Patent JPS5895231A successfully refreshed from Google Patents.
US4132636A
Expired / Lapsed
US
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Method for treating gas liquor
Assignee: Niigata Engineering Co Ltd
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Filing: 1977-11-28
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Granted: 1979-01-02
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Expires: 1997-11-28
Abstract
Abstract A method for treating a gas liquor to remove polluting substances with a stable treating efficiency and at a high rate which comprises the steps of (A) pre-treating a gas liquor discharged from a quenching of coke oven gas, the gas liquor containing ammonia, phenols, thiocyanate compounds, cyanide compounds, suspended solids and oils, to reduce the ammonia content of the gas liquor to about 1,000 ppm or less; (B) subjecting the gas liquor from step (A) to a first biological treatment comprising treating the gas liquor treated in step (A) with microorganisms, (C) subjecting the gas liquor from step (B) to a second biological treatment comprising treating the gas liquor treated in step (B) in an aerating tank including a mixture of suspended solids comprising powdered activated carbon and activated sludge mixed with the gas liquor, and (D) adding an iron salt to the gas liquor from step (C) to cause coagulation and sedimentation.
Inventors
- 👤 Toshio Iwase
- 👤 Teruo Hashimoto
- 👤 Youko Iguchi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 06:28
CPC Classifications
C; C02; C02F; C02F1/00; C02F1/52; C02F1/5236; C02F1/5245; C01; C01C; C01C3/00; C01C3/08; C01C3/12; C02F2101/00; C02F2101/10; C02F2101/16; C02F2101/18; C02F2103/00; C02F2103/18; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903; Y10S210/904; Y10S210/908; Y10S210/909
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
139 words
A method for treating a gas liquor discharged from the quenching of a coke oven gas, the gas liquor containing ammonia, phenols, thiocyanate compounds, cyanide compounds, suspended solids and oils, which comprises the steps of (A) reducing the ammonia content of the gas liquor to about 1,000 ppm or less; (B) subjecting the gas liquor from step (A) to a first biological treatment comprising treating the gas liquor treated in step (A) with microorganisms; (C) subjecting the gas liquor treated in step (B) to a second biological treatment comprising treating the gas liquor treated in step (B) in an aeration tank including a mixture of suspended solids comprising powdered activated carbon and activated sludge mixed with the gas liquor; and (D) adding an iron salt to the gas liquor from step (C) to cause a coagulation and a sedimentation.
Claim 2
Independent Claim
139 words
A method for treating a gas liquor discharged from the quenching of a coke oven gas, the gas liquor containing ammonia, phenols, thiocyanate compounds, cyanide compounds, suspended solids and oils, which comprises the steps of (A) reducing the ammonia content of the gas liquor to about 1,000 ppm or less; (B) subjecting the gas liquor from step (A) to a first biological treatment comprising treating the gas liquor treated in step (A) with microorganisms; (C) subjecting the gas liquor treated in step (B) to a second biological treatment comprising treating the gas liquor treated in step (B) in an aeration tank including a mixture of suspended solids comprising powdered activated carbon and activated sludge mixed with the gas liquor; and (D) adding an iron salt to the gas liquor from step (C) to cause a coagulation and a sedimentation.
Claim 3
Dependent Claim
24 words
The method of claim 1, wherein the content of ammonia in the gas liquor is reduced to 800 to 1,000 ppm in step (A).
Claim 4
Dependent Claim
22 words
The method of claim 1, wherein the COD Mn of the gas liquor is reduced by 30 to 90% in step (B).
Claim 5
Dependent Claim
64 words
The method of claim 1, wherein the treatment in step (B) is carried out in a suspension -type aeration tank in which the concentration of activated sludge is about 2,000 to about 5,000 ppm, the pH is about 6.0 to about 7.5, the amount of dissolved oxygen is about 1 to about 5 ppm, and the temperature is about 25 to about 35° C.
Claim 6
Dependent Claim
85 words
The method of claim 1, wherein the treatment in step (B) is carried out in a fixed bed reaction type aeration tank in which the volume load is about 4 to about 8 kg COD Mn /m 3 day, the surface area load is about 200 to about 400 g COD Mn /m 2 day, the pH is about 6.0 to about 7.5, the amount of dissolved oxygen is about 2 to about 7 ppm, and the temperature is about 25 to about 35° C.
Claim 7
Dependent Claim
24 words
The method of claim 1, wherein the activated carbon used in step (C) has a particle size of about 150 to about 400 mesh.
Claim 8
Dependent Claim
49 words
The method of claim 1, wherein in step (C), the amount of activated sludge is about 2,000 to about 5,000 mg/liter, the amount of activated carbon is about 10,000 to about 50,000 mg/liter, and the weight ratio of activated sludge to activated carbon is about 1:2 to about 1:20.
Claim 9
Dependent Claim
47 words
The method of claim 1, wherein the treatment in step (C) is carried out at a temperature of about 20 to about 40° C. and a pH of about 6 to about 7.5 while maintaining the amount of dissolved oxygen at about 2 to about 6 ppm.
Claim 10
Dependent Claim
44 words
The method of claim 1, wherein in step (D), a ferric salt is added to the gas liquor, and the pH of the gas liquor is adjusted to about 5 to about 7 with an alkali, thereby to sediment cyanide ion as Berlin blue.
Claim 11
Dependent Claim
20 words
The method of claim 9, wherein the ferric salt is FeCl 3 or Fe 2 (SO 4 ) 3 .
Claim 12
Dependent Claim
75 words
The method of claim 1, wherein step (D) comprises adding a ferrous salt to the gas liquor to convert cyanide ion in the gas liquor to a sediment of ferrous ferrocyanide and insoluble Turnbull's blue, adjusting the pH of the gas liquor to about 7.5 to about 9.5, and adding a ferric salt to the gas liquor to precipitate [Fe(CN) 6 ] 4- in the liquor produced on adjustment of pH as insoluble Berlin blue.
Claim 13
Dependent Claim
31 words
The method of claim 11, wherein the ferrous salt is FeCl 2 or FeSO 4 , and the ferric salt is FeCl 3 or Fe 2 (SO 4 ) 3 .
Claim 14
Dependent Claim
94 words
The method of claim 11, wherein the amount of the ferrous salt is such that the Fe II in the salt is within the range shown by x' calculated by the following equations, y = 0.213x - 3.8 x' = x ± 25 mg/l wherein y is the concentration in mg/l of cyanide ion in the influent liquor, x is the amount in mg/l of Fe II in the ferrous salt, and the amount of the ferric salt is determined such that the Fe III /Fe II weight ratio is about 0.5 to 3.
Claim 15
Dependent Claim
27 words
The method of claim 1, wherein the method includes recovering the activated carbon used in step (C), regenerating the recovered activated carbon and recycling the activated carbon.
Claim 16
Dependent Claim
22 words
The method of claim 14, wherein said regeneration treatment of said activated carbon is carried out by a wet air oxidation method.
Claim 17
Dependent Claim
28 words
The method of claim 1, wherein the precipitate produced by adding the ferrous salt is separated and removed from the gas liquor before the adjustment of the pH.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-01-01 | 1982-07-03 | 1983-01-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-01-01 | 1986-07-03 | 1987-01-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-01-01 | 1990-07-03 | 1991-01-02 | $7700.00 | Window Closed / Lapsed |