Research On Pollution Assessment Of Heavy Metal To The Soil In Maanshan Key Mining Area

The mining of heavy metal mineral resources has greatly changed the original soilenvironmental structure and status. When the heavy metal content in the soil is more thansoil self-purification capacity, it will cause heavy metal pollution on the soil. The heavymetal pollution to the soil not only causes some serious harm to the ecologicalenvironment and human health, but also restricts the development of heavy metal mining.The assessment of heavy metal pollution in the soil is a necessary mean to understandthe soil pollution status, control and improve the soil environment. Therefore, the heavymetal pollution assessment in the mine soil is very essential.Maanshan city in Anhui province is not only one of the seven iron mining area inChina, and also contains a number of associated ore at the same time. The tailings, slag, andwaste water generated in the iron ore and other mineral which contain gold，copper andother elements has became the major source which create heavy metals pollution in theMaanshan mine soil. On the basis of the review a large number of literatures about theheavy metal pollution to the soil, This study analyzes the statistical relationship betweenheavy metal elements and the pollution circumstance in the Maanshan key miningarea,starting from the heavy metal pollution problems existed. In the article, the nemerowindex method, geoaccumulation index method and the grey clustering method are used toevaluate the heavy metal pollution levels in the soils. At the same time, the use of thepotential ecological risk assessment method evaluates the risk of the Maanshan key miningarea.Based on the descriptive statistical analysis of the content of heavy metal elements inMaanshan key mining area, the average content of Hg and Cu was three times more thanthe background value in Maanshan. The two elements has accumulated. In all themonitoring elements, the content of As, Pb, Cr in all sampling points were not to surpassthe second national standards. The other elments’ content is higher than two nationalstandards. It shows a certain pollution trend, in which the situation of Cu content exceededthe standard is most serious. In the eight heavy metal elements, the variability of Hg is thelargest. The turns of variation from large to small are Hg, Cu, Cd, Zn, Ni, Pb, Cr, As. Theresult of multivariate statistical analysis shows the four elements which are Cd、Cr、Ni、Zn are from the same source. They were form the ore smelting enterprises and some factories which provide smelting fuel around the mining areas. As and Cu came fromNanshan mine area. Pb and Hg may be from natural factors in the soil.In the paper, the evaluation factors of the grey clustering method are selected accordingto the assessment result of geoaccumulation index method. Combined evaluation results ofNemero index method, geoaccumulation index method and grey clustering method,wecan find the soil in Hengxing village of Jiangshan town, Shima villiage, Tao villiage andDutang villiage of Xiangshan town has been polluted lightly. Cu and Hg are the mainpollution factors, and the Cr element didn’t cause to pollute. Therefore, In Maanshan keymining area, the level of heavy metal pollution to the soil is not serious.The potential ecological risk assessment method shows Hg ecological risk is the mostserious, the second element is Cd. The other six heavy metals did not achieve a moderateecological risk level, so these elements’ ecological risk is low comparatively.Comprehensive potential ecological risk index RI display that the ecological risk level inHengxing villiage, Shima villiage, Tao villiage and Dutang villiage near Nanshan mineachieve medium above. As a whole, ecological risk degree in Maanshan key mining area isstrong, It need to be paid attention to.