Electromigration of Nitrates in Soil

Abstract

Migration of chemicals in soils to surface or ground water has become a serious threat in many agricultural regions, with nitrates affecting the broadest area due to intensive fertilization and nitrate solubility. This project evaluated electroreclamation utilizing subsurface horizontal drainage tubing and parallel electrodes to concentrate and remove nitrates from soil. Nitrate concentration in saturated soil tended to increase from anode to cathode after the application of a small direct-current electrical field as the nitrate solution moved toward the cathode. When soil moisture content dropped below the saturation level, the nitrate began to migrate toward the anode. Research is recommended to evaluate the effect of a broader range of electrical parameters and analyze the feasibility of commercial application.