# US 2016/0355409 A1 · Method for disinfecting a fluid with a palladium-doped tungsten trioxide photo-catalyst

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- Number: US 2016/0355409 A1
- Document ID: US20160355409A1
- Status: Published application
- Kind: A1
- Application number: 15/136,399
- Filed: 2016-04-22
- Published: 2016-12-08
- Earliest claimed: 2015-06-08
- Assignees: King Fahd University of Petroleum and Minerals
- Applicants: King Fahd University of Petroleum and Minerals
- Inventors: Muhammad Ashraf GONDAL; Mohamed A. Dastageer; Amjad B. Khalil; Rashid Gulam Siddique; Umair Baig
- Web page: https://patentgrep.com/patent/US20160355409A1

## CPC

- C02F 1/32: with ultraviolet light
- C02F 1/725: {by catalytic oxidation}
- C02F 1/281: {using inorganic sorbents}
- C02F 1/283: {using coal, charred products, or inorganic mixtures containing them}
- C02F 1/285: {using synthetic organic sorbents}
- C02F 1/42: by ion-exchange (ion-exchange in general B01J)
- C02F 1/722: {Oxidation by peroxides}
- C02F 1/78: with ozone {(C02F1/4672 takes precedence)}
- C02F 2201/006: Cartridges
- C02F 2201/3222: Units using UV-light emitting diodes [LED]
- C02F 2209/02: Temperature
- C02F 2209/03: Pressure
- C02F 2303/04: Disinfection
- C02F 2305/08: Nanoparticles or nanotubes
- C02F 2305/10: Photocatalysts
- Y02W 10/37: using solar energy
- C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT

## Abstract

The present disclosure relates to a method of disinfecting a fluid comprising at least one live microbial organism. The method includes contacting the fluid comprising the at least one microbial organism with an effective amount of a photo-catalyst while exposing the fluid and the photo-catalyst to light from at least one light source with a wavelength of about 300-550 nm to reduce the number of the at least one live microbial organism to a predetermined level. The photo-catalyst comprises tungsten trioxide nanoparticles doped with palladium nanoparticles, and the palladium nanoparticles are present in an amount of about 0.1-5% of the total weight of the tungsten trioxide nanoparticles and the palladium nanoparticles.

## Claims

### Claim 1

A method of disinfecting a fluid comprising at least one live microbial organism, the method comprising:
contacting the fluid comprising the at least one microbial organism with an effective amount of a photo-catalyst while exposing the fluid and the photo-catalyst to light from at least one light source with a wavelength of about 300-550 nm to reduce the number of the at least one live microbial organism to a predetermined level,
wherein the photo-catalyst comprises tungsten trioxide nanoparticles doped with palladium nanoparticles, and
wherein the palladium nanoparticles are present in an amount of about 0.1-5% of the total weight of the tungsten trioxide nanoparticles and the palladium nanoparticles.

### Claim 2 (depends on 1)

The method of claim 1, wherein the palladium nanoparticles have a spheroid shape with an average particle diameter of about 4-17 nm.

### Claim 3 (depends on 1)

The method of claim 1, wherein the at least one live microbial organism is at least one selected from the group consisting of bacteria, a virus, bacterial spores, protozoa, and fungi.

### Claim 4 (depends on 1)

The method of claim 1, wherein the at least one light source is at least one selected from the group consisting of a laser light source, a light emitting diode, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, a xenon lamp, a fluorescent lamp, an incandescent lamp, a sodium vapor lamp, a halogen lamp, a noble gas discharge, a flame, and sunlight.

### Claim 5 (depends on 1)

The method of claim 1, wherein the tungsten trioxide nanoparticles have an average particle size of 60-100 nm.

### Claim 6 (depends on 1)

The method of claim 1, wherein the tungsten trioxide nanoparticles have a plate and/or cylindrical shape.

