US3975266A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dewatering process
Assignee: Individual
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Filing: 1974-11-06
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Granted: 1976-08-17
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Expires: 1994-11-06
Abstract
Abstract A dewatering process for the separation and recovery of sludge from water reservoirs, such as, lakes, ponds, lagoons, rivers and the like is provided. The process includes the steps of dredging the reservoir, thickening the suspended matter in the water, dewatering the thickened matter and, then, recovering the sludge therefrom. The process further contemplates the addition of a flocculant to the dredged material between the dredging and thickening steps and/or between the thickening and dewatering steps.
Inventors
- 👤 Sylvia S. Baize
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:19
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; B; B01; B01D; B01D21/00; B01D21/01; C02F1/54; C02F11/00; C02F11/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
33 words
In a dredging process for the recovery of activated sludge from water, the improvement comprising: a. dredging a mass of water having solids suspended therein, b. admixing a flocculant with the dredge by:
Claim 2
Dependent Claim
33 words
In a dredging process for the recovery of activated sludge from water, the improvement comprising: a. dredging a mass of water having solids suspended therein, b. admixing a flocculant with the dredge by:
Claim 3
Dependent Claim
112 words
dissolving the flocculant in water to form a solution thereof, 2. transferring the solution to a holding tank, and 3. metering the solution to the dredge from the holding tank, c. thickening the suspended matter in the water, d. dewatering the thickened matter, e. adding chlorine to the dewatered thickened matter, f. recovering the thickened matter from the dewatering step, and wherein the flocculant is selected from the group consisting of ferric sulfate, ferrous sulfate, calcium hydroxide, diatomaceous earth, bentonite, alum, anionic polymers, cationic polymers and mixtures thereof, the flocculant being employed in an amount ranging from about 0.5 to 200 ppm, by weight, per million parts by weight of dredged water.
Claim 4
Dependent Claim
112 words
dissolving the flocculant in water to form a solution thereof, 2. transferring the solution to a holding tank, and 3. metering the solution to the dredge from the holding tank, c. thickening the suspended matter in the water, d. dewatering the thickened matter, e. adding chlorine to the dewatered thickened matter, f. recovering the thickened matter from the dewatering step, and wherein the flocculant is selected from the group consisting of ferric sulfate, ferrous sulfate, calcium hydroxide, diatomaceous earth, bentonite, alum, anionic polymers, cationic polymers and mixtures thereof, the flocculant being employed in an amount ranging from about 0.5 to 200 ppm, by weight, per million parts by weight of dredged water.
Claim 5
Dependent Claim
24 words
The process of claim 1 which further includes the step of: admixing a flocculant with the thickened matter intermediate the thickening and dewatering steps.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the flocculant is an anionic or cationic polymer.
Claim 7
Dependent Claim
24 words
The process of claim 3 wherein the flocculant is admixed with the dredge as a 0.25 to 1 percent, by weight, aqueous solution thereof.
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) | 1979-08-17 | 1980-02-16 | 1980-08-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-17 | 1984-02-16 | 1984-08-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-17 | 1988-02-16 | 1988-08-17 | $7700.00 | Window Closed / Lapsed |