US4915928A
Expired / Lapsed
US
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Process for removing selenium from wastewater effluent
Assignee: Chevron USA Inc
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Filing: 1989-03-31
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Granted: 1990-04-10
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Expires: 2009-03-31
Abstract
Abstract Disclosed is a process for removing selenium from wastewater effluent. The processd includes the steps of; (i) contacting a selenide containing wastewater and a strong-base anion exchange resin to absorb selenide on the resin; (ii) eluting the ion exchange resin with an eluant which is effective for stripping selenide therefrom; and (iii) recovering elemental selenium from the selenide containing eluate resulting from step (ii). Also disclosed is a process for regenerating the ion exchange resin by treatment of the resin with an acidic chlorate solution.
Inventors
- 👤 Paul J. Marcantonio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:19
CPC Classifications
B; B01; B01J; B01J49/00; B01J49/05; B01J49/07; B01J41/00; B01J41/04; B01J41/05; Y; Y10; Y10S; Y10S423/00; Y10S423/09; Y10S423/14
Claims Analysis
Total Claims: 37
Claim 1
Independent Claim
60 words
A process for removing selenium from wastewater effluent comprising the steps of; (i) contacting a selenide containing wastewater and a strong-base anion exchange resin to adsorb selenide on the resin; (ii) eluting the ion exchange resin with an eluant which is effective for stripping selenide therefrom; and (iii) recovering elemental selenium from the selenide containing eluate resulting from step (ii).
Claim 2
Dependent Claim
60 words
A process for removing selenium from wastewater effluent comprising the steps of; (i) contacting a selenide containing wastewater and a strong-base anion exchange resin to adsorb selenide on the resin; (ii) eluting the ion exchange resin with an eluant which is effective for stripping selenide therefrom; and (iii) recovering elemental selenium from the selenide containing eluate resulting from step (ii).
Claim 3
Dependent Claim
24 words
A process according to claim 1 further comprising (iv) regenerating the ion exchange resin by treatment of the resin with an acidic chlorate solution.
Claim 4
Dependent Claim
32 words
A process according to claim 1 wherein elemental selenium is recovered from the selenide containing eluate using at least one of (a) acidification of the eluate and (b) oxygenation of the eluate.
Claim 5
Dependent Claim
21 words
A process according to claim 3 wherein the eluate is subjected to both acidification and oxygenation to recover elemental selenium therefrom.
Claim 6
Dependent Claim
34 words
A process according to claim 4 wherein the eluate is acidified to obtain a pH ranging from about 1 to about 7, and elemental selenium is recovered from a flotation cell or by filtering.
Claim 7
Dependent Claim
19 words
A process according to claim 1 wherein the eluant contains at least one of sodium chloride and sodium hydroxide.
Claim 8
Dependent Claim
16 words
A process according to claim 1 wherein the eluant contains both sodium chloride and sodium hydroxide.
Claim 9
Dependent Claim
27 words
A process according to claim 7 wherein the eluant contains from about 1 to about 10% sodium chloride and from about 0.1 to about 2% sodium hydroxide.
Claim 10
Dependent Claim
27 words
A process according to claim 8 wherein the eluant contains from about 3 to about 5% sodium chloride and from about 0.3 to about 0.7% sodium hydroxide.
Claim 11
Dependent Claim
22 words
A process according to claim 1 wherein the eluant is heated to a temperature ranging from about 30° to about 50° C.
Claim 12
Dependent Claim
22 words
A process according to claim 10 wherein the eluant is heated to a temperature ranging from about 45° to about 50° C.
Claim 13
Dependent Claim
23 words
A process according to claim 1 wherein elution is carried out at a rate of about 0.1 to about 0.8 gpm/ft 3 .
Claim 14
Dependent Claim
23 words
A process according to claim 12 wherein elution is carried out at a rate of about 0.2 to about 0.3 gpm/ft 3 .
Claim 15
Dependent Claim
28 words
A process according to claim 2 wherein the acidic chlorate solution contains from about 1 to about 15% sodium chlorate and about 0.5 to about 10% hydrochloric acid.
Claim 16
Dependent Claim
20 words
A process according to claim 2 wherein the solution has a temperature ranging from about 35° to about 60° C.
Claim 17
Dependent Claim
20 words
A process according to claim 15 wherein the solution has a temperature ranging from about 45° to about 50° C.
Claim 18
Dependent Claim
25 words
A process for regenerating a stron-base anion exchange resin used to remove selenium from wastewater effluent comprising treating the resin with an acidic chlorate solution.
