嘉峪关市北部土壤重金属分布特征及评价

Distribution and assessment of soil heavy metals in northern Jiayuguan City, China

以嘉峪关市北部工业园区的MF化工厂为中心,展开对周边土壤的重金属元素分布特征研究并进行环境评价.通过267个样品的重金属元素分析,得出重金属元素平均w(Pb)=4.454×10-5、w(Ni)=4.389×10-5、w(Cu)=4.394×10-5、w(Cr)=6.9817×10-4和w(Cd)=2.6×10-7,分别超出中国土壤元素背景值89%、88%、120%、1195%和255%,表现为显著的元素富集.用地累积指数法和富集因子法结合重金属元素质量分数,对研究区土壤重金属富集程度进行评价,发现Pb和Cd主要富集在生活垃圾堆放处和废弃工厂的周围,Ni,Cr和Cu在厂区和工业废渣堆积区附近富集.

The heavy mental contamination surrounding the MF chemical plant in the industrial park of north Jiayuguan City was explored and assessed.Based on the analysis of heavy metal elements,a conclusion could be drawn that w(Pb)=4.454×10-5,w(Ni)=4.389×10-5,w(Cu)=4.394×10-5,w(Cr)=6.9817×10-4 and w(Cd)=2.6×10-7 surpassed the background values of Chinese soil elements by 89%,88%,120%,1195%and 255%respectively.According to the index of geoaccumulation and enrichment factors linking with the distribution of heavy metal elements,we assessed the extent of heavy metal enrichment,and especially researched into the differences between the indexes of geoaccumulation,enrichment factors and concentrations of heavy metal elements,with the results that Pb and Cd mainlyenriched at the domestic rubbish piles and around the displaced plant;Ni,Cr,and Cu enriched near the industrial plant and dross piles.