Assessment Of The Pollution And Ecological Risk Of Soil Heavy Metals In The Wutai Mountain Iron Mining Area

With the rapid development of China's economy,the relationship between people and the environment has become more and more tense.The development of industrial and mining enterprises has created a series of environmental pollution problems.Waste generated will be transported in the water stream,and atmospheric deposition will be attached to the surface.Soil will become pollutants major recipients,resulting in worse and worse soil environmental quality.In particular,the problem of heavy metal pollution in the soil caused by the mining process was most serious.If reasonable and effective control and treatment cannot be carried out with,it will pose a serious threat to human health and the development of the mining industry.Wutai Mountain Area,as an important energy extraction base in Shanxi Province,contains abundant iron ore and gold resources,as well as many associated minerals.With the mining of minerals,a large amount of tailings,slag,and acidic wastewater will accumulate on the surface,and heavy metals will leach into the soil as the surface rivers infiltrate,causing an enrichment of elemental contents in the soils of Wutai Mountain.It was a great significance to studying on the enrichment characteristics,spatial distribution characteristics,pollution status and potential ecological risks of heavy metals in the soil for rational use of land and protect the ecological environment in Wutai Mountainous Area.In this paper,the area where iron ore was more densely distributed in Wutaishan mountainous area was studied,and the area was classified according to the mining intensity of mineral resources: the northern mountainous area,the top of mountain,and the southern drainage area.The plum-shaped point method were used to collect the samples and the GPS positioning method was used to collect the above soil separately.The soil pH value was analyzed,the test analysis of the five elements was mainly using the time-saving and accurate inductively coupled plasma mass spectrometer analysis.The general situation of heavy metalcontent in major soils was analyzed using mathematical statistics methods.The software ArcGIS was also applied to conduct spatial interpolation analysis,and the correlation and principal component analysis methods were used to analyze the sources of heavy metals in the soil.The research shows that:(1)The degree of enrichment of the five heavy metal elements:Hg>As>Cd>Pb>Cr.The variation of Cr in Wutai Mountain North was larger,while on the top of the platform and the southern slope was smaller.The degree of variation of Cd,Pb,As,and Hg in the whole area was relatively large,which was strongly influenced by mining activities in the mining area;(2)The spatial distribution characteristics of heavy metal Cd and As have a certain similarity,they were annular distribution,and gradually increase from the middle to the periphery;the spatial distribution of Cr was high and low on both sides.The highest values were located in the Qingyang River in the east and the Yukou River in the west;the spatial distribution of Pb was low on both sides of the middle high,and the Yangyang River in the central and northern regions was the most serious;the overall spatial distribution of Hg was discontinuity,decreasing from north to south,and the northeastern region was the most serious;(3)The correlation and principal component analysis showed that the four elements of Cd,Pb,As,and Hg were highly related,and had a higher contribution to the first principal component,representing the source of mining pollution,while the correlation between Cr and other elements was relatively small,and it has a higher contribution rate to the second principal component,which was mainly derived from the geochemical background value and was a natural source;(4)From the single-factor pollution index,the Nemerow comprehensive pollution index,the geoaccumulation index,and the potential ecological hazard index,the heavy metal element Hg pollution was the most serious,decreasing from north to south;In Wutai Mountain North the pollution of heavy metal elements was serious and the ecological risk was serious.The concentration was mainly concentrated in the Yangyan River,Qingyang River and Qiaokou River,while the pollution and ecological risk of the southern slope and the platform top were relatively small.