US4347144A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the purification of effluent
Assignee: Hoechst AG
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Filing: 1981-11-06
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Granted: 1982-08-31
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Expires: 2001-11-06
Abstract
Abstract Effluent containing organic impurities which are difficult to degrade is purified by oxidation in the aqueous phase at temperatures of 100° to 310° C. and under elevated pressure. This is effected by initially treating the effluent in a first stage with gases containing oxygen, but without the addition of catalysts, until the C.O.D. value has been reduced by 50 to 98%. The effluent which has received preliminary treatment in this way is subsequently treated, in a second stage, with an oxidizing agent stronger than oxygen, in the liquid phase and at the same, or at a higher, temperature, until the C.O.D. value has fallen to approximately 0 g/l.
Inventors
- 👤 Kurt Bodenbenner
- 👤 Helmut Perkow
- 👤 Helmut Vollmuller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 06:24
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/72; C02F11/00; C02F11/06; C02F11/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
111 words
A process for the purification of effluent containing organic impurities which are difficult to degrade, by oxidation in an aqueous phase at temperatures of 100° to 310° C. and under elevated pressure, the effluent being initially treated in a first stage with gases containing oxygen, but without addition of catalysts, until the C.O.D. value has been reduced by 50 to 98%, which comprises subjecting the effluent which has received preliminary treatment in this way, subsequently, in a second stage, to treatment with an oxidizing agent stronger than oxygen, in the liquid phase and at the same, or at a higher, temperature, until the C.O.D. value has fallen to approximately 0 g/l.
Claim 2
Dependent Claim
111 words
A process for the purification of effluent containing organic impurities which are difficult to degrade, by oxidation in an aqueous phase at temperatures of 100° to 310° C. and under elevated pressure, the effluent being initially treated in a first stage with gases containing oxygen, but without addition of catalysts, until the C.O.D. value has been reduced by 50 to 98%, which comprises subjecting the effluent which has received preliminary treatment in this way, subsequently, in a second stage, to treatment with an oxidizing agent stronger than oxygen, in the liquid phase and at the same, or at a higher, temperature, until the C.O.D. value has fallen to approximately 0 g/l.
Claim 3
Dependent Claim
23 words
A process as claimed in claim 1, wherein nitric acid or a nitrate are used as the oxidizing agent in the second stage.
Claim 4
Dependent Claim
36 words
A process as claimed in claim 2, wherein 0.02 to 0.05 mole of nitric acid or nitrates per g of C.O.D. in the effluent leaving the first stage, are employed for oxidation in the second stage.
Claim 5
Dependent Claim
28 words
A process as claimed in claim 1, wherein the effluent containing the organic impurities which are difficult to degrade, originates from the manufacture of secondary products of cellulose.
Claim 6
Dependent Claim
20 words
A process as claimed in claim 1, wherein the effluent employed also contains chlorides in addition to the organic impurities.
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) | 1985-08-30 | 1986-03-01 | 1986-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-08-30 | 1990-03-01 | 1990-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-08-30 | 1994-03-01 | 1994-08-31 | $7700.00 | Window Closed / Lapsed |