Photocatalytic oxidation of organics using a porous titanium dioxide membrane and an efficient oxidant
First Claim
1. A process for oxidizing organic contaminants, comprising the steps of:
- providing a fluid containing the organic contaminants over a photocatalyst disposed on a first surface of a porous substrate having pores therethrough to a second surface;
providing an oxidant to the second surface and through the pores of the porous substrate into contact with the photocatalyst on the first surface; and
exposing the photocatalyst to ultraviolet light.
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Accused Products
Abstract
A method and apparatus for mineralizing organic contaminants in water or air provides photochemical oxidation in a unique two-phase or three-phase boundary system formed in each pore of a TiO2 membrane in a photocatalytic reactor. In the three-phase system, gaseous oxidant, liquid contaminant, and solid semiconductor photocatalyst meet and engage in an efficient oxidation reaction. The porous membrane has pores which have a region wherein the meniscus of the liquid varies from the molecular diameter of water to that o f a capillary tube resulting in a diffusion layer that is several orders of magnitude smaller than the closest known reactors. The photocatalytic reactor operates effectively at ambient temperature and low pressures.
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Citations
44 Claims
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1. A process for oxidizing organic contaminants, comprising the steps of:
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providing a fluid containing the organic contaminants over a photocatalyst disposed on a first surface of a porous substrate having pores therethrough to a second surface; providing an oxidant to the second surface and through the pores of the porous substrate into contact with the photocatalyst on the first surface; and
exposing the photocatalyst to ultraviolet light. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 43, 44)
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13. An apparatus for oxidizing organic contaminants, comprising:
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a porous substrate comprising a first photocatalytic surface, a second surface and pores extending therethrough; means for flowing a fluid containing organic contaminants over the first photocatalytic surface; means for flowing an oxidant through the pores of the porous substrate into the flowing fluid; and means for exposing the photocatalytic surface to ultraviolet light. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. An apparatus for oxidizing organic contaminants, comprising:
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a porous substrate having a photocatalyst disposed on one surface and pores extending therethrough; a fluid cell adjacent the photocatalyst surface, the fluid cell comprising a fluid inlet, a fluid outlet, and a ultraviolet transmission surface positioned to expose the porous photocatalyst surface; and an oxidant cell adjacent a second, opposed surface of the porous substrate, the oxidant cell comprising an oxidant inlet. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36)
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37. A process for oxidizing organic contaminants, comprising the steps of:
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introducing the organic contaminants over a first surface of a porous photocatalyst; introducing an oxidant over an opposing surface of the porous photocatalyst; and contacting the organic contaminants with the oxidant adjacent the first surface. - View Dependent Claims (38)
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39. A photocatalytic reactor for oxidizing organic contaminants, comprising:
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a substrate having first and second opposed faces and pores communicating between the faces, wherein at least the first face is photocatalytic; a fluid cell communicating with the first face and allowing transmission of ultraviolet light onto the first face; and an oxidant cell communicating with the second face. - View Dependent Claims (40, 41, 42)
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Specification