US4104162A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for detoxification of formaldehyde containing waste waters
Assignee: Evonik Operations GmbH
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Filing: 1975-08-04
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Granted: 1978-08-01
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Expires: 1995-08-04
Abstract
Abstract Formaldehyde containing waste water is detoxified by treating the waste water with hydrogen peroxide in the presence of alkali at an initial temperature of 10°-35° C. In an alternative and preferred form of the invention the waste water is heated to a temperature of at least 50° C and then 10-35% of the hydrogen peroxide equivalent to the formaldehyde is added.
Inventors
- 👤 Helmut Junkermann
- 👤 Heinrich Schwab
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:13
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/72; C02F1/722
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
43 words
A process for detoxifying formaldehyde containing waste water comprising treating the waste water with an alkaline material at a temperature of at least 50° C. and then adding hydrogen peroxide in an amount equivalent to 10-35% of the formaldehyde in the waste water.
Claim 2
Dependent Claim
43 words
A process for detoxifying formaldehyde containing waste water comprising treating the waste water with an alkaline material at a temperature of at least 50° C. and then adding hydrogen peroxide in an amount equivalent to 10-35% of the formaldehyde in the waste water.
Claim 3
Dependent Claim
17 words
The process of claim 1 wherein the temperature of the alkaline treatment is 50° to 100° C.
Claim 4
Dependent Claim
15 words
The process of claim 2 wherein the temperature of the alkaline treatment is 60°-85° C.
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the waste water contains 0.01 to 10% formaldehyde.
Claim 6
Dependent Claim
14 words
The process of claim 4 wherein the waste water contains 0.02 to 7% formaldehyde.
Claim 7
Dependent Claim
17 words
The process of claim 5 wherein the waste water is from a plant making formaldehyde containing resins.
Claim 8
Dependent Claim
20 words
The process of claim 5 wherein the alkaline material is an alkali metal hydroxide or an alkaline earth metal hydroxide.
Claim 9
Dependent Claim
12 words
The process of claim 7 wherein the alkaline material is sodium hydroxide.
Claim 10
Dependent Claim
12 words
The process of claim 7 wherein the alkaline material is calcium hydroxide.
Claim 11
Dependent Claim
23 words
The process of claim 7 wherein the alkaline material is sodium hydroxide or calcium hydroxide and the temperature is 50° to 100° C.
References Cited (Backward Citations)
US3829379A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-31 | 1982-01-30 | 1982-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-31 | 1986-01-30 | 1986-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-31 | 1990-01-30 | 1990-08-01 | $7700.00 | Window Closed / Lapsed |