Numerical Simulation of Ba2+ Transport in Vertical Plastic Concrete Cutoff Barrier

Taking the vertical plastic concrete cutoff barrier in the Guizhou Tianzhu Chemical Phase II landfill as the research object, the Hydrus-2D finite element simulation software was used to investigate the migration law of barium ion. Firstly, a plastic concrete soil column model was established, and the initial conditions of barium ion concentration, hydraulic head, and the boundary conditions of barium ion concentration were set. The software simulated the temporal and spatial variations of barium ion concentration in the vertical plastic concrete cutoff barrier, and evaluated the barrier effect of the vertical plastic concrete cutoff barrier on barium ions. The study revealed the following: (1) The vertical plastic concrete cutoff barrier exhibits a good barrier effect on the migration of barium ions. (2) The fastest migration of barium ions in the vertical plastic concrete cutoff barrier occurs at a depth of 22 m from top to bottom, making it more prone to breakthrough by barium ions. (3) For safety reasons, a barium ion concentration of 4 mg/L is recommended as the breakthrough criterion in the engineering project.