Degradation of VOC gases in liquid phase by photocatalysis at the bubble interface
Degradation of VOC gases in liquid phase by photocatalysis at the bubble interface
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DOI：
10.1016/j.apcatb.2010.03.039
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发表时间：
2010-06
影响因子：
22.1
通讯作者：
K. Sekiguchi;Wakana Morinaga;K. Sakamoto;H. Tamura;Fumio Yasui;M. Mehrjouei;S. Müller;D. Möller
中科院分区：
文献类型：
--
作者：
K. Sekiguchi;Wakana Morinaga;K. Sakamoto;H. Tamura;Fumio Yasui;M. Mehrjouei;S. Müller;D. Möller
气相中的光催化反应具有许多缺点，包括相对湿度的不利影响、在反应器出口处分解中间体的排放以及分解中间体使光催化剂表面失活。在这项研究中，这些缺点可以克服使用一种新的光催化反应系统。挥发性有机化合物（VOC）气体在气泡界面处在TiO 2悬浮液中分解，通过使用TiO 2悬浮液在非均相液体气泡（LB）相中，因为中间体溶解到水中，然后不管湿度如何连续分解。选择甲苯、对二甲苯、苯乙烯和甲醛作为模型VOC气体，研究LB相中的光催化反应性。在LB相中的VOC气体的去除率是等于或大于在气相中，虽然在LB相的反应性取决于OH自由基的反应速率和VOC气体的疏水性。LB相中的反应也依赖于紫外光的波长和强度。具体而言，通过使用较短波长的UV照射来改善去除率和矿化率。最后，作为一个尝试性的实验，我们将微气泡技术应用到这个系统中。当VOC气体作为微气泡引入到系统中时，VOC气体被有效地去除，并且无论紫外光的波长和强度如何，都获得了高的去除率。
Photocatalytic reactions in the gas phase have a number of disadvantages including the adverse effects of relative humidity, the emission of decomposition intermediates at the reactor exit and the deactivation of the photocatalyst surface by decomposition intermediates. In this study, these disadvantages can be overcome using a novel photocatalytic reaction system. Volatile organic compound (VOC) gases were decomposed at the bubble interface in a TiO2suspension by using TiO2photocatalysis in the heterogeneous liquid-bubble (LB) phase since the intermediates dissolve into water and then are continuously decomposed regardless of humidity. Toluene, p-xylene, styrene and formaldehyde were chosen as model VOC gases to investigate photocatalytic reactivity in the LB phase. The removal ratio of VOC gases in the LB phase was equal to or greater than that in the gas phase, although the reactivity in the LB phase depended on the reaction rate of OH radicals and the hydrophobicity of the VOC gases. The reaction in the LB phase also depended on the wavelength and intensity of UV light. Specifically, the removal and mineralization ratios were improved by using shorter wavelengths of UV irradiation. Finally, as a trial experiment, we applied the microbubble technique to this system. When VOC gases were introduced into the system as microbubbles, VOC gas was effectively removed and high removal ratios were obtained regardless of the wavelength and intensity UV light.