| 摘要 |
<p>1432020 Regeneration of ion-exchangers ILLINOIS WATER TREATMENT CO 15 May 1973 [15 May 1972] 23129/73 Heading B1J [Also in Division C7] Spent regenerating solution for reuse in an ion exchange system having at least one ion exchanger is recovered by removing undesirable contaminants therefrom by precipitation, and converting it by electrodialysis to provide regenerating solution for regenerating the ion exchanger of the system. As shown, spent cation and/or anion exchange solution, e.g. obtained by rinsing with water via valves 10, 12 excess regenerating solutions from cation, anion and/or mixed bed exchangers 14, 16, 20 of a deionisation system and supplied via valves 22, 24, 65 to a holding tank 26, after concentration by use of a reverse osmosis unit 66 and precipitation of Ca and Mg by addition of line and/or soda ash followed by sodium phosphate via valve 36, is converted in electrodialysis cell 38 to regenerate acid e.g. HCl or H 2 SO 4 and/or alkali e.g. NaOH, being respectively fed to storage tanks 44, 48 via valves 42, 46 for reuse in the exchangers 14, 16, 20 via valves 50, 59 and 52, 63. The deionisation system may be used to treat raw or lime softened water or aqueous solutions of chemicals. NaCl or Na 2 SO 4 (or NaNO 3 ) may be added to the spent solution, after removal of contaminants, via valve 40.</p> |
