基于二氧化钛的光催化氧化：一种降解有机污染物的清洁工艺

Photocatalytic oxidization based on titanium dioxide： a cleaner process for degradation of organic pollutants

光催化氧化降解有机污染物是一种可行的处理废水和废气的方法。近年来，基于二氧化钛的分解和矿化有机污染物研究报道很多。主要论述了光催化氧化的基本原理，尤其说明了光催化氧化在处理有机污染物中的各种应用。同时，应用溶胶-凝胶方法和浸渍-提拉工艺在以赤泥为主要原料制备的多孔陶瓷滤球表面涂层二氧化钛薄膜，选择甲醛和丙酮的混合溶液作为目标分解物。实验结果显示：在500℃下热处理1h的涂膜滤球具有优越的光催化性能。甲醛和丙酮的降解率在光照50min后分别达32．45％和3．80％，而反应器中的二氧化碳和水的浓度增高，其中二氧化碳的浓度上升了12．28％，这表明一部分甲醛和丙酮已被矿化成二氧化碳和水。鉴于二氧化钛薄膜的光催化性能和多孔性能，为了进一步利用膜多孔陶瓷滤球的光催化和过滤性能，利用这种改性滤球处理含油废水和微污染水源水将在接下来的工作中研究。

The photocatalytic degradation of various organic compounds has been suggested as a viable process to treatment wasterwater and wastergas. In recent years, the decomposition and mineralization of organic contaminants based on TiO2 have been widely demonstrated, and the application and target compounds are numerous. The purpose of present study is to present the basic principles of the photocatalysis and especially to show the various applications of the photocatalysis in the treatment of organic pollutants. At the same time, the mixed solution of formaldehyde and acetone was used as a model compound to test the photocatalysis of TiO2 thin film fixed on porous ceramic filtration ball by dipping-withdrawing from the TiO2 sol. According to the experimental results, the porous ceramic filtration balls coated TiO2 thin film and heat-treated at 500℃ for lh have excellent photocatalytical activity and the decomposition rates of formaldehyde and acetone reached 32.45% and 3.80% respectively after 50 minutes illumination. On the contrary, the concentrations of CO2 （conc- entration rising up 12.28%）and H20 in the container increased, which suggests that some formaldehyde and acetone have been mineralized into CO2 and H2O. In view of photocatalytical and porous structure of TiO2 thin film, treatment of containing oil wasterwater and micropolluted source water will further be researched in the following work, in order to make full use of photocatalysis and filtrating performance of filtration ball coated TiO2.