Study On Solute Transport Simulation And Groundwater Pollution Restoration Around Tailings Ponds In Arid Area

In recent years,China's mining scale of heavy metal minerals is increasing,and the number of mining is also increasing.The safety hidden danger and the influence to the environment are also rising day by day.Especially in the process of ore mining and tailings storage,the leachate is easily infiltrated into the ground without perfect anti-seepage measures,which has a huge impact on the groundwater environment in the mining area and surrounding areas.The study on the basis of field reconnaissance,sampling tests and the method of numerical model to construct the groundwater chemical environment in the studied area,and carried on the detailed study of groundwater flow field and field,and according to current situation of the current pollution of groundwater in the study area is proposed effective repair plan,a drought happened in tail mine groundwater pollution repair work provides the reference.The research results obtained in this study are as follows:1.The concentration of sulfuric acid ions and COD in the groundwater downstream of the tailings pond in the research area exceeds the groundwater quality standard of class III,and the concentration of the main solute in the water samples on both sides of the tailings pond is relatively close.Combined with the tracer test made before,it is proved that there is leakage in the tailings pond,which has a certain impact on the groundwater downstream.2.In a weakly alkaline environment,MoS₂ in the surrounding rock of the groundwater and in the tailings reservoir precipitates a large amount of SO₄^2-into the water under oxidation,and some molybdenum ions are adsorbed due to the presence of organic matter and iron-manganese minerals in the water,resulting in The phenomenon of excessive SO₄^2-concentration in groundwater in the study area is serious.3.The use of groundwater system simulation software GMS to tailings downstream sulfuric acid root ion in the groundwater was simulated with COD diffusion,it can be seen along the valleys in the main solute leakage rate under the direction to nearly 1400 m downstream has spread,affecting range has reached about270000 m2,and still spread in the downstream,and the diffusion area will continue to grow.4.Each pollution repair plan to make use of GMS software numerical simulation,the results show that lay in the valleys of pumping Wells,through continuous pumping can make pumping well formed near the small landing funnel of groundwater,can effectively control and reduce the solute influence scope expands,stop the spread of the upstream to the downstream of the solute,can achieve the aim of repair of the tailings downstream groundwater system.Plan 4 has the most obvious effect,respectively controlling the exceeded concentration of sulfate ion and COD within 47 meters and 95 meters downstream of the pumping well.