US3962079A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acid treated cationic starch in the flocculation and dewatering of sludge
Assignee: Anheuser Busch Companies LLC
•
Filing: 1975-02-18
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Granted: 1976-06-08
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Expires: 1995-02-18
Abstract
Abstract This disclosure covers the use of an acid treated, high fluidity, high degree of substitution, waxy maize cationic starch in the flocculation and dewatering of municipal raw primary sludge. From 0.007 to 0.200% (based on the dry weight of the sludge) of the treated starch of about 30 to about 50 fluidity is added to raw primary municipal sludge and contacted with the sewage before the mixture is dewatered to a moisture content below about 70% moisture, which is the moisture level at which the solids will adequately sustain combustion. The starch has from about 0.15 to about 0.25 degree of substitution of an amine butene halide, specifically, 4-chloro-2-butenyl-trimethylammonium chloride.
Inventors
- 👤 Walter G. Hunt
- 👤 Ray J. Belz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:19
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5263; C02F1/54; C08; C08B; C08B31/00; C08B31/08; C08B31/12; C08B31/125
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
74 words
A method of treating municipal raw primary sludge including the steps of adding from about 0.007 to about 0.200% (based on the dry weight of sludge) of an acid treated gelatinized cationic starch ether of amine butene halide having about 0.15 to about 0.25 degree of substitution of amine butene halide and a fluidity of about 30 to about 50 ml., to said municipal raw primary sludge, and dewatering to below about 70% moisture.
Claim 2
Independent Claim
74 words
A method of treating municipal raw primary sludge including the steps of adding from about 0.007 to about 0.200% (based on the dry weight of sludge) of an acid treated gelatinized cationic starch ether of amine butene halide having about 0.15 to about 0.25 degree of substitution of amine butene halide and a fluidity of about 30 to about 50 ml., to said municipal raw primary sludge, and dewatering to below about 70% moisture.
Claim 3
Dependent Claim
27 words
The method of claim 1 wherein the acid treated starch used to prepare the cationic starch ether is gelatinized prior to reaction with the amine butene reagent.
Claim 4
Dependent Claim
12 words
The method of claim 1 wherein the starch ether is 4-chloro-2-butenyltrimethylammonium chloride.
Claim 5
Dependent Claim
12 words
The method of claim 1 wherein the starch is waxy maize starch.
Claim 6
Dependent Claim
20 words
The method of claim 1 wherein the starch is waxy maize starch and the amine butene halide is 4-chloro-2-butenyltrimethylammonium chloride.
References Cited (Backward Citations)
US2876217A
Cited
US2975124A
Cited
US2995513A
Cited
US3423312A
Cited
US3624070A
Cited
US3622563A
Cited
US3842005A
Cited
US3875054A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-06-08 | 1979-12-08 | 1980-06-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-06-08 | 1983-12-08 | 1984-06-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-06-08 | 1987-12-08 | 1988-06-08 | $7700.00 | Window Closed / Lapsed |