应用物元分析法评价矿区周边土壤重金属污染的变化

Pollution Evaluation of Soil Heavy Metal around Mining Using Matter Element Analysis

为分析煤矿开采对土壤重金属污染水平的影响,尝试利用物元分析和主成分分析（PCA）方法对宿州市矿区周边土壤重金属污染水平进行评价。结果表明：（1）煤矿开采、堆放对土壤重金属污染具有重要影响,与非矿区背景值相比,Cr含量达到非矿区土壤背景值的2~4.17倍,Cd含量达到非矿区土壤背景值的1~3.05倍,Pb和Cu含量达到非矿区土壤背景值的2倍左右,As的含量略高于非矿区土壤背景值。（2）综合关联度结果显示,土壤重金属污染在100 m处未达到轻度污染的标准要求,但具备向轻度污染转化的条件;200 m和400 m处分别达到轻度污染和清洁等级要求,但隶属该等级的程度不强,且随着距离增大土壤重金属含量和污染程度均在下降。（3）物元模型能够揭示每个土壤重金属元素的分异信息和综合评价的中间信息,适用于土壤重金属污染水平评价。

With intense industrialization, soil heavy metal pollution had become a serious environmental problem, and drew great attention because of its potential threat to detrimental effects on the ecosystem and human health. In order to analyze the impact of soil heavy metal pollution due to coal mining, a total of 40 soil samples at depth 0- 20 cm were collected in every coal mining area, and the contents of seven heavy metals（Zn, Cr, Cd, Pb, Cu, As and Hg） were determined to evaluate pollution level of soil heavy metal around different distance of mining area in Suzhou, Anhui Province based on the model of matter element analysis and principal component analysis. The results showed that：（1）There was an important impact of coal mining and stacking on soil heavy metal pollution. The contents of Cr mining area were 2- 4.17 times higher than that of soil background, as well as, Cd was 1~3.05 times, Pb and Cu were twice and As was slightly higher.（2） The model of matter element analysis indicated that the pollution level of soil heavy metal did not reach but tended to the standard of light pollution degree at the 100 m distance, and reached the standard of light pollution and clean degree at the 200 m and 400 m distance. However, both of them belonged to the levels of degree was not strong, which illustrated soil environmental quality was within the scope of soil self-purification. More attention should be paid to protect soil environment and avoid soil pollution during coal mining and agricultural production in the future. And, along with the distance increasing, the content of soil heavy metal and the degree of pollution were falling.（3） The result also showed that the matter element model was suitable to assess soil heavy metal pollution level, because it could reveal the different information of every single element and the middle state information of the whole evaluation.