US3684702A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for determining the biochemical decomposability of sewage
Assignee: Siemens Water Technologies Holding Corp
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Filing: 1971-01-29
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Granted: 1972-08-15
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Expires: 1991-01-29
Abstract
Abstract TEST SAMPLES OF INCOMING SEWAGE ARE MIXED WITH RELATIVELY LARGE SAMPLES OF ACTIVATED SLUDGE FROM PREVIOUSLY TREATED SEWAGE AND UNDER CONTROLLED CONDITIONS THE BIOLOGICAL OXYGEN DEMAND IS MEASURED IN A SHORT PERIOD OF TIME. ON THE BASIS OF THIS MEASUREMENT THE RECYCLING OF ACTIVATED SLUDGE TO THE MAIN SEWAGE AERATING TANKS CAN BE ACCURATELY CALCULATED AND CONTROLLED TO PROVIDE FOR THE OPTIMUM BIOLOGICAL DECOMPOSITION OF THE SEWAGE. THE TESTING CAN BE FREQUENTLY REPEATED TO CONSTANTLY MONITOR THE QUALITY OF THE INCOMING SEWAGE TO PROVIDE UPDATED INFORMATION TO EFFECTIVELY CONTROL THE DECOMPOSITION OF THE SEWAGE UNDER OPTIMUM CONDITIONS.
Inventors
- 👤 Ludwig Hartmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:41
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/006
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |