昆山市农用地土壤重金属污染现状及评价

为了解昆山市农用地土壤重金属的含量及其污染情况,通过调查、采样和实验室分析,并采用单因子污染指数法和内梅罗综合指数法对测定结果进行评价。结果表明,重金属平均含量分别为Cd 0.199mg/kg、Hg 0.199mg/kg、Pb 30.484mg/kg、Cr 87.729mg/kg、Cu 314.275mg/kg、Zn0.256 mg/kg、N i 31.083mg/kg、As 8.150 mg/kg。农用地土壤已受到不同程度的污染,主要污染物为Cd,其平均单项污染指数为13.525。除As外的其他重金属含量都高于土壤背景值,Cd、Hg、Cr、Pb存在着严重的点源污染,整个昆山市农用地土壤重金属污染区域差异比较明显。

Situation and Evaluation of Heavy Metals Contamination in Soil of Agro- land in Kunshan City

In order to know the contents and pollution of heavy metals in soil of agro-land in Kunshan city,investigation has been made,soil samples have been collected from the agro-land in Kunshan and the analysis of the soil heavy metal content in laboratory has been made,and single factor pollution index and Nemoro synthesis index have been adopted to evaluate heavy metal content in agro-land.The results show that average contents of heavy metals in the soil are as follows: Cd 0.199mg/kg,Hg 0.199mg/kg,As8.150 mg/kg,Pb 30.484 mg/kg,Cr 87.729mg/kg,Cu 314.275mg/kg,Zn0.256 mg/kg,Ni 31.083mg/kg,which suggests that the soils of the agro-land are contaminated to a different degree.The main contaminant is Cd,with a mean single pollution index of 13.525.The rest heavy metal content is higher than soil background value apart from As.Serious point pollution exists in Cd,Hg,Cr and Pb.Regional diversity of agro-land soil heavy metal pollution in Kunshan is relatively obvious.