US4118319A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treatment of sludge
Assignee: Tosoh Corp
•
Filing: 1977-03-03
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Granted: 1978-10-03
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Expires: 1997-03-03
Abstract
Abstract Light burned magnesia is added to sludge which comprises biological aggregate or polyvalent metal hydroxide aggregate to improve filtering characteristics.
Inventors
- 👤 Isao Miyanohara
- 👤 Hiroshi Miyazaki
- 👤 Hideo Kawamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 02:20
CPC Classifications
B; B01; B01D; B01D37/00; B01D37/03; C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
41 words
A treatment of a sludge containing biological aggregate or polyvalent metal hydroxide aggregate, which consists of adding light burned magnesia to said sludge, adjusting the pH of said sludge to the range of from 9 to 12 and filtering said sludge.
Claim 2
Dependent Claim
41 words
A treatment of a sludge containing biological aggregate or polyvalent metal hydroxide aggregate, which consists of adding light burned magnesia to said sludge, adjusting the pH of said sludge to the range of from 9 to 12 and filtering said sludge.
Claim 3
Dependent Claim
21 words
A treatment of a sludge according to claim 1, wherein said light burned magnesia is added together with an iron salt.
Claim 4
Dependent Claim
31 words
A treatment of a sludge according to claim 1, wherein said light burned magnesia is added at a ratio of 1 to 1,000 wt. % to solid components in the sludge.
Claim 5
Dependent Claim
28 words
A treatment of a sludge according to claim 1, wherein said light burned magnesia is added to a sludge containing biological aggregate which is formed by microorganism treatment.
Claim 6
Dependent Claim
34 words
A treatment of a sludge according to claim 1, wherein said light burned magnesia is added to a sludge resulted by adding an aluminum type coagulant or an iron type coagulant to a drainage.
Claim 7
Dependent Claim
22 words
A treatment of a sludge according to claim 1, wherein a base is added to give the pH of 9 to 12.
Claim 8
Dependent Claim
33 words
A treatment of a sludge according to claim 1, wherein light burned magnesia is added with another magnesium compound with or without a base so as to be pH of 9 to 12.
Claim 9
Dependent Claim
32 words
A treatment of a sludge according to claim 7, wherein said magnesium compound is selected from the group consisting of magnesium hydroxide, magnesium chloride, magnesium sulfate, magnesium carbonate and basic magnesium carbonate.
Claim 10
Dependent Claim
33 words
A treatment of a sludge according to claim 1, wherein an iron salt is added with light burned magnesia with or without a base so as to be pH of 9 to 12.
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) | 1981-10-02 | 1982-04-03 | 1982-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-10-02 | 1986-04-03 | 1986-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-10-02 | 1990-04-03 | 1990-10-03 | $7700.00 | Window Closed / Lapsed |