A Management Model For Groundwater Pollution Prevention And Control In Yunnan Wenshan Aluminum Plant

With the rapid development of the Chinese southwestern economy,the demand for electrolytic aluminum in various industries has increased year by year.Yunnan Wenshan Aluminum has invested in the Chinese“11th Five-Year Program”.The aluminum plant was built near the Jiama Village in the northwest direction of Wenshan City.The area is mainly Carboniferous,and the exposed lithology is limestone and dolomitic limestone.During the production and operation of the aluminum plant,the anti-seepage layer of the key anti-seepage area will be damaged or invalid.Once the pollutant leaks,it will seriously affect the regional karst groundwater,which threatens the water quality of the two drinking water spots in the Jiamaishi Village downstream of the plant.In order to protect the groundwater centralized water source downstream of the aluminum plant from pollution,and to effectively control and treat the pollutants leaking into the groundwater,it is of great practical significance to scientifically establish a groundwater pollution prevention and control management system downstream of the runoff zone of the plant.Therefore,based on a large collection of geological data from the study area,this study combines field geological survey,hydrogeological test,geophysical exploration,geological drilling and other technical methods to grasp the aquifer distribution,groundwater recharge and drainage conditions,and regional groundwater.Hydrogeological conditions such as runoff direction.The conceptual model of the study area is established by comprehensively analyzing regional hydrogeological conditions,and the boundary conditions of the conceptual model are elaborated to make the north side of the study area water-separated,and the south side is defined as the fixed water head boundary.Based on the conceptual model,a mathematical model is established.The natural flow field in the study area is simulated by the MODFLOW module in the groundwater numerical simulation software GMS,and the water flow model is fitted and verified by the actual observation of the water level.In order to explore the law of pollutant transport,the solute transport model is established on the basis of the water flow model,and then the numerical model is coupled with the optimized management model,and the optimized management model is solved by GMS.The management model sets up the pollution prevention and control emergency disposal well after analyzing the dispersion route and direction of the pollutants,and at the same time ensuring that the disposal well can form a local falling funnel and can effectively intercept the pollutants,taking into account the timeliness of the pollutant treatment,so that the total pumping volume The minimum objective function of the management model is to run the management model under the constraints of water equilibrium constraints and environmental constraints,and obtain the optimal solution.Through comprehensive comparative analysis,the optimal management plan for the control and control of groundwater dyeing by the established management model is:in the first working condition,only YJ1 and YJ2 are started to intercept pollutants with pumping capacity of 530m~3/d and 360m~3/d,respectively;In the second working condition,YJ1,YJ2,YJ3 and YJ4 were started and the pollutants were intercepted by the pumping amount of 450m~3/d,420m~3/d,360m~3/d and 330m~3/d.