You’re using a public version of DrugPatentWatch with 5 free searches available | Register to unlock more free searches. CREATE FREE ACCOUNT

Last Updated: March 28, 2024

Claims for Patent: 5,904,832


✉ Email this page to a colleague

« Back to Dashboard


Summary for Patent: 5,904,832
Title: Regeneration of active carbon and polymeric adsorbents
Abstract:Method for the regeneration of active carbon and polymeric adsorbents having oxidizable, organic pollutants adsorbed thereon by electrochemical and chemical means and apparatus therefor. The method involves a desorption step and a decomposition step. Desorption is accomplished in one embodiment by flowing an aqueous stream at a preselected pH through the adsorbent material. Generally, decomposition is accomplished by contacting an aqueous stream containing an organic pollutant with hydroxyl radicals. Sequential or simultaneous desorption and decomposition can also take place during electrolysis in an electrolytic cell. During decomposition the active carbon can be made a carbon bed electrode of the cell. Electrolysis to produce peroxide can take place in the presence of a transition metal or a chelate of a transition metal while feeding an oxygen containing gas to the electrolysis cell.
Inventor(s): Clifford; Arthur L. (Everett, CA), Dong; Dennis F. (Kingston, CA), Mumby; Timothy A. (Kingston, CA), Rogers; Derek J. (Kingston, CA)
Assignee: Huron Tech Canada, Inc. (Kingston, CA)
Application Number:08/810,688
Patent Claims:1. In a process for regenerating the adsorptive capacity of a mass of an adsorbent material comprising a conductive adsorbent or a non-conductive, synthetic adsorbent and an oxidizable, organic material, the improvement wherein said oxidizable, organic material is desorbed from said adsorbent material and substantially decomposed in a batch or cyclic process comprising:

A) in a desorption stage, passing a first aqueous stream at a preselected pH to said adsorbent material, selected from the group consisting of activated carbon, polymeric adsorbents, and carbonaceous adsorbents, to desorb said oxidizable, organic material therefrom and produce a second aqueous stream comprising said organic material and

B) passing said second aqueous stream to a decomposition stage and contacting said aqueous stream with an oxidant.

2. The process of claim 1 wherein in said desorption stage, said mass of adsorbent material comprises carbon, said first aqueous stream is acidic or alkaline, and said carbon is positively or negatively polarized.

3. The process of claim 1 wherein said decomposition stage comprises an electrolytic cell or a vessel comprising hydroxyl radicals produced by reacting hydrogen peroxide with a reactant selected from the group consisting of transition metal ions, ultraviolet light, and ozone or hydroxyl radicals produced by reacting ultraviolet light and ozone.

4. The process of claim 3 wherein said second aqueous stream is made the electrolyte of an electrolytic cell in which said hydroxyl radicals are produced at a pH of about 1 to about 4 or produced at a pH of about 8 or higher in the presence of a chelating agent.

5. The process of claim 4 wherein said electrolyte comprises hydrogen peroxide, a transition metal or ions thereof, and hydroxyl radicals and electrolysis is conducted in said cell while passing an oxygen containing gas to said cell.

6. The process of claim 5 whereby desorption of said organic material comprises passing said first aqueous stream at an alkaline pH to said adsorbent material and wherein said adsorbent material comprises carbon and said oxidizable, organic material is selected from the group consisting of halogenated and non-halogenated organic compounds, fuel hydrocarbons, and pesticides.

7. An apparatus for regeneration of the adsorptive capacity of an adsorbent material comprising a conductive adsorbent or a non-conductive, synthetic adsorbent and an oxidizable, organic material, said apparatus comprising means for desorbing and means for decomposing an oxidizable, organic material from said adsorbent material,

said means for desorbing said organic material comprising a desorption vessel for passing a first aqueous stream at a preselected pH to said adsorbent material to desorb said organic material therefrom, thereby producing a second aqueous stream,

said means for decomposing said organic material comprising a decomposition vessel for contacting said second aqueous stream with hydroxyl radicals, an oxidant produced in an electrolytic cell for water electrolysis or produced in an electrolytic cell for the production of a peroxide or an oxidant, and

wherein said adsorbent material is selected from the group consisting of carbon, polymeric adsorbents, and carbonaceous adsorbents and said hydroxyl radicals are produced by reacting hydrogen peroxide with a reactant selected from the group consisting of transition metal ions, ultraviolet light, and ozone or produced by reacting ultraviolet light and ozone.

8. The apparatus of claim 7 wherein said means for decomposing said organic material comprises an electrolytic cell comprising:

A) an anode, a cathode, and an aqueous electrolyte maintained at a pH of about 1 to about 4 comprising hydrogen peroxide, transition metal ions, while conducting electrolysis and feeding an oxygen containing gas to said cell or

B) an anode, a cathode, and an aqueous electrolyte comprising a complex of a transition metal and a chelating agent wherein said electrolyte is maintained at a pH of about 8 or higher while conducting electrolysis and feeding an oxygen containing gas to said cell.

