Illumination conditions of photocatalyst-containing mist on the degradation of organic compounds

• The illumination conditions of photocatalyst-containing mist were studied. • UV light, ultrasound, and mist were applied to a mixture of TiO 2 and phenol. • Higher light intensities provided to the mist improved phenol degradation. • Excess TiO 2 prevented mist generation and utilization. • Findings inform the design of reactors that use photocatalysts and mist. Photocatalysis is a promising method for treating wastewater containing toxic organic pollutants. To improve the degradation of those pollutants, the utilization of mist that contains photocatalysts has been considered. In this study, the light illumination conditions of the mist that affect photocatalytic degradation were investigated to provide insight into the design of reactors that utilize photocatalyst-containing mist. In the reactor, UV light, ultrasound (US), and US-generated mist were applied to a mixture containing the TiO 2 photocatalyst and phenol as the model organic pollutant. The results indicated that higher UV intensities and TiO 2 dosages affected the illumination conditions to improve the degradation of phenol. However, at higher TiO 2 dosages, mist was not generated, so its enhanced illumination was not utilized in the degradation reactions. The analysis of the reaction kinetics suggested the enhancement of the illumination condition by the mist. These findings provide insight into the design of the reactor that utilizes photocatalyst-containing mist to improve the irradiation conditions and promote photocatalytic reactions.