Electrodialysis plant at Hatsushima

A commercial multistage batch system electrodialysis plant for desalination of brackish groundwater was installed at Hatsushima, Atami City in April 1973. The plant has three stages each of which is operated at a constant voltage. Each stage has a dialyzer which is provided with 150 pairs of ion exchange membranes having an effective area of 1 m² each. This plant is used for drinking water supply and has a capacity of 200 m³/day when the raw water has a saline concentration of 6,000 ppm TDS. The operation was very stable and easy, and it was possible to produce water of constant quality at all times regardless of fluctuations in the raw water concentration. The dialyzer was chemically cleaned for removal of deposits on membranes thereby reducing the maintenance cost by 62% without adversely influencing ion exchange membranes.