Photocatalytic Decontamination of Airborne T2 Bacteriophage Viruses in a Small-Size TiO.sub.2/[beta]-SiC Alveolar Foam LED Reactor

Light emitting diodes (LEDs) emitting at 392 nm were successfully used as an irradiation light source and associated to TiO.sub.2/[beta]-SiC solid alveolar foams for designing a small-size, flow-through structured photocatalytic device for purifying air from airborne T2 bacteriophage viruses. Light emitting diodes are characterized by a high electricity-to-light yield, strength, a long lifetime, to ability to use a direct current power source, an almost-complete recycling rate, and a lack of mercury. Irrespective of the number of LEDs, we showed that the decontamination efficiency associated with removing airborne T2 bacteriophage viruses resulted from both the photocatalytic activity and the passive filtration effect of the TiO.sub.2/[beta]-SiC solid alveolar foams. A high photocatalytic filtration efficiency was observed with 56 LEDs and a logarithmic abatement of 3 was achieved for 60 min of run time, with an apparent time constant of 11.0 min after correcting for the natural decay of the bioaerosol. The pure filtration effect corresponded to a logarithmic abatement of 1, with an apparent time constant of 43.1 min. The interest in using 56 LEDs vs. 40 LEDs was highlighted in terms of the logarithmic abatement as well as energy effectiveness.