9. The apparatus of claim 8 wherein said cathode consists of carbon and said chelating agent is selected from the group consisting of nitriloacetic acid; diethylenetriaminepentaacetic acid and salts thereof; hydroxyethylethylenediaminetriacetic acid and salts thereof; diethylenetriaminepentamethylene phosphoric acid and salts thereof; cyclohexylenedintrilotetraacetic acid and salts thereof; ethylenebis(oxyethylenenitrilo)tetraacetic acid and salts thereof; hemin; and ethylenediaminetetraacetic acid.

10. In a process for regenerating the adsorptive capacity of an adsorbent material comprising a conductive adsorbent or a non-conductive, synthetic adsorbent and an oxidizable, organic material, the improvement wherein said organic material is desorbed from said adsorbent material and substantially decomposed, in a process comprising:

A) in a first stage, contacting said adsorbent material with a first aqueous stream at a preselected pH to desorb said oxidizable, organic material therefrom and produce a second aqueous stream comprising said organic material,

B) in a second stage, contacting said second aqueous stream comprising said organic material with an oxidant produced in an electrolytic cell for water electrolysis or produced in an electrolytic cell for the production of a peroxide or an oxidant comprising hydroxyl radicals to decompose said organic material, and

wherein said first and second stages are operated simultaneously.

11. The process of claim 10 wherein in said first stage, said adsorbent material comprises carbon, said first aqueous stream is acidic or alkaline, and said carbon is polarized positively or negatively.

12. The process of claim 10 wherein said adsorbent material is selected from the group consisting of a carbon, a polymeric adsorbent, and a carbonaceous adsorbent, and said hydroxyl radicals are produced by reacting hydrogen peroxide with a reactant selected from the group consisting of transition metal ions, ultraviolet light, and ozone or produced by reacting ultraviolet light and ozone.

13. The process of claim 12 wherein said second aqueous stream is made the electrolyte of an electrolytic cell in which said hydroxyl radicals are produced at a pH of about 1 to about 4 or at a pH of about 8 or higher in the presence of a chelating agent.

14. The process of claim 13 wherein said electrolyte comprises hydrogen peroxide, a transition metal or ions thereof, and hydroxyl radicals and electrolysis is conducted in said cell while passing an oxygen containing gas to said cell.

15. The process of claim 14 whereby desorption of said organic material is accomplished by passing said first aqueous stream at an alkaline pH to said adsorbent material and wherein said adsorbent material is carbon and said oxidizable, organic material is selected from the group consisting of halogenated and non-halogenated organic compounds, fuel hydrocarbons, and pesticides.

16. A process for decomposing an oxidizable organic material in a contaminated aqueous waste stream comprising:

(A) contacting said aqueous waste stream with an oxidant comprising hydroxyl radicals to decompose said organic material wherein said oxidant is produced in an electrolytic cell for water electrolysis or said oxidant is produced in an electrolytic cell for the production of a peroxide and

(B) wherein said hydroxyl radicals are produced in said electrolytic cell having an aqueous electrolyte at a pH of about 1 to about 4 or a pH of about 8 or higher in the presence of a chelating agent.

17. The process of claim 16 wherein said electrolyte comprises hydrogen peroxide, a transition metal or ions thereof, and hydroxyl radicals and electrolysis is conducted in said cell while passing an oxygen containing gas to said cell.

18. The process of claim 17 wherein said chelating agent is selected from the group consisting of nitriloacetic acid; diethylenetriaminepentacetic acid and salts thereof; hydroxyethylethylenediaminetriacetic acid and salts thereof; diethylenetriaminepentamethylene phosphoric acid and salts thereof; cyclohexylenedinitrilotetraacetic acid and salts thereof; ethylenebis (oxyethylenenitrilo)tetraacetic acid and salts thereof; hemin; and ethylenediaminetetraacetic acid.

19. The process of claim 17 wherein said oxidizable, organic material is selected from the group consisting of halogenated and non-halogenated organic compounds, fuel hydrocarbons, and pesticides.

Make Better Decisions: Try a trial or see plans & pricing

Drugs may be covered by multiple patents or regulatory protections. All trademarks and applicant names are the property of their respective owners or licensors. Although great care is taken in the proper and correct provision of this service, thinkBiotech LLC does not accept any responsibility for possible consequences of errors or omissions in the provided data. The data presented herein is for information purposes only. There is no warranty that the data contained herein is error free. thinkBiotech performs no independent verification of facts as provided by public sources nor are attempts made to provide legal or investing advice. Any reliance on data provided herein is done solely at the discretion of the user. Users of this service are advised to seek professional advice and independent confirmation before considering acting on any of the provided information. thinkBiotech LLC reserves the right to amend, extend or withdraw any part or all of the offered service without notice.