US4066542A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of purification of waste water by treatment with zirconium salt
Assignee: Shikoku Paper Manufacturing Co
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Filing: 1976-08-09
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Granted: 1978-01-03
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Expires: 1996-08-09
Abstract
Abstract The present invention refers to a method of purification of waste water from chemical pulping and paper mills comprising coagulate and precipitate suspended substances and colloidal dispersed particles, and precipitation of non-colloidal dissolved, low molecular weight substances in the waste water and form water insoluble precipitates or chelates thereof, and further to a method of purification of waste water of any source by the use of zirconium salt.
Inventors
- 👤 Buichiro Ayukawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 04:58
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/72; Y; Y02; Y02W; Y02W10/00; Y02W10/30; Y02W10/37
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
64 words
A process for the purification of surface water which comprises adding an aqueous solution of ZrOCl 2 .8H 2 O to said surface water and adjusting the pH to 4.5-6.8 to coagulate and precipitate suspended substances and colloidal dispersed particles and precipitate non-colloidal dissolved, low molecular weight organic substances therein in the form of insoluble precipitates and chelates, and removing said precipitates and chelates.
Claim 2
Dependent Claim
64 words
A process for the purification of surface water which comprises adding an aqueous solution of ZrOCl 2 .8H 2 O to said surface water and adjusting the pH to 4.5-6.8 to coagulate and precipitate suspended substances and colloidal dispersed particles and precipitate non-colloidal dissolved, low molecular weight organic substances therein in the form of insoluble precipitates and chelates, and removing said precipitates and chelates.
Claim 3
Dependent Claim
13 words
The process according to claim 1 wherein the surface water is river water.
References Cited (Backward Citations)
US1173698A
Cited
US2204812A
Cited
US2903335A
Cited
US2917359A
Cited
US3730886A
Cited
US3997439A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |