城市工业区土壤重金属累积特征与来源解析——以上海市闵行区典型工业区为例

Accumulation and source apportionment of heavy metals in urbanindustrial soils-A case study in Minhang District of Shanghai

为了掌握城市工业区土壤重金属污染状况与来源,以上海市闵行区典型工业区为例,对该工业区表层土壤(0—20 cm)重金属(As、Pb、Cu、Zn、Cr、Cd、Hg和Ni)的累积状况、空间分布特征与污染来源进行分析与评价.结果表明,土壤重金属As、Pb、Cu、Zn、Cr、Cd、Hg和Ni的含量均值分别为7.80、9.49、41.11、150.67、90.48、0.27、0.14、35.57 mg·kg^(-1).与上海市土壤背景值相比,除As、Pb外,其余重金属平均含量均高于其背景值.空间上,As元素含量的分布西部区域低于东部区域;Cr、Hg和Ni在空间分布上具有一定程度的相似性,在研究区东北部含量低于其他区域;Cr元素在空间上呈带状分布与局部岛状分布,位于研究区中部的工业区累积集中程度相对较高;Hg和Ni元素在空间上主要呈带状分布;Pb元素空间变异大,高值区位于东部的食品工业区和印刷工业区.综合单因子污染指数、内梅罗综合污染指数和地累积指数评价结果表明,Zn、Cd和Cu的累积程度较高.总体上,研究区土壤重金属尚未达到污染水平.主成分-多元线性回归模型(PCA-MLR)表明,人为源占主体,约为93.2%.

To study the situation of urban-industrial soils,the spatial distribution,sources,and pollution level of heavy metals(Cd,Hg,As,Pb,Cu,Cr,Zn,and Ni)in Minhang District of Shanghai,as a case study,were investigated.The results showed that:(1)The average contents of soil As,Pb,Cu,Zn,Cr,Cd,Hg,and Ni were 7.80,9.49,41.11,150.67,90.48,0.27,0.14,and 35.57 mg·kg^(-1),respectively.Compared with the background values of heavy metals in soil in Shanghai,except for As and Pb,the average contents of other heavy metals were higher than their background values.(2)Spatially,the distribution of As contents in the western region were lower than that of the eastern region.Cr,Hg,and Ni had a certain degree of similarity in spatial distribution,and the contents of them in the northeast of the study area were lower than other regions.Distribution of Cr contents were in the shape of band and island,the accumulation concentration of the industrial area in the middle of the study area was relatively high.Hg and Ni contents were mainly banded in space.Pb had spatial variation significantly,and the high-value areas were located in the eastern food industry area and printing industry area.(3)Combined single factor pollution index,Nemerow comprehensive pollution index,and index of geo-accumulation to evaluate the polluted levels comprehensively,the results demonstrated the accumulation level of Cu,Zn,and Cd were high.In general,soil in the studied area is dominated by uncontaminated soil samples.(4)Principal component analysis-multiple linear regression model(PCA-MLR)showed that the anthropogenic source was attributed to 93.2%.