Preparation And Characteristics Of TiO₂Nanotube Catalysts Used In The Microfiltration Membrane Separation

The application of titania dioxide (TiO2) is considered as a green technology for water treatment and air purification because of its high chemcial stability, nontoxicity, safety and low cost toward both human and environment. However, separation and recovery of TiO2photocatalyst are significant obstacles for application. Therefore, development of an efficient process that had high photocatalysis and separation seems to be the most appropriate strategy.In this paper, TiO2nanotube was prepared by hydrothermal method with P25powder, and the effect of hydrothermal time, temperature and annealed temperature on its properities was investigated. Then the photocatalytic activities were evaluated by photodegradation of reactive brilliant blue X-BR under UV light compared to P25, also the influence of different pH on the photocatalysis of TiO2nanotube and P25was discussed. N6and CN-CA microfiltration membranes with pore size3μm and5μm were selected to separate TiO2photocatalyst from solution. The membrane flux and rejection during the separation of P25and TiO2nanotube were investigated in detail. Results showed that at110℃hydrothermal treatment for24h, and then heated at300to600℃, the obtained TNT showed the higher photocatalytic activity than P25in reactive brilliant blue X-BR degradation, especially at400℃, the photocatalytic activity of TNT was2.5times higher than that of P25. and the reaction obeyed L-H first order reaction kinetic model. Acid and strong alkaline conditions were beneficial to photodegradation of X-BR.In membrane separation process, the rejection of TNT was above99%, and the membrane flux in TNT separation was4-5times higher than P25no matter what membrane was used, implying the less membrane fouling, especially in neutral pH of solution, the membrane flux reached the highest.