DESALINATION PROCESS

• US 3,639,231 A
• Filed: 11/13/1970
• Issued: 02/01/1972
• Est. Priority Date: 11/13/1970
• Status: Expired due to Term

• Current Assignee: Sidney A. Bresler
• Original Assignee: Sidney A. Bresler
• Inventors: Bresler, Sidney A.
• Primary Examiner(s): Zaharna, Samin N.
• Application Number:
  US05/089,429
• Time in Patent Office: 445 Days
• Field of Search: 210/22,23,26,30,37,38,259,321
• US Class Current: 210/638
• CPC Class Codes: B01D 2311/04 Specific process operations in the feed stream; Feed pretreatment
• CPC Class Codes: B01D 2311/2623 Ion-Exchange
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: B01D 61/04 Feed pretreatment
• CPC Class Codes: B01J 49/00 Regeneration or reactivation of ion-exchangers; Apparatus therefor ion-exchange chromatography processes or apparatus B01D15/08
• CPC Class Codes: C02F 1/42 by ion-exchange ion-exchange in general B01J
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 2103/08 Seawater, e.g. for desalination
• CPC Class Codes: C02F 2303/16 Regeneration of sorbents, filters
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage
• CPC Class Codes: Y02A 20/131 Reverse-osmosis

Abstract

Brackish water is desalinated by contacting it with one or more ion exchange resins followed by reverse osmosis. Brine rejected in reverse osmosis treatment can be used to regenerate a used ion exchange resin.

Claims

2. The process for removing inorganic salts from an aqueous solution containing the same, which comprises:

a. contacting said solution with an ion exchange resin active at a pH of from about 5 to about 14, to remove ions present in said solution, b. contacting the solution obtained in (a) with an ion exchange resin active at a pH of from about 1 to about 14, to remove ions present in said last-mentioned solution, c. forcing the solution obtained in (b) through a reverse osmosis membrane which rejects and concentrates salts present in said solution, d. collecting an aqueous product having an inorganic salt content substantially less than said aqueous solution, and an inorganic salt product, and e. regenerating said ion exchange resin of (b) with said inorganic salt product collected in (d).

3. The process of claim 2, wherein the aqueous solution is a brackish water.

4. The process of claim 2, wherein the ion exchange resin of (a) is an acrylic acid resin having carboxylic acid groups.

5. The process of claim 2, wherein the ion exchange resin of (b) is a sodium sulfonate vinyl benzene.

6. The process of claim 2, wherein the membrane of (c) comprises cellulose acetate.

7. The process of claim 2, wherein the membrane of (c) comprises a nylon.

8. The process of claim 2, wherein the ion exchange resin of (a) is regenerated with the stream obtained by regenerating said ion exchange resin of (b) with said inorganic salt product.

9. The process of claim 2, wherein the ion exchange resin of (b) is a vinyl benzene containing a quaternary ammonium substituent.

10. The process for removing inorganic salts from an aqueous solution containing the same, which comprises:

a. contacting said solution with an ion exchange resin active at a pH of from about 5 to about 14, to remove ions present iN said solution, b. contacting the solution obtained in (a) with an ion exchange resin active at a pH of from about 1 to about 14, to remove ions present in said last-mentioned solution, c. forcing the solution obtained in (b) through a reverse osmosis membrane which rejects salts present in said solution, and d. collecting an aqueous product having an inorganic salt content substantially less than said aqueous solution, and an inorganic salt product.

11. The process of claim 1 wherein said inorganic salt product collected in (c) contains an acid component and wherein said ion exchange resin of (a) is regenerated with said acid component.

12. The process of claim 2 wherein said inorganic salt product collected in (d) contains an acid component and wherein said ion exchange resin of (b) is regenerated with said acid component.