This study elucidates the technologies employed in membranebased water purification processes. The theoretical underpinnings of semipermeable membrane functionalities are expounded upon through the lens of Onsager’s reciprocal relations in non-equilibrium thermodynamics, delineating the fluxes and the driving forces that instigate them. Utilising a simplified Onsager matrix tailored for the ion-exchange membrane electrodialysis process, computational fluid dynamics (CFD) simulations were conducted. The computations presented herein depict the intricacies of both dialysis and electrodialysis in saline water solutions.