Characteristic Evaluation For Soil Heavy Metal Pollution At Xujiping Mining Area Of Zhongdian City In Yunnan

With the development of People's mining activities, environment become a focus problem gradually, especially the heavy metal pollution problem in mine soil.The Heavy metal pollution has a directly or indirectly harm to the ecological environment and human health. Therefore, the quality of soil environment in the mining area and surrounding area is an urgent and important research topic.The article studys the heavy metal pollution condition taken place in Xuejiping mining area in Zhongdian city of Yunnan province.Through field investigation and analysis of soil samples, obtain a large amount of experimental data, then analyzes the statistical relationship between heavy metal elements and the pollution circumstance in the Xuejiping mining area,starting from the heavy metal pollution problems existed. Meanwhile,Use the index of the single Pollution index method, Nemerow index method and the Geo-accumulation index method and the potential ecological risk index method to evaluate contaminate degree and the heavy metalecological impacts level in mining area and provide the scientific theory basic for heavy metal pollution control in mining area. The main conclusions are as follows:(1) The total heavy metal concentrations were 3.95~45.6 mg.kg-1 for As, 0.05~1.04 mg.kg-1 for Cd, 33.2~695 mg.kg-1 for Cr, 23.6~2390 mg.kg-1 for Cu, 16.1~1504 mg.kg-1 for Pb, 35.6~252 mg.kg-1 for Zn, 0.018~0.117 mg.kg-1 for Hg.The average contents of elements except Cd?Hg are well above the background values of the Yunnan area and have high variations which shows that contents of As?Pb?Cu?Zn?Cr in soils have been affected by the impact of human activities.(2) Through the single Pollution index, the Nemerow index and the Geo-accumulation index and the potential ecological risk index system, heavy metal pollution levels and the risk of pollution in mining area of Zhongdian city in Yunnan of lead and the results indicates:Pollution index, the Nemerow index and the Geo-accumulation index were used to assess heavy metal contamination. Pi indicated that mine soils were not polluted by Cd?Hg, but slightly polluted by As?Zn and seriously polluted by Cu?Pb?Cr; Ni indicated that mine soils As?Cr?Cu?Pb is serious pollution, Cd?Zn is in the state of medium-contamination, Hg is slightly polluted;All I-geos showed that the pollution level of 7 kinds of heavy metals in various heavy metals all point average value as the basis, the study area of soil pollution level for each element sort. The rank(frome high to low) of the heavy metals in soils is Cu> Pb > Cr> As > Zn> Cd >Hg. All the sampling points in 4 points to reach 6, which is highly polluted, which accounted for 2 of Cu pollution point, higher values of Cu and Pb.When Ei was concerned, the results showed that the rank(frome strong to weak) of single metal element risk of potential ecological harm degree is Cu > Pb > Hg > Cd > As > Cr >Zn. The ecological risk of Cu is more prominent than others', and belongs to medium ecological risk level.Those of other heavy metal elements,such as Zn?Cd?Cr?Pb?Hg and As are at low level potential Ecological risk.Comprehensive potential ecological risk index RI display that the ecological risk level in Xuejiping mine achieve medium above.On the whole, the pollution pattern of the studied heavy metals were consistent assessed with the four methods, but variations existed.(3) In general, the pollution characteristic and the elements of heavy metal contamination were corresponding with the concentrations of Xuejiping mining area.Therefore, in the choice of reclamation method should suit one's measures to local conditions, according to the level of local soil heavy metal, choose the appropriate mode.In the paper, introduction of remediation technologies for heavy metal polluted soils such as physico-chemical remediation, phytoremediation, bioremediation and animal remediation.Should be from the source of governance, increase the ecological restoration of vegetation area. In terms of repair, Planted in contaminated soil Cu, Pb, Cr, As absorbency, resistance to strong plants, harvested stems and leaves, ground handling.By continuing cultivation of this plant, the leave of content in Cu, Pu, Cr, As can be reduced to the safe.