一定的相关性，Pb与zn相关系数为O．951，达到极显著相关。（2）尾矿库周边土壤并未受到大面积的重金属污染，综合污染指数平均值为0．98，而选矿厂废水排放至尾矿库的明渠、尾矿库渗滤液排水沟附近土壤污染达到中污染水平。（3）尾矿库尾砂堆积处两翼地下水中有一定Pb污染，推断因为尾砂深度堆积与地下水直接接触。（4）含高浓度硫酸盐的尾矿库废水携重金属沿尾矿库重力坝下渗，对尾矿库渗滤液排放口下游区土壤、地下水造成了重金属和硫酸盐污染。

Abstract： An investigation of heavy metal in the soil,surface water and groundwater was carried out near a Pb- Zn mine tailing in Sichuan province. The results showed： （1） The contents of Pb, Zn,Cd and As in soils surrounded the tailings were range from 19.8 to 187.0 mg/kg,11.6 to 249.0 mg/kg,0.01 to 3.44 mg/kg and 2.6 to 9.3 mg/kg respectively. Positive linear relations were found between any two contents of the four heavy metals, especially the coef- ficient between Pb and Zn reaching to 0.951 as highly significant correlation. （2） The surrounding soil had not been widespread polluted,as the average nemerow integrated pollution index was 0.98. Only near the ditch in which carried the waste water from the ore treatment plant and under the tailing dam where the infiltrated water came together to form a stream, the pollution intension of the soil samples was medium polluted. （3） Pb contamination in the groundw- ater was found near the two flanks of the tailing dam, possibly for the heap of the tailings was so deep that had some direct contact with the groundwater. （4） The sulfate-rich water in the tailing pond carrying heavy metal infiltrated through the dam and caused heavy metal and sulfates pollution of the downstream soil and groundwater.