Patent US4226673A successfully refreshed from Google Patents.
US4226673A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Color removal from paper and pulp mill aqueous effluents
Assignee: Champion International Corp
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Filing: 1976-03-15
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Granted: 1980-10-07
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Expires: 1996-03-15
Abstract
Abstract An improved method for removal of color bodies from aqueous effluents from paper and pulp mill manufacturing operations by ultrafiltration wherein the semi-permeable membrane utilized is a polyethyleneimine coated polysulfone film.
Inventors
- 👤 Henry A. Fremont
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:05
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/44; C02F1/441; C02F1/444
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
47 words
The method of removing color bodies present in an aqueous effluent from paper and pulp mill manufacturing operations comprising subjecting said effluent having a pH of about 11.5 and a temperature of 135° F. to ultrafiltration through a semi-permeable membrane consisting of polysulfone film coated with polyethyleneimine.
Claim 2
Independent Claim
47 words
The method of removing color bodies present in an aqueous effluent from paper and pulp mill manufacturing operations comprising subjecting said effluent having a pH of about 11.5 and a temperature of 135° F. to ultrafiltration through a semi-permeable membrane consisting of polysulfone film coated with polyethyleneimine.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the effluent is a decker effluent.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the polyethyleneimine coating has a thickness of from about 0.3 to about 15.0 A.
Claim 5
Dependent Claim
21 words
The method of claim 1 including the step of filtering the effluent to remove any suspended solids therein prior to ultrafiltration.
Claim 6
Dependent Claim
37 words
The method of claim 1 wherein the polyethyleneimine coating has a thickness of from 1.0 to 5.0 A, the effluent is a decker effluent, and the effluent is filtered to remove any suspended solids prior to ultrafiltration.
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) | 1983-10-07 | 1984-04-07 | 1984-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-07 | 1988-04-07 | 1988-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-07 | 1992-04-07 | 1992-10-07 | $7700.00 | Window Closed / Lapsed |