Patent US4228003A successfully refreshed from Google Patents.
US4228003A
Expired / Lapsed
US
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Method of removing phosphates from waste water
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1979-04-17
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Granted: 1980-10-14
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Expires: 1999-04-17
Abstract
Abstract Removal of phosphates from waste water can be attained with improved efficiency and at low cost by admixing the waste water with seawater and adjusting the mixture to pH 9-11 to separate the sedimental phosphates. The sediment can be utilized as phosphatic fertilizer.
Inventors
- 👤 Yutaka Makino
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:29
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/906; Y10S210/907
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
44 words
A method of removing phosphates from waste water which comprises admixing the waste water with seawater in a volume ratio of 95:5 to 50:50 and adjusting the mixture to pH 9-11 with an alkaline agent to separate the sedimental phosphates by way of coagulation.
Claim 2
Independent Claim
44 words
A method of removing phosphates from waste water which comprises admixing the waste water with seawater in a volume ratio of 95:5 to 50:50 and adjusting the mixture to pH 9-11 with an alkaline agent to separate the sedimental phosphates by way of coagulation.
Claim 3
Dependent Claim
22 words
A method according to claim 1, wherein the waste water and seawater are admixed in a volume ratio of 90:10 to 70:30.
Claim 4
Dependent Claim
18 words
A method according to claim 1, wherein the mixture is adjusted to a pH of 9.3 to 10.5.
Claim 5
Dependent Claim
33 words
A method according to claim 1, wherein the waste water and seawater are admixed in a volume of 90:10 to 70:30 and the mixture is adjusted to a pH of 9.3 to 10.5.
Claim 6
Dependent Claim
16 words
A method according to claim 1, wherein a polymeric organic coagulant is added to the mixture.
Claim 7
Dependent Claim
18 words
A method according to claim 1, wherein the alkaline agent is a spent alkaline liquor containing sodium hydroxide.
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) | 1983-10-14 | 1984-04-14 | 1984-10-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-10-14 | 1988-04-14 | 1988-10-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-10-14 | 1992-04-14 | 1992-10-14 | $7700.00 | Window Closed / Lapsed |