US3554905A
Expired / Lapsed
US
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Process for treating water with a polyhalide resin using a semipermeable membrane barrier
Assignee: Dow Chemical Co
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Filing: 1969-04-01
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Granted: 1971-01-12
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Expires: 1989-04-01
Abstract
Abstract AN IMPROVED PROCESS FOR TREATING WATER WITH HALOGEN RELEASED BY AN ANION-EXCHANGE RESIN IN POLYHALIDE FORM IS OBTAINED BY USING A MEMBRANE PERMEABLE TO HALOGEN BUT ESSENTIALLY IMPERMEABLE TO WATER AND WATER-SOLUBLE ANIONS TO SEPARATE THE POLYHALIDE RESIN AND THE WATER BEING TREATED. SUCH A MEMBRANE REDUCES THE POLYHALIDE RESIN INSTABILITY ARISING FROM THE INFLUENCE OF WATER-SOLUBLE ANIONS AND ALKALINITY IN THE WATER SUPPLY. PARTICULARLY EFFECTIVE IN THIS PROCESS IS A POLYETHYLENE FILM PACKET OF A POLYBROMIDE RESIN.
Inventors
- 👤 John Place
- 👤 Robert D Goodenough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:21
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/72; C02F1/76; C02F1/766; B; B01; B01D; B01D61/00; B01D71/00; B01D71/06; B01D71/26; B01D71/261; B01J; B01J41/00; B01J41/04
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-01-11 | 1974-07-13 | 1975-01-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-01-11 | 1978-07-13 | 1979-01-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-01-11 | 1982-07-13 | 1983-01-12 | $7700.00 | Window Closed / Lapsed |