METHOD FOR PREPARING DEIONIZED WATER

摘要

PROBLEM TO BE SOLVED: To provide a method for operating an electric deionized water forming apparatus which prevents the formation of scale from hardness components. SOLUTION: This method for preparing the deionized water comprises a step of subjecting water to be treated which contains the hardness components to a deionization treatment by using the electric deionized water forming apparatus. The deionized water forming apparatus is formed by alternately disposing cation exchange membranes and anion exchange membranes between an anode chamber and a cathode chamber, alternately forming desalting chambers and thickening chambers between both of these membranes and packing ion exchangers which consist of a cation exchanger and anion exchanger into the desalting chambers. A ratio of the exchange capacity of the anion exchanger to the total ion exchange capacity of the cation exchanger and the anion exchanger combined is adjusted to≥0.5. COPYRIGHT: (C)2004,JPO