Research On Pollution Source And Transfer Distribution Of Heavy Metals To The Soil In Huainan Mining Area

The coal mining have made great contributions to the economic development in China,but it also caused caused seriousimpact on soil environment in mining area,resulting damaged to the ecological environment and human health.This aricle is based on the Huainan mining area and focused on the key mine area of Huainan mining area, analysising on the content of heavy metals in soil, offering the distribution of heavy metals in soil in mining area parsing out pollution source of heavy metal pollution in soil.Based on the ion of the geo accumulation index method、enrichment factor method and the grey relational analysis, putting forward the grey relational analysis method modified enrichment coefficient to evaluate the pollution status of heavy metal to the soil mining area;at the same time,evaluating the ecological risk of mining area and putting forward the ecological restoration measures in order to provide the guidance and theoretical basis for the regional environmental quality and the prevention of heavy metal pollution in Huainan mining area.In this paper, respectively using the geo accumulation index method,the enrichment factor method and gray correlation analysis method to evaluate the pollution status of heavy metal mining area.The index of geoaccumulation showed that the contaminated area is 97.9% within the scope of the study area, The enrichment factor method showed that the enrichment coefficient of heavy metals in the soil of in Xinzhuangzi mine,Panyi Mine and Guqiao Mine generally is 8.22、7.57 and 7.55,all of them belong to the heavy pollution;but the conclusion of grey relational analysis shows that it is the level of cleanliness.Obviously,results is of great error. In view of this, putting forward the grey relational analysis method based on the modified enrichment coefficient to modify the grey relational analysis method and redefine the evaluation standard of grading. The results indicate that the quality of soil belong to moderate pollution, which is the level of III.It is reflected the actual pollution degree of mining area, indicates that the proposed approach is a feasible evaluation method which can overcome the drawbacks of two kinds of evaluation method.According to the distribution characteristics of heavy metal,it shows that with the change of the mining time and the mining capacity, different heavy metal elements show the different distribution characteristics.This maybe due to the diversified sources of the heavy metal pollution and also can be caused by the weathering migration and occurrence state of heavy metals in coal gangue.The tracing analysis results revealed that As、Zn and Pb have similar source and they are mainly affected by the mining activities and transportation; Cu and Cr have similar source and they mostly come from the soil parent material, and they are less affected by coal exploitation;The source of Cd pollution which maybe from the use of chemical fertilizer,phosphate fertilizer and the long-term mining activities is different from the other elements.The ecological risk assessment shows that Cd ecological risk is the most serious, 31.9% sampling points belong to the strong risk level; the second element is As,25.5% of the sampling points belong to the medium risk level. Comprehensive potential ecological risk index RI display that the potential ecological risk degree from high to low is:Xinzhuangzi mine(112.54)> Guqiao Mine(109.40)>Panyi mine(104.60).