Study On Geoelectrical Response Characteristics Of Landfill Leakage

The landfill may cause leakage of liquid pollutants due to the damage of the antiseepage layer,pollute the downstream groundwater quality,and affect the living water safety of the surrounding residents.Monitoring the movement of pollutants in the landfills and surrounding groundwater can detect leakage in time and provide effective hydrogeological data for timely treatment.In this paper,theoretical research,numerical simulation and physical experiment methods are used to study the migration law of the landfill seepage fluid and its geoelectrical response characteristics.First,based on the law of the migration and diffusion of the leakage liquid in the landfill and the monitoring technology of the direct current method,the basic equations for the migration of the leakage liquid along with the groundwater are established;using the Archie formula as a bridge,the resistivity and solution concentration of the aqueous medium are established The conversion relationship between them provides a theoretical basis for monitoring the movement of pollutants by the direct current method.Secondly,establish a hydrogeological model for numerical simulation and compare the effects of different effective porosity,different dispersion and replenishment strength on the migration of leakage fluid.The results show that the increase in effective porosity and dispersion will cause the horizontal migration of pollutants When the speed is reduced,the polluted area is reduced;while the increase in the replenishment strength will increase the horizontal migration speed of the leakage fluid and the polluted area.After that,the three-dimensional concentration data obtained by the numerical calculation is converted into three-dimensional resistivity data,which is used as the basis of the resistivity model,and the computer-based forward calculation is used to obtain the three-dimensional apparent resistivity monitoring data.The results show that the concentration distribution of the leakage fluid at the same time and The apparent resistivity distribution has a good correspondence,so the DC method can effectively monitor the migration of leakage fluid with groundwater.The leakage liquid under different replenishment strengths is compared,and the results show that the DC method can distinguish the different replenishment strengths of the leakage liquids.Finally,the physical model experiment method was used to simulate the movement of the leakage fluid in the point-like leakage with groundwater,and it was monitored in real time using a three-dimensional parallel electrical method instrument.The experimental results show that the apparent resistivity changes with the change of concentration,the change law is basically consistent with the pollutant migration law,which further verifies that the direct current method for monitoring the leakage of landfills with the groundwater migration process has a good monitoring effect.