US3565797A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and process for treating sewage
Assignee: RALPH R GRESHAM
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Filing: 1968-06-12
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Granted: 1971-02-23
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Expires: 1988-06-12
Abstract
Abstract APPARATUS AND PROCESS FOR THE TREATMENT OF SEWAGE BY OXIDATION AND BY CONTACTING SAID SEWAGE WITH LIVING FILAMENTOUS ALGAE AFFIXED TO A SUITABLE SUPPORTING FRAMEWORK. SEVERAL STAGES OF TREATMENT MAY BE USED, BUT A SINGLE STAGE OF TREATMENT THROUGH MOVING CONTACT OF THE SEWAGE WITH AN ALGAE BED OR SCREEN OF SUFFICIENT SIZE WILL PROVIDE COMPLETE OR ALMOST COMPLETE REMOVAL OF SUS- PENDED SOLIDS, AND THE BIOCHEMICAL OXYGEN DEMAND OF THE EFFLUENT WATER CAN BE REDUCED TO ACCEPTABLE LEVELS FOR DISPOSAL IN STREAMS AND LAKES.
Inventors
- 👤 Paul J Gresham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 22:33
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/08; C02F3/082; C02F3/32; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y02W10/30; Y02W10/37
Claims Analysis
Total Claims: 0
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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) | 1974-02-22 | 1974-08-24 | 1975-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-22 | 1978-08-24 | 1979-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-22 | 1982-08-24 | 1983-02-23 | $7700.00 | Window Closed / Lapsed |