Analysis and validation of the hydrodynamics of an electrodialysis cell using computational fluid dynamics

Due to the shortage of drinking water and the deterioration in its quality several processes have been developed to remove the ions and impurities contained. A technology used for the ions removal is the electrodialysis, which uses an electric field gradient and ion-exchange membranes to promote the movement of ions from treated water to a suitable compartment. Studies carried out using this technology have shown the influence of the hydrodynamic regime on the efficiency, mass transfer rate on the process and its influence on the concentration polarization. Using the finite element method, this work describes the hydrodynamic behavior and mass transfer in a filter press type electrodialysis reactor using computational fluid dynamics and experimental validation of the results obtained with CFD. The theoretical results show a good correlation with those obtained experimentally for hydrodynamics, from which the validation of the mass transfer and the distribution of potential on the electrodes and the solution is possible. A second validation is made by comparing theoretical and experimental mass transfer coefficients obtaining a maximum error of 16%. (C) 2017 Elsevier B.V. All rights reserved.