Nitrate Transport Characteristics in the Soil and Groundwater

Nitrate as heat transfer and storage media can be widely used in solar thermal power, nuclear power, and other industrial engineering. If the leaked nitrate cannot be timely recovered, it will probably dissolve in the water, and then transport to the soil and groundwater. In this paper, a numerical model was built to simulate large-scale migration of nitrate in the soil and groundwater, and then the unsteady diffusion performance of nitrate in the groundwater was studied to prevent and reduce the environment pollution of leaked nitrate. The soil system was constructed by the loam and sand, and different groundwater levels and crossing flow rates were also considered. The results showed that the vertical nitrate diffusion range was mainly impacted by the groundwater depth and annual precipitation. As the groundwater depth was deeper or the local annual precipitation was larger, the nitrate pollution can permeate deeper. As the crossing velocity increased, the horizontal pollution range remarkably increased and the vertical pollution range decreased, and the saturated soil layer was more obviously influenced by the crossing flow.