Present status of electrodialysis process in Japan

This paper describes the present activities of the electrodialysis process in Japan. The ion-exchange membranes and the electrodialyzers are supplied mostly by the three companies. The physical and chemical properties of the membrenes have good performance. The electrodialyzer units which have 50 to 1,800 pairs of 0.03 to 1.6 m² membranes are used for the desalination. Many commercial plants which have the capacities of 1 to 12,000 m³/day are in operation for the desalination of brackish water or sea water, and a few test plants have been operated in order to the desalination of municipal or industrial waste water for reuse.