Study on migration characteristics of pollutants in groundwater at a proposed hazardous waste landfill

Objective: The paper aims to analyze the hydrogeological conditions of a proposed hazardous waste landfill and the migration characteristics of lead, zinc, and nickel in fractured aquifers and porous aquifers under accident conditions and provide a reference for the influence of the proposed landfill on groundwater. Method: In this study, based on a 1:50000 regional hydrogeological survey and 1:2000 site hydrogeological mapping, the hydrogeological conceptual model was established. Finite difference software GMS was used to analyze the migration characteristics. Results: The study demonstrated that when the pollutants in the hazardous waste landfill leaked, they migrated from northeast to southwest along the gully. The pollutants in the porous aquifer migrated quickly, and the polluted area expanded rapidly from point to surface. The pollutants migration in fractured aquifers was slow, and the groundwater quality was deteriorating continuously. During the simulation period, the pollutants of lead, zinc and nickel all polluted the aquifer. Among them, the lead pollution range w reported to be the largest, with an exceeding distance of 216.7m; the zinc pollution range was the smallest, with an exceeding distance of 33.3m, and the exceeding distance of nickel was 165.1m. Conclusion: In order to ensure the safety of the groundwater environment in the simulated area, the impervious treatment must be carried out according to the requirements of the proposed hazardous waste landfill. Meantime, an emergency plan should be formulated.