US4029574A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for the purification of organically contaminated sewage
Assignee: Linde GmbH
•
Filing: 1972-09-18
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Granted: 1977-06-14
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Expires: 1992-09-18
Abstract
Abstract An activated sludge process for the purification of sewage by aerating a sewage-activated sludge mixture with oxygen or oxygen-enriched air is described wherein at least a portion of the gaseous mixture exiting from the aeration tank is collected, at least a portion of gaseous metabolic product separated therefrom, and the purified gas recycled to the aeration tank. Concentration gradients of O 2 and gaseous metabolic products are thereby reduced, improving the efficiency of the sewage treatment processing, and pure CO 2 can be recovered as an end product.
Inventors
- 👤 Hans Reimann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 21:05
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/26; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
148 words
In an activated sludge process wherein sewage is oxygenated with oxygen or oxygen-enriched air containing at least 40% oxygen in an aeration tank containing a sewage-activated sludge mixture, the improvement which comprises: a. collecting at least a portion of a gaseous mixture exiting from the aeration tank said gaseous mixture containing unconsumed oxygen and gaseous metabolic products, primarily CO 2 ; b. separating at least a major portion of said CO 2 present in said gaseous metabolic products from said gaseous mixture by condensation, adsorption or scrubbing to form a purified gaseous mixture containing oxygen; and c. recycling the purified gaseous mixture containing oxygen to an inlet of the aeration tank to further oxygenate the sewage-activated sludge mixture therein, and adding makeup oxygen in an amount corresponding to the oxygen consumption of the sewage-activated sludge mixture to maintain the at least 40% oxygen concentration in the aeration tank.
Claim 2
Dependent Claim
148 words
In an activated sludge process wherein sewage is oxygenated with oxygen or oxygen-enriched air containing at least 40% oxygen in an aeration tank containing a sewage-activated sludge mixture, the improvement which comprises: a. collecting at least a portion of a gaseous mixture exiting from the aeration tank said gaseous mixture containing unconsumed oxygen and gaseous metabolic products, primarily CO 2 ; b. separating at least a major portion of said CO 2 present in said gaseous metabolic products from said gaseous mixture by condensation, adsorption or scrubbing to form a purified gaseous mixture containing oxygen; and c. recycling the purified gaseous mixture containing oxygen to an inlet of the aeration tank to further oxygenate the sewage-activated sludge mixture therein, and adding makeup oxygen in an amount corresponding to the oxygen consumption of the sewage-activated sludge mixture to maintain the at least 40% oxygen concentration in the aeration tank.
Claim 3
Dependent Claim
31 words
A process according to claim 1 further comprising venting a portion of said purified gaseous mixture from the sewage treatment system to prevent a build-up of nitrogen in said gaseous mixture.
Claim 4
Dependent Claim
42 words
A process according to claim 1 further comprising feeding at least a portion of the purified gaseous mixture to an air separation plant, separating oxygen therefrom, and using said oxygen as a source of gaseous oxygen fed to said oxygen aerator tank.
Claim 5
Dependent Claim
12 words
A process according to claim 3 wherein said separation is effected cryogenically.
Claim 6
Dependent Claim
15 words
A process according to claim 3 wherein said separation is effected by pressure change adsorption.
Claim 7
Dependent Claim
19 words
A process according to claim 3 wherein the oxygen-rich gaseous product is fed directly to said oxygen aeration tank.
Claim 8
Dependent Claim
16 words
A process according to claim 1 further comprising recovering said CO 2 in the pure form.
Claim 9
Dependent Claim
50 words
A process according to claim 7 further comprising separating said collected gaseous mixture into two portions, conducting the separation of said CO 2 in the gaseous metabolic products from one portion prior to recycling, and recycling the other portion to said oxygen aeration tank without separating gaseous metabolic products therefrom.
Claim 10
Dependent Claim
41 words
A processs according to claim 8 further comprising adding gaseous oxygen in an amount corresponding to the oxygen consumption of the sewage-activated sludge mixture to at least one of said two portions before recycling that portion to the oxygen aeration tank.
Claim 11
Dependent Claim
19 words
A process according to claim 9 wherein gaseous oxygen is added to said other portion of said gaseous mixture.
Claim 12
Dependent Claim
26 words
A process according to claim 10 wherein gaseous oxygen is added in the form of a gas composition consisting of at least 50 vol % oxygen.
Claim 13
Dependent Claim
26 words
A process according to claim 1 further comprising treating at least a portion of said collected gaseous mixture to remove volatile, odiferous or poisonous components therefrom.
Claim 14
Dependent Claim
90 words
Apparatus suitable for conducting a process according to claim 1 comprising at least one activated sludge tank, a blower, CO 2 separation means, said means comprising condensation means, adsorption means or stripping means, and means for the production of oxygen or oxygen-enriched air, wherein the activated sludge tank, the blower and the CO 2 separation means are connected in series, and the means for the production of oxygen is in communication with an inlet to the activated sludge tank and with a conduit leading from the CO 2 separation means.
Claim 15
Dependent Claim
22 words
Apparatus according to claim 13, wherein said means for the production of oxygen or oxygen-enriched air is a cryogenic air separation plant.
Claim 16
Dependent Claim
39 words
A process according to claim 1, further comprising adding gaseous oxygen to the purified gaseous mixture in an amount corresponding to the oxygen consumption of the sewage-activated sludge mixture before recycling the purified gaseous mixture to the aeration tank.
References Cited (Backward Citations)
US2097454A
Cited
US3547812A
Cited
US3577678A
Cited
US3670887A
Cited
US3660277A
Cited
US3748262A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-06-13 | 1980-12-13 | 1981-06-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-06-13 | 1984-12-13 | 1985-06-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-06-13 | 1988-12-13 | 1989-06-14 | $7700.00 | Window Closed / Lapsed |