Performance assessment of electrodeionization cell with different inter-membrane spacing and operating conditions

Electrodeionization (EDI) is a separation method that combines electrodialysis and ion-exchange. The continual electrical regeneration of the ion-exchange resin is the main advantage of this resulting hybrid process. The purpose of this study is to see how the inter-membrane spacing (resin bed thickness) affects EDI performance. For this purpose, resin beds thicknesses of 2, 4 and 6 mm were tested by varying operating conditions and the efficiency of the process was expressed in terms of mass transfer flux (J), current efficiency (Ce), removal efficiency (R), power consumption (P) and by the comparison of I-V curves. Our research indicated that the choice of thickness depends mainly on the electrical and hydrodynamic conditions used. Furthermore, an impressive empirical equation describing EDI efficiency as a function of flow rate and cell thickness was established.