The end product of this research will be a fully tested prototype of a portable air cleaner that targets airborne microorganisms that convey infectious disease, e.g. tubercle bacilli. This air cleaner will remove airborne particles that exceed 1 mum in size and collect them on a surface where they can be irradiated with a built-in germicidal ultraviolet radiation lamp. The air cleaner utilizes a micro-trap impaction technique, demonstrated to be effective in Phase I, to collect particles. In Phase II, the design will be optimized through numeric and scaled-up to a flow rate of 5 m3/min to process enough air for a typical room. After initial small-scale tests, single-pass penetration tests at 2.5 m3/min will be conducted with inert aerosols and microorganisms, including bacteria, mold spores and bacteria phage. Single-pass tests will include controlled UV exposures of collected microorganisms to evaluate the efficacy of UV sterilization. Testing the viability of collected microorganisms without UV exposure will determine if the micro- trap would be suitable as an alternative bioaerosol sampling technology. Full-scale testing of a prototype at 5 m3/min, with integrated UV lamp and air mover, will be performed in a room- sized chamber according to standard air-cleaner test protocols to measure a clean air delivery rate.
The air cleaner unit to be built will be small and portable such that it could be used in public settings where permanent UVGI or filtration systems are impractical. Example applications include homeless shelters or drug treatment centers where transmission of TB is of concern.
