| In recent years,China has been focusing on economic construction.In the process of development,the demand for mineral resources has increased rapidly,which makes the mining industry develop vigorously.However,due to the rough development in the early stage of the industry and the lack of reasonable management standards,a large number of tailings formed by the accumulation of mineral wastes have emerged over time.The existence of tailings brings huge hidden danger to the surrounding environment.Under the effect of rainfall and other natural and human production activities,pollutant migration occurs,endangering the ecological environment.Especially for the underground water which is difficult to be detected at ordinary times,once the underground water as an important fresh water resource has pollution accidents,both the treatment difficulty and the treatment cost are far higher than the surface water.Therefore,it is necessary to protect and treat tailings in time to reduce the harm of tailings pollutants to groundwater.In order to provide a theoretical basis for regulating the production of mining industry,the migration and transformation of heavy metals and other pollutants in tailings into groundwater were studied.Antimony(Sb)is a new type of toxic pollutant,which is widespread in the environment.And antimony compounds have potential toxicity to human immune system,nervous system,gene and development.At present,the harm of antimony pollution to the environment is increasing gradually.In recent years,the relevant research results show that antimony pollution can be transferred through various ways to expand its pollution scope.Therefore,based on the harmfulness and mobility of antimony pollution,more attention should be paid to antimony pollution in water.China is the largest antimony producer in the world,and the residents in some areas depend on antimony industry.The long-term exploitation of antimony in this area has brought great pressure on the environment,including underground water.And some residents in the area use groundwater as domestic water for a long time.Influenced by the local antimony industry for many years,groundwater may already contain a lot of antimony pollution,which seriously threatens the daily life and health of local residents.Therefore,it is urgent to explore the current situation,source and migration of antimony pollution in groundwater in Xikuangshan area.Based on the previous research results and related field survey data,this study selected the typical antimony mine area water environment in Hunan Xikuangshan as the research object,and carried out the research on the source,migration and transformation of antimony in groundwater.The main contents are as follows:(1)This paper briefly introduces the harm of antimony pollution to human body and the pollution of waste tailings to the surrounding ecological environment after a large number of antimony ore mining in tin mine.According to the relevant data,there is a large amount of antimony in the environment around the tin mine.The average content of total sb in the water,soil and tailings of the mining area is 24.7μg/L,1315mg/kg and 3789mg/kg,respectively,which is much higher than the background value of the environment.Besides the average content of sb in fish,plant and vegetable was 59.8μg/kg,13.4mg/kg and14.1mg/kg respectively.(2)Based on the relevant literature and engineering data,this paper analyzes the meteorological,hydrological,geological,geomorphic and hydrogeological conditions in Xikuangshan area,and establishes the hydrogeological conceptual model of the study area through these data.At the same time,the principle of groundwater numerical simulation and the theoretical basis of the software are briefly introduced.Finally,the water flow model and solute transport model in Xikuangshan area are established by using Visual MODFLOW.(3)The solute transport model simulated by Visual MODFLOW predicted the transport of pollutants:(1)Pollutant migration direction: in addition to the influence of groundwater diffusion,it is also mainly affected by the direction of groundwater flow and runoff.Under the condition that convection is absolutely dominant,the pollutants in tailings reservoir mainly migrate to the north and the North West.(2)Pollutant diffusion range: the pollutant migration range in the tailings reservoir area is elliptical,and the pollution area gradually expands to the two-axis direction with the increase of simulation time.In the direction of groundwater flow,the range of pollutants in the downstream is large,while the range of pollutants in the upstream is small,and the range of pollutants migration in both sides of tailings pond is basically the same.(3)Vertical diffusion of pollutants: with the passage of time,groundwater gradually moves from the phreatic aquifer through the relative aquiclude to the confined aquifer,causing pollution to the deep groundwater.(4)In view of the current pollution situation,the anti-seepage treatment of tailings area is proposed,and the environmental protection degree of two different materials for groundwater is compared. |
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