衡阳水口山铅锌矿区重金属污染现状的分析

Analysis on pollution of heavy metal in Shuikoushan Pb-Zn mining and smelting area in Hengyang

以衡阳水口山铅锌矿区及其周围地区为研究对象,采用单因子污染指数法和内梅罗综合污染指数法分析了自然土壤(A层、C层)样品中不同重金属(Pb、Zn、As、Cu、Cd、Hg)的污染特征和污染程度。结果表明:受铅锌选矿和冶炼活动的影响,研究区土壤明显受到重金属的污染,尤其是在严重污染区域,土壤中Pb、Cd、Cu、Zn、As、Hg含量最高分别达2691.88、28.91、376.91、135.91、1309.00、2.78 mg/kg。研究区4个地点中,Cd的单因子污染指数均大于其它5个指标,其综合污染指数大小顺序为尾沙坝>矿区农田>冶炼厂>康家湾采选地;其中冶炼厂和康家湾采选地中Cd的单因子污染指数最大,高达273.78,Cu最小,也达到7.83,两地点单因子污染指数大小顺序均为:Cd>Hg>Pb>As>Zn>Cu;尾砂坝和农田中Cd的单因子污染指数最大,达到93.03,Zn最小,为1.14,两地点单因子污染指数大小顺序均为:Cd>Pb>As>Cu>Hg>Zn。研究区土壤中重金属综合污染已相当严重,4个地点综合污染级别均超过最大污染级别4,其中存在着严重的Cd、Pb、Hg和轻度的Zn、As复合污染。

By using single-factor pollution index and Nemerow pollution index method, the pollution degree and pollution characteristics of heavy metal （ Pb, Zn, As, Cu, Cd and Hg） in the national soil samples（A horizon and C horizon ） in Shuikoushan Pb/Zn mining and smelting area and surrounding areas in Hengyang, Hunan. The results show that the soils of the studying area were subject to heavy metal pollution, especially in the serious pollution regions, affected by lead and zinc ore dressing and smelting activities, and the contents ofPb, Cd, Cu, Zn, As and Hg in soils were up to 2691.88, 28.91,376.91, 135.91, 1309.00, 2.78 mg / kg. The four sites in the study area, the Cd single factor pollution index was greater than the other five indicators, Nemerow pollution index ordered from big to small： Weishaba〉Nongtian〉Yelianchang〉Kangjiawan; the yelianchang and the Kangjiawan＇ s Cd single factor pollution index were the biggest, up to 273.78, that of Cu were the minimum, being 7.83, the two sites＇ single factor pollution index ordered by magnitude： Cd〉 Hg〉 Pb〉 As〉 Zn〉 Cu; Weishaba and Nongtian＇ s Cd single-factor pollution index were the biggest, up to 93.03 and that of Zn were the smallest, being 1 .14, the two sites＇ single factor pollution index were in the order： Cd〉 Pb〉 As〉 Cu〉 Hg〉 Zn. The soil heavy metal comprehensive pollution is relatively serious in the four tested mining areas, integrated pollution level of the four sites exceed the maximum contamination 4 level, there were serious degree Cd and Pb, Hg and mild degree of Zn, As combined pollution.