Study Of TiO₂ Photocatalyst Supported On A Magnetically Separated Carrier And Its Reactor

In nowadays, nanosized TiO₂ has been becoming to a kind of photocatalyst with the biggest application potentiality especially in the treatment of wastewater containing poisonous organic compounds which are difficult to destroy, because of its characterisitics of high catalytic activity, and resistance of the corrosion from acid solution, alkaline solution, and photochemistry.Aiming at improving the photocatalytic activity and solving the problem of effectly fixing, separating and recycling, modified TiO₂ photocatalyst immobilized on NiCuZn ferrite was prepared. Meanwhile, we investigated and made one kind of photocatalytic reactor which can easily separate the photocatalyst.This work has practical meaning for the application of photocatalysis degradation technology.In this thesis, we use the tbutyl titanate and titanium trichloride as main materials, combine the methods of auto-combustion,sol-gel,powder-gel and coprecipitation to make modified TiO₂ photocatalyst immobilized on NiCuZn ferrite, and measure it by XRD, SEM and BET techniques; use ultraviolet germicidal lamp with main wavelength of 253.7nm as light source, and take azobyestuff methyl-orange solution as treatment object, the catalyst is evaluated by using to degrade the methyl-orange solution. The results show that the modified composite photocatalyst, which uses magnetic carrier as basic material taking Ni-Zn ferrite as main spinelle crystal, silicon sol acts as the first transition layer, low concentration TiO₂ layer made by TiCl₃ as following isolation layer; while taking the method of power-gel to improve the surface layer, has superior magnetism and its degradation property can get up to 90%.Meanwhile, the process of degrading the organic pollutant by photocatalyst based on TiO₂ evolves from laboratory to application. In this paper, we designe and make an intermittent and batching photocatalytic reactor combining the merits of the suspending and loading photocatalytic reactor. The characteristic of this photocatalytic reactor is that the nanosized TiO₂ powder is suspending in tne reactor while in process of treating poisonous organic compounds, after the treatment, it can separate the nanosized TiO₂ powder from the solution effectively by the strong magnetic fields, so there're no longer problems of filtration, centrifuge, coagulation and flocculation. An intermittent and batch water-treatment process has been developed with the high photocatalytic efficiency.