铁尾矿区不同复垦模式土壤环境质量评价

Soil Environmental Quality Evaluation of Different Reclamation Patterns in Iron Tailings Pond Area

以山西省运城市垣曲县泉子沟铁尾矿区为研究区,按一定比例在尾矿砂中添加土壤、菌糠共6种复垦模式,选用单因子污染指数法和内梅罗综合污染指数法,对复垦土壤中的Cd、Cr、Cu、As、Zn、Ni及Pb7种元素进行环境质量现状评价,并分析各复垦模式下土壤表层重金属含量变化特征。结果表明,纯尾矿砂中添加菌糠比添加土壤能更有效地降低Cd、As、Ni、Cr这4种元素含量,降低范围为0.07~33.77mg/kg,但对于Pb和Cu,施加土壤的改良效果更好;与纯尾矿砂相比,6种复垦模式土壤的Cu、Ni、Cr、Zn平均值降低了5.4%~64.5%;Ni、Cu、Zn的含量超过了毗邻区土壤背景值,除As外,其他6种重金属均超过了山西省土壤背景值,仅有Cu超过了国家评价标准,Cu的超标率最严重;单因子污染指数分析结果表明,除Cu外,其余6种元素均为轻微污染,其他元素无污染;内梅罗综合污染指数分析表明,6种复垦模式的土壤大部分属于尚清洁(警戒级)土壤,其中Cu含量高,分担率最大。

Taking Quanzigou iron tailings pond in Yuanqu county of Yuncheng city of Shanxi province as the study area,six reclamation patters by adding soil or spent mushroom residues to tailings sand according to a certain proportion,were carried out.The heavy metals of Cd,Cr,Cu,As,Zn,Ni and Pb in the soil of six reclamation patters were evaluated with the single factor index method and Nemerow multifactor index method,and the changes of heavy metal contents in the surface soil were also analyzed.The results showed that the contents of Cd,As,Ni,Cr in the tailings of adding soil were lower than that in adding spent mushroom residues,and the range of decrease was from 0.07 to 33.77 mg/kg.But for Pb and Cu,the amelioration effect of adding soil was better.Compared with pure tailings,the contents of Cu,Ni,Cr and Zn in the soils of the six reclamation patters averagely decreased by 5.4%-64.5%.The contents of Ni,Cu and Zn exceeded the background value of soil in the adjacent area,and the contents of six heavy metals except As exceeded the background value of soil in Shanxi province.Only the content of Cu exceeded the national evaluation criteria,indicating that the exceeding standard rate of Cu was the most serious one.The results of single factor polution index analysis showed that except for Cu,which was slightly polluted,the other six elements were non-polluting.The analysis of Nemerow multifactor index showed that most soil of the six reclaimed patters belonged to the level of clean(vigilant),resulting from the largest contribution rate Cu.