Soil Heavy Metal Elements Content Characteristics And Pollution Evaluation In Changhua Lead-zinc Mine Tailings Wasteland Of Hainan

With the development of mining activities, environment become a focus problemgradually, especially the heavy metal pollution problem in mine soil. The Heavy metalpollution has become an important factor that destroy the quality of soil environment in themining area and surrounding area, Heavy metal pollution is harm to people’s safety of life andproperty directly or indirectly. In the process of mining and smelting, the tailings havebecome an important source of soil heavy metal pollution.In this research, I will start with the soil heavy metal pollution problems in miningactivity, the basic aim is to deal with soil heavy metal pollution in mining area. This essay isbased on lots of relevant documents and combined with soil and environmental geochemistry,My study object is lead-zinc mine tailings wasteland in HaiNan ChangHua, this essay isbased on the75samples through field survey and sampling，At first, I make indoor analysis ofsoil samples, obtain a large amount of experimental data, then reveal the content distributionof soil heavy metal elements. Meanwhile, Use the index of potential ecological risk method,single factor index evaluation method and Nemerow pollution index method and ndex ofgeo-accumulation to evaluate soil heavy metal pollution degree and pollution risk towasteland. The mainly conclusion as follows:(1) In the base of heavy metal content of Changhua lead-zinc mine wasteland，thecontent of Heavy metal element Cd, Cu, Pb, Zn is relatively higher and more than backgroundvalues of Hainan soil, it shows that those heavy metal elements are significantly rich andaffected by lead-zinc mine smelting seriously. But the heavy metal elements Cr, Ni, As arerelatively less.(2) From the level of distribution, from the entire study area, in the heavy metal content,the content of the tailings distribution is the highest, followed by the reclamation area, andfinally is the periphery area. The average concentration distribution of heavy metal elementsof Cd, Zn, As for the reclamation area are more than tailings area, tailings area are more thaneriphery area. The content distribution of heavy metal elements about Cr, Cu, Ni, Pb, tailingsarea reclamation area are more than periphery area. Compared to those, the heavy metalcontent of the peripheral area are lowest. From the vertical distribution, heavy metals in tailings area are mainly distributed in thesoil between60and100cm, the degree of enrichment Ⅲ and Ⅳ layer is higher. In addition tothe highest concentration of As element in the layer of Part I; the distribution of heavy metalsin the soil of the reclaimed area is relatively not regulate. The Cr, As elements are rich in thesurface, the Cu elements are rich in Part II, Ni and Zn are rich in Part III, Cd and Pb elementsgathered in the bottom.Peripheral area of heavy metals in soil of Ni are increased with depth,increments content, which reaches the highest value in the layer Ⅴ.Elements of Cd, Cu andPb reaches its maximum in the surface content, the enrichment level is the highest. Cr and Asin section Ⅳlayer enriched the highest degree, Zn in the III layer enriched in the highestdegree.(3) Through the potential ecological risk index, the single-factor pollution index andNemerow pollution index method and cumulative evaluation index system, heavy metalpollution levels and the risk of pollution in Hainan Changhua of lead and zinc waste soil, theresults showed that environmental quality in Hainan Changhua of lead and zinc waste soil isterrible, and heavy metal pollution is serious. In particular, the most serious level of pollutionis the tailings and reclamation area, the periphery region is not deep in degree, almost eachsampling place has a heavy metal pollution phenomenon. The results of three pollutionassessment methods for the calculation showed that Cd, Cu, Pb, Zn exist of the three studyareas are at a very high pollution degree, it is the major factor which caused pollution inChanghua lead and zinc waste, the content of four elements are unusually high, the potentialecological risk are high, so it need more attention; and other heavy metal elements such as As,Ni and Cr elements are almost not cause pollution.