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US4247645A
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Process for removing melamine from melamine-containing liquids
Assignee: Stamicarbon BV
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Filing: 1979-03-19
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Granted: 1981-01-27
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Expires: 1999-03-19
Abstract
Abstract A process for removing melamine from liquids containing melamine by biological means. The aqueous solution or suspension of melamine is brought into contact with microorganisms or enzyme preparations having melaminase activity, and the resulting mixture is maintained under anaerobic conditions whereby at least a portion of the melamine is biodegraded.
Inventors
- 👤 Lucia R. M. Meijer-Hoffman
- 👤 Pieter H. de Jonge
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 01:21
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/34; C02F3/28; C02F3/342; Y; Y10; Y10S; Y10S435/00; Y10S435/8215; Y10S435/822; Y10S435/824; Y10S435/828; Y10S435/829; Y10S435/832; Y10S435/839; Y10S435/84; Y10S435/859; Y10S435/874; Y10S435/875; Y10S435/882; Y10S435/883
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
87 words
A process for removing melamine from melamine-containing liquids essentially comprising bringing an aqueous solution or suspension of melamine into contact with a medium having melaminase activity, selected from the group consisting of microorganisms and enzyme preparations having melaminase activity, or a combination thereof, and maintaining the resulting mixture under anaerobic conditions, with a molecular oxygen concentration of less than about 0.1 ppm, and maintaining the nitrate ion concentration of said mixture at less than about 10 ppm, whereby at least a portion of said melamine is biodegraded.
Claim 2
Dependent Claim
87 words
A process for removing melamine from melamine-containing liquids essentially comprising bringing an aqueous solution or suspension of melamine into contact with a medium having melaminase activity, selected from the group consisting of microorganisms and enzyme preparations having melaminase activity, or a combination thereof, and maintaining the resulting mixture under anaerobic conditions, with a molecular oxygen concentration of less than about 0.1 ppm, and maintaining the nitrate ion concentration of said mixture at less than about 10 ppm, whereby at least a portion of said melamine is biodegraded.
Claim 3
Dependent Claim
22 words
The process of claim 1 wherein the total concentration of nitrite and nitrate ions in said mixture is less than 10 ppm.
Claim 4
Dependent Claim
20 words
The process of claims 1 or 2 wherein said medium is present in the form of microorganism containing activated sludge.
Claim 5
Dependent Claim
28 words
The process of claim 3 wherein said aqueous solution or suspension of melamine is brought into contact with said microorganism containing activated sludge in an upward flow reactor.
Claim 6
Dependent Claim
35 words
The process of claims 1 or 2 wherein said medium having melaminase activity contains at least one strain of microorganisms selected from the genera consisting of Achromobacter, Aerobacter, Pseudomonas, Micrococcus, Staphylococcus, Bacillus, Brevibacterium and Alcaligenes.
Claim 7
Dependent Claim
40 words
The process of claim 5 wherein said medium contains at least one strain of microorganisms selected from the species consisting of Achromobacter lacticum, Aerobacter aerogenes, Pseudomonas aeruginosa, Micrococcus albus, Staphylococcus aureus, Bacillus pasteurii, Bacillus subtillis, Brevibacterium roseum and Alcaligenes faecalis.
Claim 8
Dependent Claim
63 words
The process of claim 6 wherein said medium contains at least one strain of microorganisms selected from the group consisting of Achromobacter lacticum NCIB 8208, Aerobacter aerogenes NCIB 11402, Pseudomonas aeruginosa NCIB 11403, Micrococcus albus NCIB 11404, Staphylococcus aureus ATCC 8532, Bacillus pasteurii NCIB 11360, ATCC 11859 and NCIB 11395, Bacillus subtilis ATCC 15841, Brevibacterium roseum ATCC 13825 and Alcaligenes faecalis NCIB 11396.
Claim 9
Dependent Claim
29 words
The process of claims 1 or 2 wherein the pH of said mixture is maintained at a value of between 8 and 11 during the biodegradation of said melamine.
Claim 10
Dependent Claim
17 words
The process of claims 1 or 2 wherein an assimilable carbon source is added to said mixture.
Claim 11
Dependent Claim
27 words
The process of claims 1 or 2 wherein the temperature of said mixture is maintained at between 15° and 60° C. during the biodegradation of said melamine.
Claim 12
Dependent Claim
15 words
The process of claim 10 wherein said temperature is maintained between 30° and 45° C.
Claim 13
Dependent Claim
30 words
The process of claims 1 or 2 wherein the average time of contact between said aqueous solution or suspension of melamine and said medium is between 3 and 24 hours.
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) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |