DESIGN AND EFFECT EVALUATION OF THE BLOCKING WALL IN LANDFILL BASED ON VISUAL MODFLOW

In order to study the application effect of the blocking wall in a groundwater contaminated site, a city landfill in Sichuan province was taken an example and cadmium was selected as the target pollutant. The structure, location and scale of the blocking wall under specific conditions were designed through investigating hydrogeological conditions. The service life of the blocking wall was calculated by analytic method. MODFLOW and MT3D modules were used to simulate the distribution of cadmium pollution plume in groundwater before and after the blocking wall was set up, and the barrier effect was analyzed. The results showed that the blocking wall was a vertical barrier with funnel gate. The service life of the blocking wall was 12.51 years, under the condition that the thickness was set as 1 meter and Class Ⅲ groundwater quality standard was selected as the breakdown standard. In the contaminated field, cadmium would be absorbed by the blocking wall, and the hydraulic connection between the blocking wall and the downstream would be weakened, thus cadmium could be effectively blocked in groundwater.