酸化チタン含有ミストを用いたVOCガス分解処理プロセスの開発

概要

論文の詳細を見る
The present work studied the photocatalytic degradation of VOC gas by a mist formed by ultrasonic nebulization of TiO2 suspension with various wave lengths of UV rays. With UV365 irradiation, toluene was decomposed by photocatalytic reaction either on the mist surface or inside it. The toluene removal efficiency increased with the TiO2 concentration of the suspension. Water-soluble intermediates formed by the decomposition of VOC gases were completely trapped in the mist and were not detected at the reactor exit. Under UV254+185 irradiation, the complete decomposition efficiency to CO2 and H2O was higher than that with UV365 or UV254 irradiation. With UV254+185 irradiation, it was found that VOC gases were immediately degraded and converted to water-soluble intermediates by not only direct photolysis but also oxidation by OH radicals, because the removal rate of several organic gases depended on the reaction rate with OH radicals. On the other hand, ozone mainly contributed to complete decomposition of intermediates, because the complete decomposition efficiency of intermediates was decreased without ozone generation under UV254+185 irradiation in N2. Finally, we proposed the degradation mechanisms of organic gaseous pollutants on the mist surface.