System and method for photocatalytic treatment of contaminated media

• US 6,398,971 B1
• Filed: 06/02/2000
• Issued: 06/04/2002
• Est. Priority Date: 09/10/1997
• Status: Expired due to Term

• Current Assignee: Purifics Environmental Technologies Incorporated
• Original Assignee: Purifics Environmental Technologies Incorporated
• Inventors: Butters, Brian E., Powell, Anthony Leonard
• Primary Examiner(s): Barry, Chester T.
• Application Number:
  US09/587,625
• Time in Patent Office: 732 Days
• Field of Search: 210/748
• US Class Current: 210/748.14
• CPC Class Codes: B01D 2255/802 Photocatalytic
• CPC Class Codes: B01D 53/14 by absorption
• CPC Class Codes: B01D 53/86 Catalytic processes
• CPC Class Codes: B01D 53/8668 Removing organic compounds not provided for in B01D53/8603 - B01D53/8665
• CPC Class Codes: B09C 1/02 Extraction using liquids, e.g. washing, leaching , flotation
• CPC Class Codes: C02F 1/32 with ultraviolet light
• CPC Class Codes: C02F 1/325 Irradiation devices or lamp constructions
• CPC Class Codes: C02F 1/725 by catalytic oxidation
• CPC Class Codes: C02F 2103/18 from the purification of gaseous effluents
• CPC Class Codes: C02F 2305/10 Photocatalysts

Abstract

A system for treating contaminated media is provided. In the process, contaminants are removed from the media using a photocatalytic process operating in an aqueous phase.

Claims

1. A method for treating contaminants gaseous media comprising:

transferring contaminants from a gaseous media to a liquid media; and

treating the liquid media by aqueous photocatalysis to cause the contaminants in the liquid media to undergo a photocatalytic reaction.

2. The method of claim 1 wherein transferring contaminants from a gaseous media to a liquid media further comprises:

causing the gaseous media to flow through an adsorbent so that the contaminants in the gaseous media may be adsorbed onto the surface of the adsorbent; and

exposing the adsorbent to a solvent to remove the contaminants from the surface of the adsorbent.

3. The method of claim 1 wherein transferring contaminants from a gaseous media to a liquid media further comprises:

causing the gaseous media to flow through an adsorbent so that the contaminants in the gaseous media may be adsorbed onto the surface of the adsorbent; and

exposing the adsorbent to steam to remove the contaminants from the surface of the adsorbent.

4. The method of claim 1 wherein transferring contaminants from a gaseous media to a liquid media further comprises:

causing the gaseous media to flow through first adsorbent so that the contaminants may be adsorbed onto the surface of the first adsorbent;

exposing the first adsorbent to steam to remove the contaminants from the surface of the first adsorbent;

causing the gaseous media to flow through second adsorbent while the first adsorbent is being exposed to steam; and

exposing the second adsorbent to steam to remove the contaminants from the surface of the second adsorbent while the gaseous media is flowing through the first adsorbent.

5. The method of claim 1 wherein transferring contaminants from a gaseous media to a liquid media further comprises:

causing the gaseous media to flow through an adsorbent so that the contaminants may be adsorbed onto the surface of the adsorbent;

exposing the adsorbent to steam to remove the contaminants from the surface of the adsorbent;

condensing the steam with a condenser to form a condensate with dissolved and undissolved contaminants; and

removing the liquid media containing dissolved contaminants from the condenser.

6. The method of claim 5 further comprising removing undissolved contaminants from the condensate.

7. The method of claim 1 wherein transferring contaminants from a gaseous media to a liquid media further comprises:

injecting the gaseous media into a scrubber; and

scrubbing the gaseous media with the liquid media.

8. The method of claim 7, wherein the scrubber contains a scrubber field, and wherein the pH of the scrubber field is regulated so that the contaminants are substantially precluded from adhering to the surface of a photocatalyst.

9. The method of claim 1, wherein transferring the contaminants from a gaseous media to a liquid media comprises:

circulating the gaseous media through a gas scrubber in a manner so as to transfer contaminants from a gaseous media to the liquid media; and

removing the liquid media containing the contaminants from the gas scrubber.

10. The method of claim 1 comprising adding an irreversible electron acceptor to the photocatalytic slurry.

11. A method for treating contaminated media comprising:

injecting contaminated gaseous media into a vessel;

adding a photocatalytic slurry to the vessel and effecting a transfer of contaminants from the contaminated gaseous media to the photocatalytic slurry; and

exposing the photocatalytic slurry to electromagnetic radiation.

12. The method of claim 11 further comprising adding a conditioner to the photocatalytic slurry.

13. The method of claim 12 further comprising adding an irreversible electron acceptor to the photocatalytic slurry.

14. The method of claim 11 wherein exposing the photocatalytic slurry with the adsorbed gaseous contaminants to electromagnetic radiation comprises exposing the photocatalytic slurry with the adsorbed gaseous contaminants to ultraviolet radiation.