A New Photo‐catalyst Based Air Treatment System to Reduce the Risks from Transmission of Viruses and Bacteria

Treating the air in common, high traffic areas to eliminate biological contaminants (e.g., virus, bacteria, fungus) could reduce the transmission of airborne diseases. UV germicidal irradiation has been shown to inactivate all types of microorganisms including drug‐sensitive and multi‐drug‐resistant bacteria and different viral strains. TDA Research, in collaboration with Arizona State University (ASU), proposes to develop a high performance air treatment system that destroys the biological contaminants via a photo‐catalytic process. The system will use ASU’s approach, which has been proven successful in photo‐oxidation of organic molecules in water, for the treatment of the biological matter in air. In our system, the photocatalyst will be coated onto optical fibers which will be bundles up and attached to low cost, low energy UV LEDs. Careful design of the external catalyst coating will allow the light to be transported through total internal reflection inside these optical fibers without any major loss, while enabling sufficient penetration of light into the thin catalyst layer from inside so that it can activate the catalytic sites for photo‐oxidation on the surface of the fibers. The UV light will interact with the photocatalyst to generate reactive oxygen species (ROS) including hydroxyl radicals (•OH) and superoxide anions (O2‐•) which inactivate virus and bacteria. Our UV photocatalystsystem will efficiently reduce the risks of virus or bacteria exposure in high risk enclosed or semi‐enclosed environments, including concert halls, gyms, classrooms, bars, etc. In Phase I, we will carry out proof‐of‐concept evaluations at the bench‐scale using a limited set of bacteria to assess the feasibility. Using the results, we will design the air treatment system and estimate the installed cost and operating cost of the new photocatalytic filter.