US3640820A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sewage treatment process
Assignee: ChampionX LLC
•
Filing: 1971-01-11
•
Granted: 1972-02-08
•
Expires: 1991-01-11
Abstract
Abstract A continuous sewage treatment process for upgrading the quality of sewage plant effluent by converting sewage sludges to active substances and returning these active substances to the sewage system whereby removal of dissolved contaminants occurs by the addition of the active substances.
Inventors
- 👤 Frank N Kemmer
- 👤 Reid S Robertson
- 👤 Rodney D Mattix
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:47
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1205; C02F3/1226; B; B01; B01D; B01D21/00; B01D21/0012; B01D21/02; B01D21/24; B01D21/2488; C02F1/00; C02F1/28; C02F1/283; C02F1/52; C02F11/00; C02F11/10; C02F9/00; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y02W10/40
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
73 words
The continuous sewage treatment process of claim 1, which includes the additional step of: washing said active substance with a liquid selected from group consisting of water and dilute acid to remove the soluble components before returning said active substance to the sewage system, so as to achieve a concentration level greater than 100 p.p.m. in the system whereby removal of the dissolved organic contaminants occurs by the addition of said active substances.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |