Study on Heavy Metal Migration and Optimal Allocation of Water Resources in Tailing Pond

Based on the potential threat of heavy metal pollution from a metal tailings pond in Tongling, Anhui Province to the mining area and the surrounding underground aquifer, the leaching test analysis of soil samples, the modeling of water quality and the prediction of groundwater level were carried out. The optimal allocation scheme of water resources was proposed finally. The results showed that the leaching concentration of major heavy metal elements in the soil tended to increase with the decrease of pH value or the increase of Ca²⁺ concentration, while Pb elements could not be leached out. By comparing with the local background value, the leaching toxicity of heavy metal elements in the mining area was relatively low. By simulating the underground flow through the MODFLOW module, it can be concluded that it takes about 63.5 years for the dynamic balance of 80 m level to be reached after the mine is stopped discharging. The transport of shallow groundwater to the west and deep groundwater to the south and east can be obtained by simulating solute transport through MT3DMS module. Based on the above research, the optimal allocation of mine water and artificial lake water was carried out, which provided scientific basis for the utilization of water resources in Tongling Mining area and reference value for other similar mining areas.