| 摘要 |
505,186. Purifying water. I. G. FARBENINDUSTRIE AKT.-GES. Nov. 5, 1937, No. 30368. Convention date, Nov. 24, 1936. [Class 46] In the process of removing salts from water by successive passage through a hydrogen exchange material and a hydroxyl-exchange material, the hydroxyl-exchange material, after regeneration by treatment with alkali, is washed with water passed through from the hydrogen-exchange material towards the end of the period of use of the latter, which water will contain sodium ions but will be free from calcium ions. |
