US4200526A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for treating waste water
Assignee: Gerber Products Co
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Filing: 1978-03-06
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Granted: 1980-04-29
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Expires: 1998-03-06
Abstract
Abstract A purification process for waste water from a textile plant and other manufacturing processes. After preliminary filtering to remove foreign particles, the waste water is treated with a reducing agent, if needed, and the pH adjusted to 8.0-9.5. The waste water is then treated with a flocculating agent. After further treatment in a clarifier, the waste water is passed through a sand filter to remove any residual suspended solids. The pH is adjusted to below about 6.0 and the waste water is then subjected to reverse osmosis.
Inventors
- 👤 Earl W. Johnson
- 👤 Malcolm J. Reider
- 👤 Robert Anewalt
- 👤 Harry J. Kring
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:30
CPC Classifications
C; C02; C02F; C02F9/00; B; B01; B01D; B01D61/00; B01D61/02; B01D61/025; C02F1/00; C02F1/66; B01D2311/00; B01D2311/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
115 words
A process for treating textile plant waste water containing at least 50 ppm surface active agent consisting essentially of: adding iron salt as the sole chemical reagent in an amount sufficient to enable the turbidity to be subsequently adjusted to less than 10 JTU; PG,13 adding lime slurry in an amount sufficient to adjust the pH of the waste water to about 8.0-9.5; allowing sufficient solids to precipitate from the pH adjusted waste water to achieve said turbidity; separating effluent from said precipitated solids; passing said separated effluent through at least one sand filter; adjusting the pH of the filtered effluent to below about 6.0; and subjecting said pH adjusted filtered effluent to reverse osmosis.
Claim 2
Dependent Claim
115 words
A process for treating textile plant waste water containing at least 50 ppm surface active agent consisting essentially of: adding iron salt as the sole chemical reagent in an amount sufficient to enable the turbidity to be subsequently adjusted to less than 10 JTU; PG,13 adding lime slurry in an amount sufficient to adjust the pH of the waste water to about 8.0-9.5; allowing sufficient solids to precipitate from the pH adjusted waste water to achieve said turbidity; separating effluent from said precipitated solids; passing said separated effluent through at least one sand filter; adjusting the pH of the filtered effluent to below about 6.0; and subjecting said pH adjusted filtered effluent to reverse osmosis.
Claim 3
Dependent Claim
30 words
A process in accordance with claim 1 and further characterized by subjecting said waste water to preliminary treatment with an alkali metal sulfite to remove any residual hydrogen peroxide present.
Claim 4
Dependent Claim
18 words
The process of claim 2 wherein the alkali metal sulfite for removing excess hydrogen peroxide is sodium bisulfite.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein the iron salt is ferrous sulfate.
Claim 6
Dependent Claim
12 words
The process of claim 1 wherein the iron salt is ferric chloride.
Claim 7
Dependent Claim
28 words
The process of claim 1 wherein the pH of the sand filtered effluent is adjusted to a value between 5.0 and 6.0 by the addition of sulphuric acid.
Claim 8
Dependent Claim
21 words
The process of claim 1 and further characterized by adding sodium hexametaphosphate to the pH adjusted effluent prior to reverse osmosis.
References Cited (Backward Citations)
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-04-29 | 1983-10-29 | 1984-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-04-29 | 1987-10-29 | 1988-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-04-29 | 1991-10-29 | 1992-04-29 | $7700.00 | Window Closed / Lapsed |