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. (C) 2014 Published by Elsevier B.V.