Effect of electrode area on demineralization performance and the distribution of current density in an industrial scale electrodialysis stack was studied. A segmented electrode was used for this purpose. Several combinations of active/inactive segments of the electrode were tested and results obtained were mutually compared. It was found that any reduction of the electrode area caused the demineralization performance to decline and generated extremely high local current densities at the edges of the electrode. The experimental results were qualitatively in correlation with a macrohomogeneous 2D model for computation of the distribution of electric potential, electrolyte concentration in the dilute and current density in the electrodialysis stack. (C) 2017 Elsevier B.V. All rights reserved.