Purified hydrogen peroxide gas microbial control methods and devices
The present invention relates to methods and devices for providing microbial control and/or disinfection/remediation of an environment. The methods generally comprise: generating a Purified Hydrogen Peroxide Gas (PHPG) that is substantially free of, e.g., hydration, ozone, plasma species, and/or organic species; and directing the gas comprising primarily PHPG into the environment such that the PHPG acts to provide microbial control and/or disinfection/remediation in the environment, preferably both on surfaces and in the air.
1. A diffuser apparatus for producing hydrogen peroxide gas from humid ambient air, said diffuser apparatus comprising:
(a) an outer diffuser shell comprising a plurality of pores or vents;
(b) an air distribution mechanism configured to provide a flow of said humid ambient air into and/or through at least a portion of said outer diffuser shell;
(c) an air permeable structure disposed within said outer diffuser shell, wherein said air permeable structure comprises at least one active surface at least partially coated with a metal or metal oxide catalyst; and
(d) an ultraviolet light source configured to irradiate at least a portion of said at least one active surface of said air-permeable structure as the humid ambient air contacts at least a portion of said catalyst on said at least one active surface of said air-permeable structure,
wherein said air distribution mechanism is configured to direct said humid ambient air through said air permeable structure in a direction perpendicular to said at least one active surface of said air permeable structure,
wherein said humid ambient air has a residence time on said at least one active surface of said air-permeable substrate structure of less than a second, and
wherein said outer diffuser shell is lined on an interior surface thereof with said air permeable structure such that said hydrogen peroxide gas formed on said at least one active surface of said air permeable structure is directed out of said diffuser apparatus via said pores or vents of said outer diffuser shell and into a surrounding environment when said diffuser apparatus is in operation.
2. The diffuser apparatus of claim 1 , wherein said air distribution mechanism is a fan.
3. The diffuser apparatus of claim 1 , wherein said ultraviolet light source produces ultraviolet light at least one range of wavelength in the range of between about 182 nm and about 254 nm, between about 187 nm and 250 nm, or between about 188 nm and about 249 nm.
4. The diffuser apparatus of claim 1 , wherein said ultraviolet light source produces ultraviolet light having more than one range of wavelengths.
5. The diffuser apparatus of claim 1 , wherein said metal or metal oxide catalyst is selected from titanium dioxide, copper, copper oxide, zinc, zinc oxide, iron, iron oxide, or mixtures thereof.
6. The diffuser apparatus of claim 1 , wherein said source of ultraviolet light comprises an ultraviolet light emitting lamp.
7. The diffuser apparatus of claim 1 , wherein said ultraviolet light source is an array of ultraviolet light emitting diodes (UV LEDs).
8. The diffuser apparatus of claim 1 , wherein said hydrogen peroxide gas directed out of said diffuser apparatus comprises hydrogen peroxide in an amount of about 0.005 ppm to about 0.10 ppm.
9. The diffuser apparatus of claim 1 , wherein said ultraviolet light source is tubular in shape.
10. The diffuser apparatus of claim 9 , wherein said outer shell of said diffuser apparatus comprises an elongated wedge-shaped or tube-shaped diffuser shell.
11. The diffuser apparatus of claim 1 , wherein the hydrogen peroxide gas directed out of said diffuser apparatus comprises hydrogen peroxide in an amount of not more than about 0.10 ppm.
12. The diffuser apparatus of claim 11 , wherein the hydrogen peroxide gas directed out of said diffuser apparatus comprises hydrogen peroxide in an amount of at least 0.005 ppm.