【作者】 刘冬妮；

【导师】 郑铭；

【作者基本信息】 江苏大学 ， 环境工程， 2003， 硕士

【摘要】 TiO₂光催化氧化是近30年来发展起来的一种高级氧化技术。由于该项技术可以将许多其他方法难降解的有机污染物氧化分解为CO₂、H₂O等无毒、无害的小分子物质，因此日益成为广大环保工作者的研究热点。目前对该项技术的研究主要集中在反应机理、反应动力学、高活性催化剂的制备及高效大型光催化反应器的设计等方面。本论文旨在为TiO₂光催化反应体系机理方面的研究作一些基础性的工作，探讨了以下几个问题： 1．悬浮体系光催化的几个影响因素的探讨：以某种染料废水的COD为目标降解物，以30nm的TiO₂粉末为光催化剂，用正交实验设计法安排实验，考察了水样初始pH值、催化剂投加量及反应时间对悬浮体系光催化反应效率的影响，结果表明，对此种废水而言，反应时间的影响最大，催化剂投加量的影响次之，水样初始pH值的影响最小，且最佳的反应条件为水样初始pH值为7.0，催化剂投加量为3g／L，反应时间为3h，此时废水的COD降解率可达89.5％。 2．影响TiO₂薄膜光催化性能的几个因素的探讨：用溶胶-凝胶法在石英玻璃试管外壁成功的涂附了TiO₂薄膜，并以某种水样的COD为目标降解物，考察了薄膜的焙烧温度、反应时间、涂膜次数及水样初始pH值对固着体系光催化反应效率的影响，结果表明，薄膜焙烧温度为600℃，反应时间为5h，涂膜次数为5次，水样初始pH值为8.0时，此种水样的COD降解率达到最高值76.8％。 3．悬浮体系与固着体系光催化效率的比较：用环氧树脂及其助剂组成的粘合剂，将纳米TiO₂粘结在普通玻璃试管外壁，并分别考察了相同TiO₂用量、相同水样初始pH值及相同反应时间的条件下固着体系与悬浮体系的光催化反应效率，结果表明，纳米TiO₂固定态的光催化效率比悬浮态的降低了约25％。 此外，由以上实验内容引出的很多问题亦在论文的最后一章进行了说明及分析，并指出了今后的研究方向。更多还原

【Abstract】 Ti02 Photocatalytic Oxidization, one of the advanced oxidization processes(AOP), has developed in recent 30 years. Because it can oxidize and degrade many organic contaminants which are hard to be degraded by other methods into CO2, H2O and other small molecules, this technology is increasingly becoming one of the popular research subjects in the field of photochemistry and environment protection. Now, the research on this technology is focused on the reaction mechanism, reaction kinetics, preparation of TiO2 with high catalytic activity and devising of photocatalytic reactor with high efficiency and large scale, etc. In order to do some basic things for the research on the reaction mechanism of TiO2 photocatalytic system, following problems are studied in this paper:1. The study on several factors which influence TiO2 aqueous suspension: by using COD of certain dye wastewater as the objective decomposition substance and using nanometer TiO2 as the photocatalyst, the effects of initial pH, dosages of Ti02 and reaction time on the photocatalytic efficiency of aqueous suspension were investigated in detail. The experimental results show that reaction time has greatest effect on the photocatalytic efficiency of this system, dosages of TiO2 takes second place and initial pH has the least effect on that. Furthermore, the optimal reaction condition is that initial pH is equal to 7.0, dosages of TiO2 is 3g/L and reaction time is 3 hours, under which the COD degradation rate of this wastewater is 89.5%.2. The study on several factors which influence the photocatalytic activity of TiO2 thin film: the TiO2 thin films deposited on the ektexine of quartz glass tubes was successfully prepared by sol-gel processing. By using those TiO2 thin films as photocatalyst and using COD of certain wastewater as the objective decomposition substance, effects of calcination temperature of the films, reaction time, soaking times and initial pH on photocatalytic efficiency of the fixed TiO2 film system were investigated in detail. The results show that COD degradation rate can reach the maximum 76.8% when calcination temperature of the films is 600℃, reaction time is 5 hours, soaking times is 5 and initial pH is 8.0.3. The comparison of photocatalytic efficiency of TiO2 aqueous suspension with that offixed TiO2 system: by using epoxy resins system as the bond, the nanometer TiO2 thin films deposited on the ektexine of common glass tubes was successfully prepared. Moreover, the photocatalytic efficiency of aqueous suspension and fixed nanometer Ti02 film system were compared under such conditions as the dosages of TiO2, initial pH and reaction time were all same. The results show that compared with that of the former system, the photocatalytic efficiency of the latter system is approximately reduced by 25%.In addition, a lot of problems which have been caused by those experiments were illuminated and analyzed in the last chapter of this paper. Moreover, further research direction was pointed out.更多还原