Mass transfer modeling of desalination through an electrodialysis cell

The aim of this study was to develop a mass transfer model for the prediction of ion transport through electrodialysis cells. A two-dimensional model of stationary and isothermal transfer of a strong binary electrolyte in a rectangular electrodialysis desalination cell was developed. The model considers concentration polarization phenomenon to study its influence on the ion separation. The developed model is a combination of two comprehensive models, i.e., three-layer model and convection-diffusion model. The boundary value problems included Navier-Stokes, continuity, and steady state Nernst-Plank equations. The set of equations with well-defined conditions was solved by the finite element numerical method. The model's equations were numerically solved using CFD techniques in three sub-domains of dilute, concentrate cells and membranes. This model is capable of predicting the local concentration and flux of ions, electrolyte potential and velocity distribution in the cells.