中国西北某煤化工区土壤中重金属污染特征及其源解析

为明确煤化工区内土壤中重金属的污染状况及其来源,本文选定我国西北某大型煤化工区的土壤样品、原煤样品和煤灰样品,通过消解后应用ICP-MS和冷原子吸收等方法对样品中Cr、Cd、As、Pb、Ni、Se、Hg等8种元素含量进行测定。选用富集因子法、相关系数分析法、聚类分析法和因子分析法等数学方法,对煤化工区土壤中的重金属进行污染评价和来源解析。结果表明:Cr、As、Se、Ag、Cd属于人为源,依据数据模型以及土壤、煤和煤灰中重金属迁移规律分析,推定区域内土壤重金属来源主要有三种污染源。其中,煤气化污染源主要负载Se、Cd、Pb,其对区域土壤中重金属的总贡献率为32.01%;渣场扬尘等主要负载Cr、Ag和Hg,对区域内土壤中重金属的总贡献率为23.89%;交通等外来污染源主要负载As、Ni等,对区域内土壤中重金属的总贡献率为19.61%。

The characteristics and source apportionment of heavy metal pollution in the soil at a coal chemical industry area in northwest China

This paper aims to investigate the heavy metal pollution in the soil at a large coal chemical industry area in northwest China,and perform the source apportionment of the pollution.Soil samples,raw coal and coal ash samples were taken from that area and were analysed with ICP-MS and cold atomic absorption method after digestion for determining 8 heavy metal elements including Cr,Cd,As,Pb,Ni,Se and Hg.Enrichment factor method,correlation coefficient analysis,cluster analysis and factor analysis method were used to evaluate the pollution and analyse the sources.Results indicated that the Cr,As,Se,Ag,and Cd were from the anthropogenic activity,and there were three main sources of pollution according to the data field model and the migration regularity of heavy metals in soil,coal and coal ash.Among the three pollution sources,coal gasification pollution was primarily loaded with Se,Cd,and Pb; slag field dust was mainly loaded with Cr,Hg and Ag; other external sources such as from traffic were mainly loaded with As,and Ni.The three sources contributed 32.01%,23.89% and 19.61% to the heavy metal pollution in the soil,respectively.