某冶炼厂周边农田土壤重金属污染状况分析与评价

采用随机布点的方法采取冶炼厂周边农田土壤样品53个,分析了其中Cd、Cu、As、Pb、Zn的含量及部分样品中重金属的赋存形态,结合国家土壤环境质量标准和内梅罗污染指数法对土样进行分级评价。结果表明,该地区农田土壤受重金属综合污染程度依次为：Cd〉As〉Cu〉Zn〉Pb,其中水田土壤受Cd、Cu污染较旱地严重,受As污染略轻于旱地。水旱2种类型土壤中各重金属的形态分布规律相似,其中Cd以弱酸态和可还原态为主,Cu、As、Pb、Zn均以残渣态为主。

Analysis and Evaluation on Heavy Metal Pollution Condition of Soil in Farmland around One Smelting Factory

Fifty-three soil samples were collected from farmland around smelting factory by random distributed points method and the contents of Cd,Cu,As,Pb and Zn in the samples and the existing form of occurrence form in part samples were analyzed.Then the soil samples were graded and evaluated by combining national quality standard for soil environment with Nemero index.The results showed that the comprehensive pollution degrees of heavy metals in farmland soil of this area were as follows: Cd>As>Cu>Zn>Pb;among them the Cd and Cu pollution of soil in paddy field was more serious than that in dry land and its As pollution was less serious than that in dry land.The form distribution laws of various heavy metals in soil of paddy field and dry land were similar,among which Cd was mainly appeared in weak acid state and reducible and Cu,As,Pb and Zn were mainly appeared in residual state.