### Claim 7 (depends on 1)

The method of claim 1, wherein the tungsten trioxide nanoparticles doped with the palladium nanoparticles have a lower photoluminescence intensity at a wavelength of 400-500 nm than tungsten trioxide nanoparticles which are not doped with palladium nanoparticles.

### Claim 8 (depends on 1)

The method of claim 1, wherein the tungsten trioxide nanoparticles doped with the palladium nanoparticles have a first band gap energy, tungsten trioxide nanoparticles which are not doped with palladium nanoparticles have a second band gap energy, and wherein the difference between the first band gap energy and the second band gap energy is less than 10% of the second band gap energy.

### Claim 9 (depends on 1)

The method of claim 1, wherein the fluid further comprises at least one hydrocarbon, and the live microbial organism is a sulfate-reducing bacterium.

### Claim 10 (depends on 9)

The method of claim 9, wherein the effective amount of the photo-catalyst ranges from about 0.5 mg/ml to 1.5 mg/ml of the fluid.

### Claim 11 (depends on 9)

The method of claim 9, wherein the fluid is treated with at least one selected from the group consisting of oxygen, ozone, and a peroxide before and/or during the contacting and the exposing.

### Claim 12 (depends on 9)

The method of claim 9, wherein the fluid is contacted with the photo-catalyst and exposed to the light at a temperature of about 4-100° C. and a pressure of about 0.1-100 bar.

### Claim 13 (depends on 1)

The method of claim 1, wherein the photo-catalyst is disposed on a surface of a substrate to form a photo-catalyst/substrate composite.

### Claim 14 (depends on 13)

The method of claim 13, wherein the substrate comprises at least one selected from the group consisting of glass, stone, masonry, a metal, wood, a plastic, concrete, fibers, textiles, yarns, a ceramic, alumina, carbon, silica, an organic polymer, silicon carbide, silicon nitride, boron nitride, zirconium, and tungsten carbide.

### Claim 15 (depends on 13)

The method of claim 13, wherein the photo-catalyst/substrate composite is disposed in a fixed bed reactor or fluidized bed reactor and the contacting involves passing the fluid through the fixed bed reactor or fluidized bed reactor.

### Claim 16 (depends on 15)

The method of claim 15, wherein the fixed bed reactor comprises a cartridge.

### Claim 17 (depends on 15)

The method of claim 15, wherein the fixed bed reactor or fluidized reactor further comprises at least one adsorbent selected from the group consisting of activated carbon, graphite, activated alumina, a molecular sieve, aluminophosphate material, silicoaluminophosphate material, zeolites, faujasite, clinoptilolite, mordenite, metal-exchanged silicoaluminophosphate, uni-polar resin, bi-polar resin, aromatic cross-linked polystyrenic matrix, brominated aromatic matrix, acrylic polymer, acrylic copolymer, methacrylic polymer, methacrylic copolymer, hydroxyalkyl acrylate, hydroxyalkyl methacrylate, adsorbent carbonaceous material, adsorbent graphitic material, carbon fiber material, nano-material, adsorbent metal salts, alkaline earth metal metallic particles, ion exchange resin, linear polymers of glucose, and polyacrylamide.

### Claim 18 (depends on 1)

The method of claim 1, further comprising removing the photo-catalyst from the fluid after the contacting and the exposing.

### Claim 19 (depends on 1)

The method of claim 1, wherein the photo-catalyst further comprises at least one co-catalyst selected from the group consisting of CuO, MoO3, Mn2O3, Y2O3, Gd2O3, TiO2, SrTiO3, KTaO3, SiC, KNbO3, SiO2, SnO2, Al2O3, ZrO2, Fe2O3, Fe3O4, NiO, Nb2O5, In2O5, Ta2O5, CeO, and CeO2.

### Claim 20 (depends on 19)

The method of claim 19, wherein the co-catalyst is CeO2, and wherein the molar ratio of tungsten trioxide:CeO2 in the photo-catalyst lies in the range of 1:5 to 5:1.