陕西某矿长期堆放的煤矸石对土壤的影响

Influence from Soil by the Coal Gangue Piled up for the Long-time of a Coal Mine in Shanxi Province

分析研究了陕西某矿长期堆放的煤矸石对周围土壤环境的影响。在煤矸石山周围土壤中重金属和主要成分具有如下空间分布特征:随着与煤矸石山距离的增大,表层土壤中Cu,Zn,Pb,Ni质量分数逐渐变小,As,Cd质量分数基本不变;在土壤垂向剖面中,Ni,Cu,Zn,Pb质量分数在表层至30cm内较大,且随着深度的增加逐渐减小,As,Mn质量分数变化不大。以背景值作为评价的标准值,采用单因子指数法和尼梅罗综合指数法对煤矸石山周围的土壤进行了污染评价,结果表明表层土壤和剖面50 cm深度内的土壤受到了轻微污染。通过与土壤环境质量标准(GB 15618—1995)中的二级标准(pH>7.5)对比,矸石山周围表层土壤和剖面土壤的重金属和主要成分质量分数符合二级土壤环境质量标准,但是表层土壤和剖面中部分土壤样品的污染指数大于1,说明污染物已经进入了煤矸石山周围的土壤,应注意防范。

In the study,we analyzed and studied the influence from soil by coal gangue piled up for long-time of a coal mine in Shanxi province.The heavy metals and the bases of soil around coal gangue had the following features of spatial distribution：the contents of Cu,Zn,Pb and Ni in soil decreased gradually with the distance to coal gangue increasing,the contents of As and Cd did not mainly change.In the vertical profile,the contents of Ni,Cu,Zn and Pb improved from the ground surface to 30 cm,and the content decreased with the depth.The content of As and Mn had a little variation.Background value as the standards values of pollution assessment,we made some evaluation for the soil around the coal gangue by the single index and Nemerow aggregative index.The results showed that the surface soil and in the 50 cm depth soil had been light polluted by coal gangue.Compared with secondary standard （pH 〉 7.5） of environmental quality standard for soils （GB 15618-1995）,the contents of heavy metals and the bases of surface soil and profile reached the requirement regulated of standard Ⅱ,but pollution index of parts of samples greater than 1,which showed that the contamination had already entered the soil around coal gangue,so we should pay attention to the prevention of further pollution.