US4663043A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of treating peroxide-containing wastewater
Assignee: Purac AB
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Filing: 1984-08-06
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Granted: 1987-05-05
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Expires: 2004-08-06
Abstract
Abstract It was found difficult to carry out anaerobic treatment of peroxide-containing wastewater. According to the invention, the problem is solved in that the peroxide content of the water is reduced in a catalytic pretreatment step (1), preferably an enzymatic pretreatment step.
Inventors
- 👤 Nils L. Molin
- 👤 Thomas G. Welander
- 👤 Bengt G. Hansson
- 👤 Per-Erik Andersson
- 👤 Bengt A. G. Olsson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:05
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/28; C02F3/286; C02F3/30; C02F3/34; C02F3/342; Y; Y02; Y02E; Y02E50/00; Y02E50/30; Y10; Y10S; Y10S210/00; Y10S210/928
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
89 words
A method for an anaerobic treatment of a peroxide-containing wastewater from the production of mechanical or chemi-mechanical cellulose pulp comprising: (i) subjecting the wastewater to an enzymatic pre-treatment step wherein the peroxide in said wastewater is substantially destroyed; (ii) subjecting the wastewater of step (i) to a hydrolysis and acid fermentation step; (iii) subjecting the wastewater of step (ii) to a methane fermentation step; and (iv) subjecting the wastewater of step (iii) to an aerobic step, the enzymes for said pre-treatment step (i) being generated in the aerobic step.
Claim 2
Independent Claim
89 words
A method for an anaerobic treatment of a peroxide-containing wastewater from the production of mechanical or chemi-mechanical cellulose pulp comprising: (i) subjecting the wastewater to an enzymatic pre-treatment step wherein the peroxide in said wastewater is substantially destroyed; (ii) subjecting the wastewater of step (i) to a hydrolysis and acid fermentation step; (iii) subjecting the wastewater of step (ii) to a methane fermentation step; and (iv) subjecting the wastewater of step (iii) to an aerobic step, the enzymes for said pre-treatment step (i) being generated in the aerobic step.
Claim 3
Dependent Claim
17 words
The method according to claim 1, wherein enzymes for said enzymatic pre-treatment step are comprised of catalase.
Claim 4
Dependent Claim
40 words
The method according to claim 1 further comprising the steps of: continuously measuring the redox potential value of the wastewater during said hydrolysis and acid fermentation step; using said value for regulating transfer of sludge to said enzymatic pre-treatment step.
Claim 5
Dependent Claim
46 words
The method according to claim 1 further comprising: carrying out a sedimentation step after at least one of said hydrolysis and acid fermentation step and said aerobic step whereby a bacteria sludge is separated from said wastewater; transferring said bacteria sludge to said enzymatic pre-treatment step.
Claim 6
Dependent Claim
23 words
The method according to claim 1 wherein at least one of heavy metal and heavy metal compounds are used in said pre-treatment step.
Claim 7
Dependent Claim
14 words
The method according to claim 5 wherein said heavy metal is iron or manganese.
Claim 8
Independent Claim
91 words
A method for anaerobic treatment of a peroxide-containing wastewater from the production of mechanical or chemi-mechanical cellulose pulp comprising: (i) subjecting the wastewater to an enzymatic pre-treatment step wherein the peroxide in said wastewater is substantially destroyed; (ii) subjecting the wastewater of step (i) to a hydrolysis and acid fermentation step, the enzymes for said pre-treatment step (i) being generated in said hydrolysis and acid fermentation step; (iii) subjecting the wastewater of step (ii) to a methane fermentation step; and (iv) subjecting the watewater of step (iii) to an aerobic step.
Claim 9
Independent Claim
91 words
A method for anaerobic treatment of a peroxide-containing wastewater from the production of mechanical or chemi-mechanical cellulose pulp comprising: (i) subjecting the wastewater to an enzymatic pre-treatment step wherein the peroxide in said wastewater is substantially destroyed; (ii) subjecting the wastewater of step (i) to a hydrolysis and acid fermentation step, the enzymes for said pre-treatment step (i) being generated in said hydrolysis and acid fermentation step; (iii) subjecting the wastewater of step (ii) to a methane fermentation step; and (iv) subjecting the watewater of step (iii) to an aerobic step.
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) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |