Time dependence of transport number ratio during electrodialysis process

The transport number ratio between anion and chloride ion P(Cl)(a) was measured to discuss the anion permselectivity in an electrodialysis (ED). It was shown that P(Cl)(a) changed with the progress of ED. In this paper, a mechanism of anion permselectivity in ED was theoretically discussed with an equivalent circuit to find the reason why P(Cl)(a) changed with the progress of ED. It was found that P(Cl)(a) depended on the total electrolyte concentration of the diluted compartment C(B). Then, P(Cl)(a) changes with the progress of ED, since C(B) decreases with the progress of ED. In addition, the simulation of ED with the equivalent circuit was successfully performed using the electric resistances of the equivalent circuit obtained from the analysis of P(Cl)(a).