Kinetic study for photocatalytic degradation of volatile organic compounds in air using thin film TiO_2 photocatalyst

摘要

The presentpaper examined the kientics of photocatalytic degradation of volatileorganic concentration of VOCs,water vapor content and photon flux of ultra-viloet (UV)light.A batch photo-reactor was specifically designed for this work.The photocatalytic degradation rate increased with increasing the initial concentration of VOCs,but maintained almost constant beyond a certain concentration.It matched well with the Langmuir-Hinshelwood(L-H) kinetic model.For the influence of water vapor in a gas phase photocatalytic degradation rate,there was an optimum concentration of water vapor in the degradation of TCE and methanol.And,wate rvapor enhanced the photocatalytic degradation rate of toluene,where as it inhibited that of acetone.As for the effect of photon lfux,it was found that photocatalytic degradation occurs in two regimes with respec to photon flux.