Le-Clech Pierre, Lee Eun-Kyung, Chen Vicki
UNESCO Centre for Membrane Science and Technology, School of Chemical Engineering and Industrial Chemistry, University of New South Wales, Sydney 2052, Australia.
Water Res. 2006 Jan;40(2):323-30. doi: 10.1016/j.watres.2005.11.011. Epub 2005 Dec 27.
Since the mid-1990s, numerous studies on the treatment of drinking water by photocatalysis have been reported. Once optimised, the photocatalytic process can completely degrade numerous natural and artificial organic compounds. In this study, a hybrid photocatalysis/membrane process was used as a polishing treatment of surface water containing a small concentration of natural organic matters (i.e. total organic carbon (TOC) concentration of around 3mg/L) which may be difficult to remove using conventional filtration or coagulation. An optimum pH of 4.5 and a TiO(2) concentration of 0.1g/L were found to lead to the highest removal efficiencies. The relative effect of the individual processes featuring in the hybrid system (UV radiation, TiO(2) adsorption and membrane filtration) was also assessed for different pH values. The membrane separation process was accounted to remove around 18% of the initial TOC concentration, while TiO(2) adsorption alone was generally responsible for less than 5% of TOC removal during the 120 min of the experiments. However, when the natural water was only radiated by UV light, up to 70% of TOC was removed. A synergetic effect was observed when the three processes (TiO(2), UV and membrane) were used together. Comparison of removal efficiencies obtained during real and model (International Humic Substance Society) waters treatment by photocatalysis is also presented, revealing the importance of the nature of the feed in this type of treatment.
自20世纪90年代中期以来，已有大量关于光催化处理饮用水的研究报道。一旦优化，光催化过程可以完全降解多种天然和人工有机化合物。在本研究中，光催化/膜混合工艺被用作对含有低浓度天然有机物（即总有机碳（TOC）浓度约为3mg/L）的地表水的深度处理，这类地表水采用传统过滤或混凝可能难以去除。研究发现，最佳pH值为4.5，TiO₂浓度为0.1g/L时去除效率最高。还评估了混合系统中各个过程（紫外线辐射、TiO₂吸附和膜过滤）在不同pH值下的相对作用。膜分离过程去除了约18%的初始TOC浓度，而在120分钟的实验过程中，仅TiO₂吸附对TOC去除的贡献通常不到5%。然而，当天然水仅受到紫外线照射时，TOC去除率高达70%。当三种工艺（TiO₂、紫外线和膜）一起使用时，观察到了协同效应。本文还比较了光催化处理实际水和模型水（国际腐殖质协会）时获得的去除效率，揭示了进水性质在这类处理中的重要性。
