US4705633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Nitrification with sludge reaeration and ammonia enrichment
Assignee: Individual
•
Filing: 1986-10-02
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Granted: 1987-11-10
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Expires: 2006-10-02
Abstract
Abstract A nitrification process is disclosed wherein the population of the nitrifying bacteria in an activated sludge system may be increased by the addition of ammonium nitrogen to a return sludge reaeration zone. The increased nitrifying population results in increased reliability of nitrification and lower effluent ammonium nitrogen concentrations.
Inventors
- 👤 Eugene D. Bogusch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:29
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1205; C02F3/1221; C02F3/006; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
185 words
In an activated sludge process for the nitrification of wastewater including a nitrification zone through which the wastewater is continuously passed while being aerated in the presence of activated sludge, a clarifier in which the nitrified wastewater from the nitrification zone is clarified, and a reaeration zone in which separated activated sludge from the clarifier is aerated at a pH of about 6 to 9 before being recycled back into the nitrification zone, the improvement for controlled enrichment of the reaeration zone with ammonium nitrogen, comprising: (a) a step of measuring the ammonium nitrogen concentration in the activated sludge at an outlet of the reaeration zone feeding into the nitrification zone, and (b) a step of adding an ammonium nitrogen enriching agent consisting essentially of anhydrous ammonia to an inlet of the reaeration zone at a controlled rate restricted by the ammonium nitrogen measurement whereby the ammonium nitrogen concentration found at an outlet of the reaeration zone feeding into the nitrification zone is maintained below a predetermined level of about 2 mg/l so as not to adversely affect the nitrification efficiency of the nitrification zone.
Claim 2
Dependent Claim
185 words
In an activated sludge process for the nitrification of wastewater including a nitrification zone through which the wastewater is continuously passed while being aerated in the presence of activated sludge, a clarifier in which the nitrified wastewater from the nitrification zone is clarified, and a reaeration zone in which separated activated sludge from the clarifier is aerated at a pH of about 6 to 9 before being recycled back into the nitrification zone, the improvement for controlled enrichment of the reaeration zone with ammonium nitrogen, comprising: (a) a step of measuring the ammonium nitrogen concentration in the activated sludge at an outlet of the reaeration zone feeding into the nitrification zone, and (b) a step of adding an ammonium nitrogen enriching agent consisting essentially of anhydrous ammonia to an inlet of the reaeration zone at a controlled rate restricted by the ammonium nitrogen measurement whereby the ammonium nitrogen concentration found at an outlet of the reaeration zone feeding into the nitrification zone is maintained below a predetermined level of about 2 mg/l so as not to adversely affect the nitrification efficiency of the nitrification zone.
Claim 3
Dependent Claim
30 words
The process of claim 1 wherein on a daily basis, the ammonium nitrogen enrichment is discontinued after a predetermined amount of ammonium nitrogen has been added to the reaeration zone.
Claim 4
Dependent Claim
26 words
The process of claim 1 wherein the ammonium nitrogen enrichment is made into the separated activated sludge from the clarifier before entry into said reaeration zone.
Claim 5
Dependent Claim
39 words
The process of claim 1 wherein the ammonium nitrogen concentration of the activated sludge is measured by the ammonia-selective electrode method, after a physical separation of the suspended solids in a sample of the activated sludge has been made.
Claim 6
Dependent Claim
189 words
In an activated sludge process for the nitrification of wastewater including a nitrification zone through which the wastewater is continuously passed while being aerated in the presence of activated sludge, a clarifier in which the nitrified wastewater from the nitrification zone is clarified, and a reaeration zone in which separated activated sludge from the clarifier is aerated at a pH of about 6 to 9 before being recycled back into the nitrification zone, the improvement for controlled enrichment of the reaeration zone with ammonium nitrogen, comprising: (a) a step of measuring ammonium nitrogen in the activated sludge at an outlet of the reaeration zone feeding into the nitrification zone, and (b) a step of adding an ammonium nitrogen enriching agent consisting essentially of an aqueous ammonium solution derived from anhydrous ammonia to an inlet of the reaeration zone at a controlled rate restricted by the ammonium nitrogen measurement whereby the ammonium nitrogen concentration found at an outlet of the reaeration zone feeding into the nitrification zone is maintained below a predetermined level of about 2 mg/l so as not to adversely affect the nitrification efficiency of the nitrification zone.
Claim 7
Dependent Claim
189 words
In an activated sludge process for the nitrification of wastewater including a nitrification zone through which the wastewater is continuously passed while being aerated in the presence of activated sludge, a clarifier in which the nitrified wastewater from the nitrification zone is clarified, and a reaeration zone in which separated activated sludge from the clarifier is aerated at a pH of about 6 to 9 before being recycled back into the nitrification zone, the improvement for controlled enrichment of the reaeration zone with ammonium nitrogen, comprising: (a) a step of measuring ammonium nitrogen in the activated sludge at an outlet of the reaeration zone feeding into the nitrification zone, and (b) a step of adding an ammonium nitrogen enriching agent consisting essentially of an aqueous ammonium solution derived from anhydrous ammonia to an inlet of the reaeration zone at a controlled rate restricted by the ammonium nitrogen measurement whereby the ammonium nitrogen concentration found at an outlet of the reaeration zone feeding into the nitrification zone is maintained below a predetermined level of about 2 mg/l so as not to adversely affect the nitrification efficiency of the nitrification zone.
Claim 8
Dependent Claim
30 words
The process of claim 5 wherein on a daily basis, the ammonium nitrogen enrichment is discontinued after a predetermined amount of ammonium nitrogen has been added to the reaeration zone.
Claim 9
Dependent Claim
26 words
The process of claim 5 wherein the ammonium nitrogen enrichment is made into the separated activated sludge from the clarifier before entry into said reaeration zone.
Claim 10
Dependent Claim
39 words
The process of claim 5 wherein the ammonium nitrogen concentration of the activated sludge is measured by the ammonia-selective electrode method, after a physical separation of the suspended solids in a sample of the activated sludge has been made.
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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) | 1990-11-09 | 1991-05-11 | 1991-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-11-09 | 1995-05-11 | 1995-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-11-09 | 1999-05-11 | 1999-11-10 | $7700.00 | Window Closed / Lapsed |