工业集聚区土壤和农作物重金属赋存特征解析

Analysis of Characteristics of Heavy Metal Accumulation in Soil and Crops in Industrial Agglomeration Zone

为系统研究工业集聚区土壤和农作物重金属污染,对工业集聚区不同方位、不同距离的土壤和小麦重金属含量进行测定,采用单因子污染指数法、内梅罗综合污染指数法(Nemerocompositepollutionindex,NPI)及生物富集系数法进行分析。结果表明,工业集聚区内土壤和小麦重金属污染严重(NPI>2),工业集聚区外至5km范围内,除汞(Hg)、铅(Pb)和锌(Zn)污染较轻,其他重金属污染相对较严重(NPI>1),工业集聚区5km范围之外土壤和小麦重金属污染相对小(NPI<1)。同时小麦重金属含量与土壤重金属含量存在显著相关性,主要食用组织籽粒中镉(Cd)、Hg、Pb、镍(Ni)、砷(As)与土壤重金属含量呈正相关,相关系数分别为0.484、0.409、0.018、0.679,0.480,籽粒中铬(Cr)与土壤重金属含量呈负相关,相关系数为-0.133。依据研究结果,建议工业集聚区内不宜种植农作物(小麦),工业集聚区外至5km范围内种植的小麦只可食用籽粒,工业集聚区5km范围之外可安全开展农作物(小麦)生产。

In order to systematically study on heavy metal pollution in soil and crops in industrial agglomeration area,the heavy metal content of soil and crops wheat in different directions and distances of industrial agglomeration area were determined and analyzed by single factor pollution index,Nemerow pollution index(NPI)and bioconcentration factors methods.The results showed that the heavy metal pollution of soil and crops wheat in the industrial agglomeration area were serious(NPI>2).Within the influence range of 5 km from the industrial agglomeration area,except for mercury(Hg),plumbum(Pb)and zinc(Zn),other heavy metals were relatively serious(NPI>1),the heavy metal pollution outside the 5 km range was relatively light(NPI<1).In addition,there were significant correlation between heavy metal content in crops and soil,among which cadmium(Cd),mercury(Hg),plumbum(Pb),nickel(Ni)and arsenic(As)in wheat grains were positively correlated with soil heavy metals,with correlation coefficients of 0.484,0.409,0.018,0.679 and 0.480,respectively,while chromium(Cr)in grains were negatively correlated with soil heavy metals with a correlation coefficient of-0.133.The results indicated that wheat should not be planted in the industrial agglomeration area,and crops(wheat)planted within 5 km from the industrial agglomeration area only could be consumed as grains.Crops(wheat)production could be safely carried out 5 km away from the industrial agglomeration area.