Study On Groundwater Pollution Model And Evaluation Methods In Closed Open-pit Mine

The risk and hidden danger of groundwater pollution around closed open-pit mine have become increasingly prominent,while the systematic research on the model and evaluation method has rarely been carried out.Based on the closed Fushun West Open-pit Mine,the paper researched the groundwater pollution model and comprehensive evaluation method of groundwater pollution by means of consulting data,field investigation test,numerical simulation analysis and so on.Firstly,the geological and hydrogeological conditions of the closed Fushun West Open-pit Mine were analyzed,and the characteristics of the groundwater dynamic and chemical fields were studied by combining on-site investigation and sampling experiments.The result proved that the main source of pollution is the pit water contaminated by water rock interaction.The Groundwater pollution model of closed open-pit mine is analyzed from three aspects of pollution sources,pollution channels and pollution receptors.Secondly,the groundwater flow model and solute transport model are established to simulate the rebound of mine water,the characteristics and the direction of groundwater flow field,the range and concentration distribution of solute transport.The results indicated that the final rebound water level of the open-pit will reach to the Quaternary aquifer.After the groundwater system reaches dynamic equilibrium,it will migrate towards the northwest direction,where the Hunhe River in the northern will be affected.The simulation results provide a reference basis for optimizing evaluation methods and verifying their effectiveness.Finally,the influencing factors of groundwater pollution in closed open-pit mine are analyzed,and 4 criteria layer indexes and 15 target layer indexes are determined.The analytic hierarchy process is used to determine the index weight,and the comprehensive evaluation method of groundwater pollution in closed pit open pit mine is established.The accuracy and reliability of the evaluation method have been verified through field investigation test.