ABSTRACT
The degradations of trace hexane under high flow rate (5 L/min-17 L/min) in the gas phase by TiO2/UV, O3/UV and O3/TiO2/UV were studied. The kinetic effects of the inlet concentration of hexane, flow rate, water concentration and ozone dosage on the conversion of hexane in the three processes were examined respectively. The experimental results showed that the addition of ozone to the photocatalysis process increased the conversion of hexane significantly. The O3/TiO2/UV process was more efficient than the TiO2/UV in decomposing hexane. The degradation rate increased with increasing the initial concentration of hexane in the processes of TiO2/UV and O3/TiO2/UV. They matched well with the Langmuir-Hinshelwood (L-H) kinetic model. In the range of flow rate studied, the degradation rate increased with an increasing flow rate in both processes of TiO2/UV and O3/TiO2/UV, while was not affected in the process of O3/UV. The degradation rate in the three processes was affected by water concentration. The degradation rate of the two processes O3/UV and O3/TiO2/UV increased almost linearly with the increase of ozone dosage.
