| Abstrakt: |
In this study, zeolite and bentonite were used as the base materials to prepare barrier. Through mechanics experiment, penetration experiment, microscopic characterization, adsorption experiment, centrifuge model experiment and numerical simulation experiment, the control effect of barrier on ammonia nitrogen pollution in manganese slag storage yard was discussed. The results showed that the optimal mass ratio of zeolite and bentonite was 3:2, and the mass of cement accounted for 50% of the mass ratio of the whole system. The addition of zeolite improved the anti-penetrability performance and mechanical properties of the barrier material, the minimum hydraulic conductivity reached 2.049x10-10 m/s, and the maximum compressive strength reached 3.36 MPa. The zeolite made the internal structure of the barrier material became uniform and dense, which significantly improved the adsorption capacity of the barrier material to ammonia nitrogen. The adsorption process of ammonia nitrogen by the barrier material was more consistent with the quasi-second-order kinetic model and the Freundlich model, and the adsorption process was endothermic. With the penetration of ammonia nitrogen solution, the hydraulic conductivity of barrier material gradually decreased and became stable. Visual MODFLOW numerical model was used to simulate the process of ammonia nitrogen migration in groundwater, and the barrier was still not penetrated after 5 000 d. The zeolite-bentonite barrier showed excellent effect in preventing and controlling ammonia nitrogen pollution in manganese slag yard. [ABSTRACT FROM AUTHOR] |
