| In recent years, considerable attention has been paid to the problem of soil contamination with heavy metals to prevent further environmental deterioration and to examine applicable methods of soil remediation. In this case study, the contents and vertical distribution of heavy metals（Cd, Cu, Zn, Cr, Pb） in soils around two collieries in Shenfu Coal Mine Area were analyzed, and the pollution degree and potential ecological risks of the heavy metals were evaluated by the Potential Ecological Risk Index. The results indicated that（1）The change trends of heavy metals in the 0~60 cm soil profile were similar between two collieries, and the content of soil heavy metals in Sidaogou Colliery was higher than that of Liangshuijing Colliery;（2）The average contents of cadmium in soils surrounding two Collieries were higher than the national soil background value（0.20 mg·kg-1）, which were 0.40 mg·kg-1 in Liangshuijing Colliery and 0.47 mg·kg-1 in Sidaogou Colliery;（3）The values of（the comprehensive pollution degree） were 10.11 in Liangshuijing Colliery and 11.39 in Sidaogou Colliery respectively, indicating the comprehensive pollution degree was in middle-grade level. The single pollution index for different heavy metals had the following rule：Cd＞Zn＞Cu＞Pb＞Cr, and the corresponding value for cadmium was 5.43, indicating cadmium pollution was relatively serious in the soils of two collieries;（4）The total potential ecological risk factors varied in the range of 104.83~144.75, with mean values of 115.51 in Liangshuijing Colliery and 133.53 in Sidaogou Colliery, respectively, indicating the risk grade was in relatively low level. From the analysis of the single heavy metal element, the cadmium had the highest contribution to the potential ecological risk. This study will contribute new information about the potential pollution risk of soil heavy metals in Shenmu Mining Area, and it is predictable that those results could be helpful to protection of soils surrounding the collieries. |
