铅锌矿山开发导致的重金属在环境介质中的积累

Heavy Metal Accumulations in Environmental Media Induced by Lead and Zinc Mine Development in Northwestern Guizhou Province, China

以连续提取法和相关性分析研究了土法冶炼锌、铅锌和矿山开采导致的重金属在废渣及环境介质土壤、溪流沉积物中的积累,并分析了其环境危害性。结果显示,贵州赫章土法炼锌导致的重金属Pb、Zn、Cd在环境介质中的积累相当高。水城杉树林铅锌矿山开采引起的重金属积累则相对较低,但也明显高于背景值;土壤和沉积物中的铁矿物对重金属有强烈的固定作用。除残渣态外,Pb、Zn在土壤、炼锌废渣中主要呈铁锰氧化物结合态,沉积物中则为碳酸盐结合态。可交换态Pb、Zn含量变异较大,但在炼锌废渣、土壤中含量明显高于河流沉积物,暗示铅锌矿开发对土壤环境的潜在危害更大。

Sequential extraction technique and correlation analytical methods were applied for uncovering the environmental damages of heavy metals in soils and river sediments accumulated during zinc smelting with indigenous method and lead and zinc mining. Pb, Zn, Cd were more severely accumulated in soils and sediments caused by zinc smelting with indigenous approaches in Hezhang County than in those by lead and zinc mining in Shanshuling region in Shuicheng City. Correlation analyses indicate a strong fixation ability of iron minerals to metals for soils and sediments. Except for residue fractions, Fe and Mn oxide bound fractions for Pb, Zn overwhelm in soils and in slags, while carbonate bound fractions dominate in river sediments. Exchangeable metal fractions were higher in slags and soils than in sediments, which implies a more potential imperilment to soils than to sediments induced by lead and zinc mine development.