Simulation on forecast and control for groundwater contamination of hazardous waste landfill

Abstract

The groundwater flow and solute transport models were established by Visual Modflow, which was used to forecast the transport process of Cr6+ in groundwater and simulate the effects of three control measures of contaminants transport after percolation solution leakage happened in the impermeable layer of the landfill. The results showed that the contamination plume of Cr6+ would reach the pool’s boundary in 10 years, and the distance of contamination transport was 1,450 m. However, the contamination plume will not be obviously expanded between 10 and 20 years. While the ground was covered by hardened concrete, the contamination plume would not reach the pool’s boundary in 20 years. When the leakage-proof barrier was set in the bottom of an unconfined aquifer, the concentration of Cr6+ was higher than that of the leakage-proof barrier unset, but the result was opposite when setting the leakage-proof barrier in the bottom of confined aquifer. The range of the contamination plume was effectively controlled by setting drainage ditches in which water discharge was 2,298.05 m3 d−1, which produced monitoring wells which are not contaminated in 20 years. In sum, combining ground hardening with drainage ditches could produce the best effect in controlling contaminants diffusion, and meanwhile, the drainage ditches daily discharge was reduced to 1,710.19 m3 d−1.