ABSTRACT
Carbonaceous constituents in fine particulate matter (PM2.5) are often associated with adverse health effects in humans. Although air filtration technology is widely used for preventing exposure to PM2.5, the trapped PM2.5 still has hazardous property if not treated subsequently. Thus, this study aimed to realise detoxification of PM2.5 with a photocatalytic decomposition of carbonaceous compounds in PM2.5 samples collected on a quartz fibre filter coated with titanium dioxide (TiO2). The mass of PM2.5 gradually decreased with time during the UV irradiation with a significant release of carbon dioxide (CO2) as a product. The analysis of organic carbon (OC) and elemental carbon (EC) using a thermal/optical carbon analyser following the IMPROVE protocol showed that carbonaceous constituents such as OC1, OC2, OC3, OC4, and EC1 fractions were successfully decomposed by UV-irradiated TiO2, whereas EC2 and EC4 fractions were inert to the photocatalysis. However, a majority of the carbon content, approximately 92% of the total carbon, was reduced by the proposed method. This shows that the photon-induced TiO2 potentially reduces the hazardous effects of PM2.5.
