Improving the efficiency of a bioaerosol disinfection reactor by using ultraviolet C light-emitting diodes and titanium dioxide photocatalyst.

This study used ultraviolet (UV)-C light-emitting diodes (LEDs) and titanium dioxide (TiO2) photocatalyst to design a high-efficiency bioaerosol disinfection reactor. It conducted experiments and simulations to investigate the effects of baffle angle (-10°, 0°, and 10°) on the airflow field, irradiance distribution, and photocatalytic efficiency of the designed reactor. When baffle surfaces were not coated with photocatalyst, a baffle angle of 0° effectively prolonged the microbial residence time, causing bacteria to receive the maximum UV fluence of 22.07 mJ/cm2, which led to the highest log inactivation value of 1.91. However, when the baffle surfaces were coated with TiO2 photocatalyst, a baffle angle of -10° resulted in the highest photocatalytic disinfection efficiency and log inactivation value. After the baffles were coated, the log inactivation value under a baffle angle of -10° increased from 1.67 to 2.40, representing an increase of approximately 44%. This improvement was attributable to the baffle angle of -10° substantially increasing the photocatalytic efficiency at the channel turns and the probability of bioaerosols coming into contact with the photocatalyst. Overall, the current findings can provide a reference for the design of bioaerosol disinfection reactors comprising UV-C LEDs and TiO2 photocatalyst.