南京城市土壤重金属含量及空间分布特征

Heavy Metal Concentrations and Their Spatial Distribution in Urban Soils of Nanjing

研究了南京城市土壤重金属含量、来源及空间分布特征。结果表明,南京城市土壤中V、Mn、Co、Ni、Cr污染不明显,但受到了不同程度的Cu、Pb、Zn、Sb、Hg、Cd污染,其中Hg污染比较严重。V、Mn、Co、Ni、Cr含量之间均呈极显著正相父;Cu、Pb、Zn、Sb、Hg、Cd含量之间也均呈极显著正相关。南京城市土壤V、Mn、Co、Ni、Cr主要继承了原土物质;Hg、Cd、Pb主要来源于城市燃煤、机动车尾气及工厂排放粉尘;Sb主要来源于机动车尾气和工厂排放粉尘。南京城市土壤Hg、Cd、Pb、Sb含量空间分布规律非常相似,均表现为外围向市中心有逐渐增加的趋势,并且在新街口—鼓楼、梅山硫铁矿形成异常高值的岛状、环状区域。

The concentration and source of heavy metals in urban soils of Nanjing and their spatial distribution were studied. The results showed that the urban soils in Nanjing were not evidently polluted by V,Mn,Co,Ni and Cr, but contaminated by Cu, Pb, Zn, Sb, Cd to varying degrees and especially Hg to some extent. There were positive correlations among V, Mn, Co, Ni, and Cr concentrations, as well as among Cu, Pb, Zn, Sb, Cd and Hg concentrations. V, Mn, Co, Ni and Cr were originated from soils. Hg, Cd and Pb were mainly originated from coal burning wastes, vehicle emissions and industrial dusts.Sb were primarily originated from vehicle emissions and industrial dusts.The characteristics of spatial distribution of Hg, Cd, Pb and Sb were similar.They all possessed similar increasing trend from outward city to the center which showed similar spatial distributions highlighting two significantly high concentration zones corresponding to: (i) insular area in Xinjiekou - Gulou region; (ii) circular area in pyrites mine in Meishan region.