Study On Environmental Assessment Of Water And Soil In Rare Earth Mining Area In Southern Jiangxi

Under the background of resource exploration and environmental protection,which are steadily advancing steadily,research on the environmental quality and ecological risk assessment of mining areas has become a research hotspot in recent years.Study area is a typical enriched region of ion-adsorbed rare earth resources in southern China.In this paper,the two main environmental media,surface water and soil,which are typical ion-adsorption rare earth mines in Jiangnan,Jiangxi,are used as research objects.The environmental geochemistry,environmental science and engineering,ecology,etc.are assigned to the surface water and heavy metals in the area.A detailed study of the storage status,migration ability and biological effectiveness has been carried out,and some understanding has been obtained,mainly including:1.From the perspective of environmental geochemistry,systematic sampling and analysis of three different types of rare earth mines,light,medium and heavy,were carried out at intervals of 5 to 6 years.With the help of a large number of measured data and the application of comprehensive analysis methods,the ions were explored.The enrichment level of harmful elements in the water body and soil of the adsorbed rare earth mining area has analyzed the geochemical characteristics and environmental behavior of heavy metal elements in the water-soil circulation system.The quality of the water body at the sampling point far away from the mine area is good,which meets the water quality standard of Class I.The sampling points where Cd,Pb,Cu,and Zn exceed the standard and are polluted are mainly concentrated in the discharge water of rare earth mines,upstream and downstream of rare earth separation plants,and near mine tributaries.The average contents of Cd and Pb in the rice soil samples are 1.72 times and 2.14 times of the background value respectively;the average value of the soil Cd in the farmland along the river downstream of the mine in the watershed and the average value of the Pb in the farmland near the tailings reservoir are the soil background values 2.33 times and 3.06 times,the Cd and Pb contents of 22.7% samples exceeded the risk screening value.2.The article studied the content of heavy metals in soil samples,spatial distribution,form characteristics and factors.The heavy metals in the soil in the study area mainly exist in residual state,accounting for 65.5% of the total.The proportion of exchangeable states is second only to residual states,constitute 47.1% and 13.5% of contents,respectively.On the basis of heavy metal speciation analysis,geoaccumulation index method,potential ecological risk index and RAC index method were used to discuss the ecological risk of heavy metals in surface rice soil.The evaluation results of the geoaccumulation index and potential ecological risk show that the accumulation degree and ecological risk level of Cd and Pb are higher,and Co,Ni,Cu,and Zn are lower;the results of the RAC risk evaluation show that the ecological risk of Cd is higher,and Co,Zn,Pb is medium,and Cu and Ni are low.The evaluation results of the three methods all indicate that the Cd in the rice soil in the study area has a higher degree of accumulation and migration activity,and a higher ecological risk.3.The research results will provide a scientific basis for identifying the potential environmental risks of farmland soil around rare earth mines,and proposing effective mitigation,emergency and preventive measures.From the perspective of economic and social sustainability,it provides data support for the local government and relevant departments to objectively verify the cost of the mining environment and take timely control measures for the development of mineral resources.