Wang Wen-Yu, Ku Young
Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Road, Section 4, Taipei, Taiwan, ROC.
Water Res. 2006 Jul;40(12):2249-58. doi: 10.1016/j.watres.2006.04.041.
Photocatalytic processes using TiO(2) as a catalyst have attracted extensive attention for decomposition of organic contaminants. The determination of optimum reactor design and operational conditions are the major concerns for the development and potential application of the photocatalytic process. Various photoreactor types, photocatalyst arrangements, light sources, and operation conditions were reported. This study was focused on the application of the ultraviolet light emitting diode (UV-LED) as the UV light source for the photocatalytic decomposition of Reactive Red 22 (RR 22). The temporal behavior of the photocatalytic decomposition of RR 22 in aqueous solution by the UV-LED/TiO(2) with a rectangular planar fixed-film reactor operated in a recirculation mode was studied under various conditions including initial dye concentration, periodic illumination, light intensity, and arrangements of TiO(2) coating. The decomposition of RR 22 in aqueous solution by TiO(2) photocatalytic processes with the UV-LED was found to be technically feasible with a high TiO(2) coated weight (1.135g) and low pH value (pH 2). A Langmuir-Hinshelwood-type kinetic equation was adequate for modeling the photocatalytic decomposition of RR 22 by the UV-LED/TiO(2) photocatalytic processes. The experimental results indicated that the photonic efficiency with periodic illumination was much higher than those with continuous illumination. The photonic efficiencies with the quartz-liquid-catalyst (QLC) arrangement were higher than those with the quartz-catalyst-liquid (QCL) arrangement for experiments conducted at lower applied light intensity; however, the photonic efficiencies for these two arrangements were nearly identical for experiments conducted at higher light intensities.
使用二氧化钛（TiO₂）作为催化剂的光催化过程，在有机污染物分解方面已引起广泛关注。确定最佳反应器设计和操作条件是光催化过程开发和潜在应用的主要关注点。已报道了各种光反应器类型、光催化剂布置、光源和操作条件。本研究聚焦于应用紫外发光二极管（UV-LED）作为紫外光源，用于光催化分解活性红22（RR 22）。在包括初始染料浓度、周期性光照、光强度和TiO₂涂层布置等各种条件下，研究了采用矩形平面固定膜反应器以循环模式运行的UV-LED/TiO₂对RR 22在水溶液中的光催化分解的时间行为。发现采用UV-LED的TiO₂光催化过程分解水溶液中的RR 22在高TiO₂涂覆量（1.135g）和低pH值（pH 2）下在技术上是可行的。一个朗缪尔 - 欣谢尔伍德型动力学方程适用于对UV-LED/TiO₂光催化过程中RR 22的光催化分解进行建模。实验结果表明，周期性光照的光子效率远高于连续光照的光子效率。在较低施加光强度下进行的实验中，石英 - 液体 - 催化剂（QLC）布置的光子效率高于石英 - 催化剂 - 液体（QCL）布置；然而，在较高光强度下进行的实验中，这两种布置的光子效率几乎相同。
