Continuous dialysis of sulphuric acid in the presence of zinc sulphate

Transport of sulphuric acid in the presence of zinc sulphate through the anion-exchange membrane Neosepta-AFN (Astom Corporation, Japan) was studied in a two-compartment counter-current dialyzer with single passes at steady state. The following characteristics were used to characterize the dialysis process: recovery yield of acid, rejection coefficient of salt, and permeability coefficient of the membrane. In case of the H2SO4 + ZnSO4 mixture, permeability of the membrane was quantified by four phenomenological coefficients which are functions of acid and salt concentrations in the feed. They were determined by numerical integration of differential equations describing the concentration profiles of both components in both compartments, which was combined with an optimizing procedure.