Groundwater Pollution Research And Prevention Management Model In Baoping Copper Mining Area,Yunnan

With the development of society,the problem of groundwater pollution caused by human activities and industrial production is becoming more and more serious.How to control groundwater pollution and protect the groundwater environment has become an important topic in today's era.Baoping Copper Mine is located in the northwest of Yongsheng County,Lijiang City,Yunnan Province.The exposed strata are Permian Heinishao Formation sandstone,shale and basalt,Triassic Qingtianbao Formation sandstone and Beiya Formation limestone.The production process of copper ore is to produce sulfuric acid copper leaching solution by heaping sulfuric acid in the heap leaching field,and collect it to the collection pond.Once the leaching solution leaks in this process,it will pollute the surrounding groundwater environment.In order to protect the groundwater quality in the area,establish a model that conforms to the status of pollutant transport in Baoping Copper Mine site,and summarize the transport law of pollutants in aquifers of different media,on this basis,scientifically establish a groundwater pollution prevention and control management system.In this paper,through geological borehole exploration and massive collection of existing geological data in the study area,a comprehensive statistical study of the geological information in the study area,the establishment of a three-dimensional visualization solid model of the study area;through field geological survey combined with various hydrogeological tests,after summarizing the formation lithology,divided Out of the regional aquifer and find out the recharge,runoff,discharge conditions of groundwater and runoff direction of groundwater in the aquifer,synthesize these hydrogeological conditions and surface watershed,regional minimum discharge datum and other information to determine the hydrogeological unit range of the study area Build a conceptual model of the hydrogeological unit,establish a mathematical model through the conceptual model,use the MODFLOW module in the groundwater numerical simulation software GMS to simulate the natural groundwater flow field in the hydrogeological unit,and compare the flow field model with the actual measured water level on the drilling site to verify the flow field model;Through the water flow model,the MT3Ds module in the GMS software is used to establish the solute transport model,and the fitting verification is carried out to master the pollutant transport law.It is found that the pollutants in the polluted area are mainly vertical in the soil layer.Diffusion,and the rate of diffusion in the vertical direction Subject to a strong source of leakage effect when the vertical diffusion of pollutants to the underlying aquifer,mainly horizontal diffusion,and the diffusion rate is not affected by strong impact sources.On the basis of the above numerical model,a groundwater pollution prevention and control management model was established.According to the diffusion path of the leaked pollutants and the direction of pollutant migration,4emergency disposal wells were deployed downstream of the plant.The emergency disposal well can form a partial dropping funnel when pumping water,and the pollutants are drawn out by the emergency well to intercept the pollutants.The pumping volume and duration of emergency wells are based on the principle of optimal treatment results,considering the timeliness of pollutant treatment,and the objective function of the management model is determined to be the minimum pumping volume and the minimum residual pollutants.Run the management model under the constraints of water balance constraints,environmental constraints,etc.to obtain the optimal solution.After comparative analysis,the optimal disposal plan of the groundwater pollution prevention and control management model is:only the YJ1and YJ2 are activated under the first working condition to intercept the pollutants with the pumping volume of 150m~3/d and 100m~3/d,Continuous pumping for 3 days can effectively reduce the concentration of regional pollutants to the standard value;start YJ1,YJ2,YJ3,and YJ4 under the second working condition to intercept pollutants with pumping amounts of 350m~3/d,200m~3/d,300m~3/d,200m~3/d,and continue pumping for 9days can reached the standard value range.