南京市表层土壤重金属污染特征及污染来源

以南京市表层土壤为对象,研究了南京市不同功能区土壤重金属的污染特征,并采用主成分分析法对南京市土壤重金属的主要可能来源予以判别。结果表明：重金属污染主要在工业区和交通繁忙区相对较重,而居民区和公园区的重金属污染相对较轻。从本次调查的土壤重金属污染水平的对应分析结果来看,重金属Pb的富集系数为3.21,表现为强富集;而Cu、Zn的富集系数分别为：1.72和1.80,表现为一定的弱富集;Cr和N i的富集系数分别为0.99和1.00表现相对贫化,基本与背景值较接近.对南京市土壤重金属主成分分析结果表明：南京市市区的土壤重金属污染主要来自于交通排放和工业释放;同时,也应该看到对于城市公园和居民住宅区,城市垃圾、市政工程等也是目前环境污染的一个重要原因。

Study on the Characteristics and the Origin of Heavy Metal Pollution in Different Functional Regions of Nanjing

Thirty soil samples collected from residential area,park,intense traffic areas and industry regions respectively in Nanjing were analyzed for Zn,Pb,Cu,Cr and Ni.Principal component analysis was applied to identify the sources of heavy metal.The mean concentrations of Cu,Zn,Pb,Cr and Ni of the soil of all kinds of functional regions were 55.3,138,79.6,58.3,35.7 mg/kg-1,respectively.Compared to the background value of Nanjing,Pb is strongest enriched elements,concentration enrichment ratio is 3.21.Cu and Zn are moderately enriched elements,and their concentration enrichment ratio are 1.72 and 1.80 respectively.Cr and Ni are close to the background values.Their concentration enrichment ratios are 0.99 and 1.00 respectively.Principal component analysis showed the sources of topsoil heavy metal should be vehicular source and industrial contamination.Municipal solid waste maybe an important sources.