Claim 19
Dependent Claim
25 words
A process for regenerating a stron-base anion exchange resin used to remove selenium from wastewater effluent comprising treating the resin with an acidic chlorate solution.
Claim 20
Dependent Claim
35 words
A process according to claim 17, said strong-base anion exchange resin having been contacted with a selenide containing wastewater to adsorb selenide on the resin, and eluted with an eluant effective for stripping selenide therefrom.
Claim 21
Dependent Claim
28 words
A process according to claim 18, wherein the acidic chlorate solution contains from about 1 to about 8% sodium chlorate and about 0.5 to about 5% hydrochloric acid.
Claim 22
Dependent Claim
20 words
A process according to claim 18, wherein the solution has a temperature ranging from about 40° to about 55° C.
Claim 23
Dependent Claim
20 words
A process according to claim 20, wherein the solution has a temperature ranging from about 45° to about 50° C.
Claim 24
Dependent Claim
102 words
A process for removing selenium from petroleum refining wastewater comprising the steps of; (i) stripping sulfur from selenide containing sour water produced by petroleum refining; (ii) subjecting the stripped sour water to ion exchange treatment with a strong-base anion exchange resin to adsorb selenide on the resin; (iii) eluting the ion exchange resin with an eluant for stripping selenide therefrom, said eluant containing at least one of sodium chloride and sodium hydroxide; and (iv) recovering elemental selenium from the selenide containing eluate resulting from step (iii) using at least one of (a) acidification of the eluate and (b) oxygenation of the eluate.
Claim 25
Dependent Claim
102 words
A process for removing selenium from petroleum refining wastewater comprising the steps of; (i) stripping sulfur from selenide containing sour water produced by petroleum refining; (ii) subjecting the stripped sour water to ion exchange treatment with a strong-base anion exchange resin to adsorb selenide on the resin; (iii) eluting the ion exchange resin with an eluant for stripping selenide therefrom, said eluant containing at least one of sodium chloride and sodium hydroxide; and (iv) recovering elemental selenium from the selenide containing eluate resulting from step (iii) using at least one of (a) acidification of the eluate and (b) oxygenation of the eluate.
Claim 26
Dependent Claim
24 words
A process according to claim 22, further comprising (iv) regenerating the ion exchange resin by treatment of the resin with an acidic chlorate solution.
Claim 27
Dependent Claim
22 words
A process according to claim 22, wherein the 2 eluate is subjected to both acidification and oxygenation to recover elemental selenium therefrom.
Claim 28
Dependent Claim
27 words
A process according to claim 24, wherein the eluate is acidified to obtain a pH ranging from about 3 to about 5, and elemental selenium is recovered.
Claim 29
Dependent Claim
16 words
A process according to claim 22 wherein the eluant contains both sodium chloride and sodium hydroxide.
Claim 30
Dependent Claim
27 words
A process according to claim 26, wherein the eluant contains from about 3 to about 5% sodium chloride and from about 0.3 to about 0.7% sodium hydroxide.
Claim 31
Dependent Claim
22 words
A process according to claim 22, wherein the eluant is heated to a temperature ranging from about 45° to about 50° C.
Claim 32
Dependent Claim
23 words
A process according to claim 22, wherein elution is carried out at a rate of about 0.2 to about 0.3 gpm/ft 3 .
Claim 33
Dependent Claim
28 words
A process according to claim 23, wherein the acidic chlorate solution contains from about 2 to about 4% sodium chlorate and about 0.5 to about 2% hydrochloric acid.
Claim 34
Dependent Claim
20 words
A process according to claim 23, wherein the solution has a temperature ranging from about 45° to about 50° C.
Claim 35
Dependent Claim
32 words
A process for regenerating a strong-base anion exchange resin used to remove selenide from selenide containing sour water produced by petroleum refining wherein the resin is treated with an acidic chlorate solution.
Claim 36
Dependent Claim
32 words
A process for regenerating a strong-base anion exchange resin used to remove selenide from selenide containing sour water produced by petroleum refining wherein the resin is treated with an acidic chlorate solution.
Claim 37
Dependent Claim
46 words
A process according to claim 32, said strong-base anion exchange resin having been contacted with a selenide containing stripped sour water to adsorb selenide on the resin, and eluted with an eluant containing at least one of sodium chloride and sodium hydroxide to strip selenide therefrom.
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) | 1993-04-09 | 1993-10-09 | 1994-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-04-09 | 1997-10-09 | 1998-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-04-09 | 2001-10-09 | 2002-04-10 | $7700.00 | Window Closed / Lapsed |