WASHING PROCESS AND WASHING UNIT

摘要

Materials to be washed are subjected to washing, while softening a washing water containing at least one of carbonate and bicarbonate ions and an alkali metal ion. The washing water before softening is prepared by the electrolysis of an aqueous sodium hydrogencarbonate solution and has a pH of 9.5 or more and an electric conductivity of 150 mS/m or more. The softened washing water has a total hardness of 40 ppm or less.