AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
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Characterization of a Flow Type Vacuum Ultraviolet Photocatalysis Reactor for Airborne Microorganisms and VOCs
JEONGHYUN KIM, Jaesung Jang, Ulsan National Institute of Science and Technology, Korea
Abstract Number: 70 Working Group: Indoor Aerosols
Abstract Indoor air pollutants that can cause a risk for human health can be classified into biological, physical and gaseous pollutants. Biological pollutants include airborne viruses, bacteria and fungi. Volatile organic compounds (VOCs) are typical gaseous pollutants causing health problem such as sick building syndromes (SBS). Up to now, most of conventional air purification techniques have been focused on the degradation of single pollutant but not on multiple air pollutants. On the other hand, vacuum ultraviolet (VUV) photocatalysis has recently been considered as one of the promising techniques for the degradation of multiple air pollutants because of its high-energy photon, although residual ozone is generated by dissociation of oxygen. In this study, to characterize the performance of a flow type VUV photocatalysis reactor, where the residence time was less than 0.01 sec, for biological and gaseous pollutants, MS2 bacteriophage, Pseudomonas fluorescens (gram-negative), Bacillus subtilis spore (gram-positive) and toluene were used as the target pollutants. In addition, it is generally known that the influence factors of VUV photocatalysis involve the light wavelength (185 nm and 254 nm), ozone and reactive oxidant species. In order to clarify which component is more responsible for the degradation of the air pollutants, VUV photocatalysis was compared with five processes: VUV photolysis (without photocatalyst), UV photolysis, ozone dose combined with UV photolysis, ozone dose treatment alone and VUV combined with UV photocatalysis. We eventually developed the effective flow type VUV phtocatalysis reactor that not only can degrade both biological and gaseous air pollutants but also can reduce residual ozone generation (35 ppb), i.e., less than the Occupational Safety and Health Administration (OSHA) permissible level. Therefore, we think the VUV-based air purification technique has the potential for the simultaneous degradation of multiple air pollutants at large flow rates.