煤矿复垦区土壤重金属含量时空分布及富集特征研究

为研究煤矿复垦区土壤重金属污染的时空变化及富集特征，以安徽淮南市潘一矿复垦区土壤为例，在2008-2010年期间对复垦区土壤中Cu，Mn，Ni，Pb，Cd，Hg，As 七种重金属元素进行了测定，并利用Surfer8.0软件对重金属的水平分布特征进行可视化表达。采用富集因子法来判断土壤中重金属人为污染情况。结果表明：煤矸石充填复垦区土壤，随着覆土年限的增加，除Mn和As元素外，Cu，Ni，Pb，Cd和Hg这5种重金属元素含量均高于淮南市土壤背景值，并出现一定程度的累积；从表层土壤重金属元素的水平空间分布看，煤矸石山的堆积、淋溶和粉煤灰贮灰场的存在对周边土壤造成了一定程度和范围的重金属污染。复垦区土壤剖面上Cu，Ni，Pb，Cd元素含量呈现表层（0~20 cm）和底层（80~100 cm）含量高，中部（20~80 cm）含量低的分布规律。分析重金属元素的富集因子，表明复垦区土壤已经受到了煤矿开采和煤矸石充填活动的影响。其中Cu，Ni，Pb，Hg和Cd元素已经出现富集，并且Cu，Ni，Pb，Hg元素达到了轻微污染水平，Cd元素达到了显著污染水平。Mn和As元素主要来源于土壤母质，没有受到污染。

Characteristics of temporal spatial distribution and enrichment of heavy metals in coal mine reclaimed soil

In order to analyze the characteristics of temporal spatial distribution and enrichment of heavy metals in coal mine reclaimed soil，this study selected Panyi coal mine at Huainan in China as its study area.The contents of heavy metals Cu，Mn，Ni，Pb，Cd，Hg and As in reclaimed soils were measured and analyzed during year 2008—2010.The temporal spatial distributions of seven heavy metals contents were mapped using Surfer 8.0 software to provide a visual image of the spatial distribution of these heavy metals.In addition，enrichment factor was estimated to show the anthropogenic pollution of heavy metals from natural anomaly in reclaimed soils.The results show that in coal gangue reclaimed soil，with the age increase of covering soil，except Mn and As，the contents of Cu，Ni，Pb，Cd and Hg are higher than that in the background soil.There is a certain degree of heavy mental accumulation.As shown in the spatial distribution of heavy metals，because of the leaching of coal gangue hills and the existence of coal ash storage yard，the surrounding soil was polluted in some extend by heavy metals.The vertical distributions of heavy metal elements in the reclaimed soil vary with different contents，while the overall contents of Cu，Ni，Pb and Cd elements at the surface layer between the depth 0-20 cm and the bottom layer from 80 to 100 cm were remarkably higher than middle layers from 20 to 80 cm.The results show that the reclamation area soils have been affected by coal mining activities and coal gangue dumping through analyzing the enrichment factor.The Cu，Ni，Pb，Hg and Cd elements have been enriched，and the Cu，Ni，Pb and Hg elements reach light pollution levels，the Cd elements reaches a significant pollution level.The Mn and As elements mainly come from the original soil material in the reclaimed soils，and thus there is no pollution from Mn and As metals.