摘要 |
1,176,982. Ion-exchange. ROHM & HAAS CO. 1 March, 1967 [9 March, 1966], No. 9637/67. Heading B1J. Anions are removed from liquids by passing the liquid downwardly through a scavenging layer of weak base resin in the free base form followed by a layer of strong base resin in the hydroxide form which is of greater density and different particle size. The resins are hydraulic classified, backwashed and partially mixed, regenerated with a basic medium and backwashed to stratify them into the treatment layers. |