Study On Treatment Of Wastewater By Nanometer Photocatalyst

Environmental pollution has become a serious and global problem with the development of industry. Photocatalytic redox reactions used in degrading pollution organics have gained wade interest because of their simplicities, economic advantages and without the second pollution. The light source often used in AOP is UV light but researchers are interested in the solar or visible light in recent years owing to UV light is expensive and difficult to achieve. To improve the catalytic of material, many research groups have focused their attention on the preparation of the nanometer photocatalyst and improve the activity of photocatalyst. In this work, the solar light catalytic degradation of methylene blue solution and dye industrial wastewater by nanometer-size Cu2O was studied. The results indicated that the methylene blue was degraded efficiently.It has been widely reported that application of the anodic bias can restrain the reposition of photogenerated electron and hole. Thus, to improve the photocatalytic efficiency of the TiO2 particles, we transplant the SPE (Solid Polymer electrolyte) in the electroassisted photocatalysis at first time and found that this technique can be used in the condition of without addition of supported electrolyte and can keep the anode from useless reaction with HI produced on the cathode.In this thesis, three methods were studied on improving the efficiency of photodegradation.1, Photodegradation of wastewater with nano-CuaO powder using the solar light. Nanometer-size Cuprous Oxide, a new material recently developed by our laboratory, was applied to the treatment of methylene blue and dye printing wastewater under the irradiation of solar light.2, The preparation of nano-TiO2 thin film doped with RuO2, which is used as an anode for electroassisted photocatalysis, has been investigated. The TiO2 thin film electrode was prepared by sol-gel method and the sol-gel processwas studied under different conditions. The degradation experiments of methylene blue show that this anode is effective enough and the applied amount of Ru can be reduced from 30% to 1%, compared with the anode material recommended in the related literatures. With the TiOa thin film anode, a new electrochemically assisted photocatalytic system was built. 3, Electro-assisted photodegradation of methylene blue was studied in the SPE system. The aim of this dissertation was to investigate the effects of SPE technique on electrochemically assisted photocatalytic system. The result indicted that the SPE technique can improve the photocatalytic efficiency. The process was characterized by its simplicity, better efficiency and without the second pollution system.