The regeneration of acid and base from sodium sulphate by electrohydrolysis was investigated in two-compartment membrane electrolysis cells. Two types of cation-exchange membranes, perfluorinated Nafion(R) 117 and the Pall RI 010 were compared under similar operational conditions. An arrangement using an anion-exchange membrane (Pall R1030) in a two-compartment cell was also studied. The effect of flow rate, current density, initial salt concentration and temperature on the performance of each membrane is described. Results concerning current efficiencies, transport properties and achievable product concentrations are presented, The Pall R1010 gave higher current utilization and sodium hydroxide generation than the Nafion 117 membrane.