Study And Forecast On Groundwater Pollution In Dawukou Landfill Of Shizuishan

Landfill leachate is organic wastewater with high concentration of complex component. Anti-seepage measures were taken in most landfill. However, groundwater would be polluted when the anti-seepage measures cannot work well or damaged. The pollution may last decades even hundreds of year. The recovery of environment is very difficult and the pollution has a negative effect on human life. Therefore, research and simulation of shallow groundwater pollution caused by landfill is very important, which has a great significance on preventing and controlling pollution and protect human health who live nearby.Based on the sufficient study of regional geological and hydrogeological conditions, a series of work was carried on, including collection of data, environmental geological survey, water level monitoring, sampling and analysis, hydrologic computation, water quality evaluation, health risk assessment, numerical simulation of groundwater and so on. The aquifer structure, recharge, flow and discharge of groundwater, and current condition of water environment were investigated in the study area around the Dawukou landfill of Shizuishan. On the basis of prior work, groundwater flow model and MT3 DMS solute transport model was established by Visual Modflow. After identifying and verifying the two-dimensional groundwater flow model till satisfactory, the migration regularity and tendency of NH3-N were simulated followed by selecting NH3-N as characteristic factor which exceeds standard most. The results show that NH3-N in the horizontal direction is mainly migrating to the northwest. In current situation if the landfill leachate leak for 18 years. After 18 years the center concentration of NH3-N reaches the maximum 500mg/L. Then the concentration decrease gradually,50 years later the center concentration of NH3-N drop to 80mg/L; If the measures are taken to prevent current leaking effectively, 18 years later the center concentration of NH3-N dropped to 80mg/L, 50 years later the center concentration of NH3-N drop to 25mg/L. Due to the flat ground, the groundwater moves very slow. The current pollution has not spread out of the landfill, after 50 years the pollution transport 490 meters only. The pollution is still manageable. It has little effect on the people who live far away from the landfill. The results of study are bases for groundwater protection and leachate treatment of Dawukou landfill.