US4737289A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for wastewater treatment
Assignee: Radian International LLC
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Filing: 1986-11-26
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Granted: 1988-04-12
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Expires: 2006-11-26
Abstract
Abstract Free cyanide-containing wastewater is treated to destroy the free cyanide content thereof by the step of treating said water with sulfur in the form of polysulfide in an integrated process wherein thiocyanate is also eliminated to produce a non-hazardous wastewater effluent and treating the wastewater in a second step with cultures of bacteria of the genus Thiobacillus in combination with nitrifying bacteria which oxidize ammonia to nitrite and nitrite to nitrate. The first step is preferably carried out in the presence of added metallic zinc.
Inventors
- 👤 Frank J. Castaldi
- 👤 Timothy W. Trofe
- 👤 Gordon C. Page
- 👤 Kevin M. Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:07
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/34; C02F3/345; C02F3/02; C02F3/12; C02F3/1205; C02F3/1215; C02F2101/00; C02F2101/10; C02F2101/16; C02F2101/18; Y; Y02; Y02W; Y02W10/00; Y02W10/10; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/903; Y10S210/904
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
112 words
An integrated process for treating a wastewater containing free cyanide to convert said cyanide to thiocyanate and to eliminate said thiocyanate to produce a nonhazardous wastewater effluent which comprises the steps of treating a wastewater containing free cyanide with sulfur in the form of polysulfide at a pH in the range of 9.2 to 10, in a weight ratio of polysulfide to cyanide ranging from 1:1 to 4:1, thereafter adjusting the pH to a range of 6.7 to 7.2 and treating the resultant wastewater with a treating agent consisting essentially of cultures of bacteria of the genus Thiobacillus in combination with nitrifying bacteria which oxidize ammonia to nitrite and nitrite to nitrate.
Claim 2
Dependent Claim
112 words
An integrated process for treating a wastewater containing free cyanide to convert said cyanide to thiocyanate and to eliminate said thiocyanate to produce a nonhazardous wastewater effluent which comprises the steps of treating a wastewater containing free cyanide with sulfur in the form of polysulfide at a pH in the range of 9.2 to 10, in a weight ratio of polysulfide to cyanide ranging from 1:1 to 4:1, thereafter adjusting the pH to a range of 6.7 to 7.2 and treating the resultant wastewater with a treating agent consisting essentially of cultures of bacteria of the genus Thiobacillus in combination with nitrifying bacteria which oxidize ammonia to nitrite and nitrite to nitrate.
Claim 3
Dependent Claim
18 words
A process as defined in claim 1, wherein the nitrifying bacteria comprise the family of chemoautotrophic bacteria, Nitrobacteraceae.
References Cited (Backward Citations)
JPS5378658A
Cited
JPS5579093A
Cited
JPS5584598A
Cited
JPS5721988A
Cited
US4537686A
Cited
US4508683A
Cited
US4530768A
Cited
JPS60251985A
Cited
US4615873A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-12 | 1991-10-12 | 1992-04-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-12 | 1995-10-12 | 1996-04-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-12 | 1999-10-12 | 2000-04-12 | $7700.00 | Window Closed / Lapsed |