奎屯垦区地方性重金属污染评价及剖面分布特征

Endemic Heavy Metals Pollution Assessment and Its Distribution in Soil Profile in Kuitun Region

以奎屯垦区123团典型地方性重金属污染区为研究区域,通过测定0～20、20～40、40～60、60～80、80～100cm各土层土壤的Cd、As、Cu、Zn含量,揭示其剖面分布特征。通过单项污染指数法和尼梅罗综合指数法,并结合国家《土壤环境质量标(GB15618-1995)》的Ⅱ级评价标准,对土壤的重金属污染状况进行了评价。结果表明:奎屯垦区123团的重金属单因子污染指数由大到小为Cd>As>Cu>Zn,尼梅罗综合污染指数为1.71,已达到土壤3级污染水平。该区域土壤重金属污染以Cd污染为主,其次是As,而Cu和Zn未达到污染水平。本文首次提出奎屯垦区重金属污染具有Cd-As复合污染的特性。

In the present study,heavy metals including Cd,As,Cu and Zn distribution in different layers of soil profile（0~20,20~40,40~60,60~80,80~100 cm） were determined.Two methods including single factor index and nemerow pollution index were employed to evaluate heavy metal pollution level based on heavy metal national quality standard GB15618-1995（Ⅱ）.Our research area located in 123 state farm unit in Kuitun region,Xinjiang.The order of soil heavy metal pollution evaluated by single factor index method is CdAsCuZn,and by method of nemerow pollution index,pollution degree value already reached to 1.71,which means soil heavy metal pollution in researching area belonging to 3 grade.Moreover,from single pollution index order and heavy metal concentration in top layer of soil we can make a conclusion that soil heavy metal pollution occurred in 123 farm unit in Kuitun region is Cd-As compound pollution,the mainly source of heavy metal element is Cadmium,followed by Arsenic,however,elements of Cu and Zn haven＇t reached to pollution rate yet.Briefly,our research show soil heavy metal pollution in investigated area belongs to Cd-As compound pollution.Soil Cd and As contents have no statistically significant difference among different soil vertical depth,indicating soil parent material and underground water quality play a major role to soil Cd-As compound pollution in Kuitun region.