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US4098690A Expired / Lapsed US ⏱️ 0.0 years remaining

Water purification process

Assignee: University of Illinois Foundation
•
Filing: 1976-03-29
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Granted: 1978-07-04
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Expires: 1996-03-29
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Abstract

Abstract A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of: A. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger; B. separating said ion exchanger containing sorbed ammonium ions from the wastewater and then regenerating said ion exchanger and converting the ammonium ions thereon to nitrate ions by treating the ion exchanger with a concentrated salt solution and a culture of nitrifying bacteria whereby ions from the salt solution become absorbed onto the ion exchanger while ammonium ions on the ion exchanger are displaced into solution and oxidized by the nitrifying bacteria to nitrate ions; and, C. recycling the regenerated ion exchanger for further contact with wastewater.

Inventors

  • 👤 Michael J. Semmens

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 05:38
CPC Classifications
B; B01; B01J; B01J39/00; B01J39/02; C; C02; C02F; C02F1/00; C02F1/58; C02F1/586; C02F3/00; C02F3/02; C02F3/12; C02F3/34; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 148 words
A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of: a. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger; b. separating said ion exchanger containing sorbed ammonium ions from the wastewater and then regenerating said ion exchanger and converting the ammonium ions thereon to nitrate ions by treating the ion exchanger with a concentrated salt solution and a culture of nitrifying bacteria whereby ions from the salt solution become sorbed onto the ion exchanger while ammonium ions on the ion exchanger are displaced into solution and oxidized by the nitrifying bacteria to nitrate ions; said salt solution comprising a brine having a concentration of 200 to 500 milliequivalents of sodium nitrate per liter; and, c. recycling the regenerated ion exchanger for further contact with wastewater.
Claim 2
Dependent Claim 148 words
A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of: a. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger; b. separating said ion exchanger containing sorbed ammonium ions from the wastewater and then regenerating said ion exchanger and converting the ammonium ions thereon to nitrate ions by treating the ion exchanger with a concentrated salt solution and a culture of nitrifying bacteria whereby ions from the salt solution become sorbed onto the ion exchanger while ammonium ions on the ion exchanger are displaced into solution and oxidized by the nitrifying bacteria to nitrate ions; said salt solution comprising a brine having a concentration of 200 to 500 milliequivalents of sodium nitrate per liter; and, c. recycling the regenerated ion exchanger for further contact with wastewater.
Claim 3
Dependent Claim 11 words
The process of claim 1 wherein the ion exchanger is clinoptilolite.
Claim 4
Dependent Claim 18 words
The process of claim 1 wherein the nitrification reaction is conducted at a pH of 7 to 9.
Claim 5
Dependent Claim 23 words
The process of claim 1 wherein nitrification is conducted in an aqueous medium having at least 3 milligrams per liter of dissolved oxygen.
Claim 6
Dependent Claim 142 words
A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of: a. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger; b. removing said ion exchanger containing sorbed ammonium ions from contact with the wastewater and then simultaneously regenerating said ion exchanger and converting said ammonium ions to nitrate ions by contacting said ion exchanger with a concentrated salt solution containing nitrifying bacteria, said salt solution comprising a brine having a concentration of 200 to 500 milliequivalents of sodium nitrate per liter, whereby the ammonium ions in the ion exchanger are replaced with ions from the salt solution and the displaced ammonium ions are oxidized by said nitrifying bacteria; and c. recycling the regenerated ion exchanger for further contact with wastewater.
Claim 7
Dependent Claim 142 words
A process for treating wastewaters to reduce the ammonia content thereof comprising the steps of: a. contacting wastewater, having a dissolved ammonia content, with an ion exchanger having an affinity for ammonium ions whereby ammonium ions become sorbed onto said ion exchanger; b. removing said ion exchanger containing sorbed ammonium ions from contact with the wastewater and then simultaneously regenerating said ion exchanger and converting said ammonium ions to nitrate ions by contacting said ion exchanger with a concentrated salt solution containing nitrifying bacteria, said salt solution comprising a brine having a concentration of 200 to 500 milliequivalents of sodium nitrate per liter, whereby the ammonium ions in the ion exchanger are replaced with ions from the salt solution and the displaced ammonium ions are oxidized by said nitrifying bacteria; and c. recycling the regenerated ion exchanger for further contact with wastewater.
Claim 8
Dependent Claim 11 words
The process of claim 5 wherein the ion exchanger is clinoptilolite.
Claim 9
Dependent Claim 18 words
The process of claim 5 wherein the nitrification reaction is conducted at a pH of 7 to 9.
Claim 10
Dependent Claim 23 words
The process of claim 5 wherein nitrification is conducted in an aqueous medium having at least 3 milligrams per liter of dissolved oxygen.

References Cited (Backward Citations)

US3723308A Cited
US3846289A Cited
US3929600A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1981-07-03 1982-01-02 1982-07-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1985-07-03 1986-01-02 1986-07-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1989-07-03 1990-01-02 1990-07-04 $7700.00 Window Closed / Lapsed

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