Demineralization of a solution containing aniline and sulfuric acid was studied at different voltages on the electrodialyzer with heterogeneous anion-exchange membranes MA-41 and perfluorinated homogeneous cation-exchange membranes MF-4SK. The main mass transfer characteristics of the process were evaluated. The limiting current density was evaluated for the cation- and anion-exchange membrane. The limiting current density on the anion-exchange membrane was reached much earlier than on the cation-exchange membrane. Electrodialysis was found to be most effective at voltages of up to 6 V in a pair chamber.