Numerical study on water and salt transport of electroosmosis in saline soil

Abstract

The study investigate water-salt interactions in porous media under electroosmosis. A theoretical model was developed to analyze the effect of salt precipitation on electrical conductivity, permeability, and volumetric capacitance, and to introduce precipitated salt parameters. The model describes water and salt transport through two mass conservation equations and incorporates the charge conservation equation. The model was validated through experiments of other scholars. The experimental results show that salt precipitation and dissolution play an important role in electrical conductivity since salt precipitation decreases drainage efficiency because it reduces hydraulic conductivity. The increase in conductivity of the solution is more important than the decrease in hydraulic conductivity due to salt precipitation because the higher the concentration of the solution, the higher its conductivity. The model suggests that salt plays an important role in electrical conductivity, as evidenced by the prominent nonlinear change in conductivity due to the inhomogeneous transport of solutes. The numerical model helps to predict water and salt transport in the electroosmosis of soils containing saline water.