Saturation Concentration of Gas Pollutants in Photocatalysis

Saturation behavior in photocatalysis is investigated for volatile organic carbons (VOCs) and ammonia by using a tubular photoreactor and TiO2nanoparticles, synthesized by a flame chemical vapor deposition (CVD) process. Degradation degree versus initial concentration shows that saturation behavior occurs at different initial concentrations for different gas pollutants. The saturation concentration is obtained by taking as the intersection of the level off part and the tangential line to the rapid change part from the curve of degradation degree versus initial concentration. The saturation concentration for benzene is as low as 0.063 mg/m3, and is up to 720mg/m3for formaldehyde for TiO2nanoparticles synthesized by a flame CVD process.