Systems for catalytically removing oxidized contaminants from a fluid and related methods
AssigneeArizona Board of Regents on behalf of Arizona State University
InventorsChen Zhou, Bruce Rittman, Dandan Zhou, Yihao Luo, Min Long, Chenwei Zheng
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Abstract
The present invention relates to systems and methods for catalytic removal of oxidized contaminants (for example, nitrite, chromate, chlorate, trichloroethene, CFC-11, 4-nonylphenol, RDX, and perfluorooctanoate) from water and wastewater. In some aspects, the catalytic method of removing oxidized contaminants comprises using precious metal nanoparticles as catalysts to reduce the oxidized contaminants.
Claims19
A method of establishing a catalyst film for long-term removal of oxidized contaminants from a fluid, the method comprising:
- providing a non-porous gas transfer membrane, wherein the non-porous gas transfer membrane comprises a gas-phase side and a liquid-phase side;
- contacting the liquid-phase side of the non-porous gas transfer membrane with a precious metal medium, the precious metal medium comprising a precious metal salt and a solvent;
- and
- contacting the gas-phase side of the non-porous gas transfer membrane with hydrogen (H2) gas at a sufficient partial pressure to convert at least 90% of the precious metal salt in the precious metal medium to an elemental form in the form of nanoparticles with a mean diameter of less than 5 nm;
- wherein the elemental form of the precious metal is deposed on the liquid-phase side of the non-porous gas transfer membrane thereby forming the catalyst film.
A method of removing oxidized contaminants from a fluid, the method comprising:
- establishing a catalyst film, the catalyst film comprising precious metal nanoparticles on a non-porous gas transfer membrane;
- contacting a fluid containing oxidized contaminants with the catalyst film;
- and
- contacting the catalyst film with hydrogen (H2) gas at a sufficient partial pressure to reduce the oxidized contaminants;
- wherein the oxidized contaminants are selected from at least one member of the group consisting of:
- chlorophenols, 2,4-dichlorophenoxyacetic acid, 3,6-dichloro-2-methoxybenzoic acid, 1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine, 3,5-dibromo-4-hydroxybenzonitrile, trichloroacetic acid, trichloroacetonitrile, NDMA, bromochloroiodomethane, chloroform, CFC-11, CFC-12, CFC-113, phenol, nitrophenols, PFAS 1,3,5-Trinitro-1,3,5-triazinane, 1,3,5,7-Tetranitro-1,3,5,7-tetrazoctane, and TNT.
A method of establishing a catalyst film for long-term removal of oxidized contaminants from a fluid, the method comprising:
- providing a non-porous gas transfer membrane, wherein the non-porous gas transfer membrane comprises a gas-phase side and a liquid-phase side;
- contacting the liquid-phase side of the non-porous gas transfer membrane with a precious metal medium, the precious metal medium comprising a precious metal salt and a solvent;
- and
- contacting the gas-phase side of the non-porous gas transfer membrane with hydrogen (H2) gas at a sufficient partial pressure to convert at least 90% of the precious metal salt in the precious metal medium to an elemental form;
- wherein:
- the oxidized contaminants are selected from at least one member of the group consisting of:
- chlorophenols, 2,4-dichlorophenoxyacetic acid, 3,6-dichloro-2-methoxybenzoic acid, 1-chloro-3-ethylamino-5-isopropylamino-2,4,6-triazine, 3,5-dibromo-4-hydroxybenzonitrile, trichloroacetic acid, trichloroacetonitrile, NDMA, bromochloroiodomethane, chloroform, CFC-11, CFC-12, CFC-113, phenol, nitrophenols, PFAS, 1,3,5-Trinitro-1,3,5-triazinane, 1,3,5,7-Tetranitro-1,3,5,7-tetrazoctane, and TNT;
- and
- the elemental form of the precious metal is in the form of a nanoparticle and is deposed on the liquid-phase side of the non-porous gas transfer membrane.
Dependencies are inferred from the claim text.