Photodecontamination of surfaces

Claim 1

A method of destroying a chemical warfare agent, pesticide or other hazardous organic chemical contaminant on a surface to be decontaminated comprising the steps of positioning a pulsed light flashlamp system in proximity to the surface to be decontaminated, said pulsed light flashlamp system providing high intensity light pulses over a wide surface area having a light radiation spectrum having a broad-band frequency distribution such that at least about 50 percent of the light energy thereof is distributed in the visible spectrum between 380 and 720 nanometers of wavelength and having a duration of less than about 10 milliseconds, intimately contacting said contaminant with a high optical density visible spectrum light-absorption agent that absorbs broad-band frequency light radiation in an amount sufficient to provide a neutral density of about 0.3 or greater relative to said light radiation spectrum, said agent being distributed over said surface at a level of about 5 Kg per hectare or less, and exposing said surface to be decontaminated to at least one pulse of high intensity broad-band incoherent light from said flashlamp system at an intensity of at least about 6 joules per square centimeter at said surface to be contaminated such that said agent absorbs at least 50 percent of the energy of said at least one broad-band light pulse for said light-absorption agent to generate sufficient heat at a temperature of at least about 1000° C. to vaporize and decompose said hazardous organic chemical contaminant from the surface without substantially redispersing said contaminant, whereby said surface is at least partially shielded from said at least one light pulse by said absorption such that deterioration of said surface is avoided or minimized.

Claim 2

A method of destroying a chemical warfare agent, pesticide or other hazardous organic chemical contaminant on a surface to be decontaminated comprising the steps of positioning a pulsed light flashlamp system in proximity to the surface to be decontaminated, said pulsed light flashlamp system providing high intensity light pulses over a wide surface area having a light radiation spectrum having a broad-band frequency distribution such that at least about 50 percent of the light energy thereof is distributed in the visible spectrum between 380 and 720 nanometers of wavelength and having a duration of less than about 10 milliseconds, intimately contacting said contaminant with a high optical density visible spectrum light-absorption agent that absorbs broad-band frequency light radiation in an amount sufficient to provide a neutral density of about 0.3 or greater relative to said light radiation spectrum, said agent being distributed over said surface at a level of about 5 Kg per hectare or less, and exposing said surface to be decontaminated to at least one pulse of high intensity broad-band incoherent light from said flashlamp system at an intensity of at least about 6 joules per square centimeter at said surface to be contaminated such that said agent absorbs at least 50 percent of the energy of said at least one broad-band light pulse for said light-absorption agent to generate sufficient heat at a temperature of at least about 1000° C. to vaporize and decompose said hazardous organic chemical contaminant from the surface without substantially redispersing said contaminant, whereby said surface is at least partially shielded from said at least one light pulse by said absorption such that deterioration of said surface is avoided or minimized.