Research On Photocatalytic Degradation Of Municipal Sewage By Doping-modified TiO₂/Cenospheres

TiO2has been widely used as an ideal photocatalyst, because of its chemical stability, high photocatalytic activity, low cost and nontocicity. The band gap of T102however is wide (3.2eV), it can only be excited by UV light (λ<387nm). Its utilization capacity for solar energy is very low and its quantum efficiency low either.In this paper, with TiCl4as the raw material, cenospheress of Huainan power plant as the carrier, the loaded La3+(or Fe3+) doped TiO2photocatalysts were prepared. The content of the various elements in the supported catalyst was determined by EDS. The spectralabsorption of catalyst was characterized by UV-Vis.Moreover.The influence of kinds of doping ions(La3+,Fe3+), ion doping concentration, initialvalue of COD, pH value, the density of catalyst and H2O2, the deposit times of TiO2, and the time of catalyst regeneration on photocatalytic degradation of wastewater were investigated.The results show that the effect of the dopant content of La3+or Fe3+over on waste-water degradation rate is great. In a certain range, with the increase of concentration of H2O2, the degradation of wastewater is increasing, the degradation rate greatly influenc-ed by the initial concentration in the wastewater, the lower initial concentration, the higher the degradation rate. Under the condition of acid solution, the degradation rate is more higher; With the increasing of the lighting time, the degradation rate of the waste-water is also increasing and achieving balance at last. Moreover, with the increased of regeneration frequencies, the activity of photocatalyst continuously decreased, degrada-tion rate of wastewater is reduced. The degradation rate reach up to70%when the best condition.This study shows that, La3+(or Fe3+) doped nano-TiO2catalyst oreoaration and modified set in one step by microemulsion solved the catalyst immobilization and recycling utilization. And the method is simple, equipment requirements low. Cenospheres as the carrier efficient use of power plant emissions waste, and inexpensive source of raw materials enhanced the usability of the catalyst.(La3+,Fe3+) co-doped TiO2spectral absorption range move to the visible light and photocatalytic degration ability. It has the advantages of moderate reaction condition, low energy consumption, easy and simple to handle, does not have two pollution etc, becoming a type of burgeoning green water treatment technology.