Department of Chemical and Environmental Technology, ESCET, Universidad Rey Juan Carlos, Móstoles Madrid, Spain.
Water Sci Technol. 2010;61(2):507-12. doi: 10.2166/wst.2010.876.
The photocatalytic disinfection efficiency has been investigated for two immobilized TiO(2) catalytic systems (wall reactor and fixed-bed reactor) in a solar pilot plant. Their performances have been compared with the use of a slurry reactor and the solar disinfection without catalyst. The use of photocatalytic TiO(2) wall reactors does no show clear benefits over the solar disinfection process in the absence of catalyst. The reason is that the efficiency of the solar disinfection is so high that the presence of titania in the reactor wall reduces the global efficiency due to the competition for the absorption of photons. As expected, the maximum efficiency was shown by the slurry TiO(2) reactor, due to the optimum contact between bacteria and catalyst. However, it is noticeable that the use of the fixed-bed reactor leads to inactivation rate quite close to that of the slurry, requiring comparable accumulated solar energy of about 6 kJ L(-1) to achieve a 6-log decrease in the concentration of viable bacteria and allowing a total disinfection of the water (below the detection limit of 1 CFU mL(-1)). Not only the high titania surface area of this configuration is responsible for the bacteria inactivation but the important contribution of the mechanical stress has to be considered. The main advantage of the fixed-bed TiO(2) catalyst is the outstanding stability, without deactivation effects after ten reaction cycles, being readily applicable for continuous water treatment systems.
已在太阳能中试工厂中对两种固定化 TiO(2) 催化体系（壁式反应器和固定床反应器）的光催化消毒效率进行了研究。将它们的性能与使用淤浆反应器和无催化剂的太阳能消毒进行了比较。使用光催化 TiO(2) 壁式反应器并没有比没有催化剂的太阳能消毒过程表现出明显的优势。原因是太阳能消毒的效率非常高，以至于反应器壁中的 TiO(2) 的存在由于对光子的竞争而降低了整体效率。不出所料，由于细菌和催化剂之间的最佳接触，TiO(2) 淤浆反应器表现出了最高的效率。然而，值得注意的是，使用固定床反应器可导致与淤浆相当接近的失活动率，需要可比的累计太阳能约 6 kJ L(-1)，以实现对存活细菌浓度的 6 个对数减少，并允许对水进行完全消毒（低于检测限 1 CFU mL(-1)）。不仅这种配置的 TiO(2) 具有高的比表面积负责细菌失活，而且还必须考虑机械应力的重要贡献。固定床 TiO(2) 催化剂的主要优点是其出色的稳定性，在十个反应循环后没有失活效应，可轻松应用于连续水处理系统。
