The Preparation, Characterization And Performance Of TiO₂ Microsphere Photocatalysts Prepared By Ultrasound Assisted Hydrothermal Process And Their Application For The Photocatalytic Degradation Of Bisphenol A In Wastewater

Endocrine Disrupting Chemicals(EDCs), which is also called Environmental Hormone, is a kind of exogenous chemicals that can destroy normal metabolism,functions of exudation and procreation of organism and human being through disrupting the synthesis, exudation, and metabolism of nature hormone. As an important material of organic industry, Bisphenol A(BPA) exists widely in the environment, which is very harmful to organism and human being.? Titania heterogeneous photocatalysis oxidation technology has being used in the treatment of EDCs because of its safety, high reaction speed, complete oxidation, low energy consumption and no secondary contamination.For the existing TiO₂, is dufferent to recycled such as commercial P25, or has low photocatalytic efficience. From this point, used ultrasound-assisted hydrothermal method to prepare TiO₂ microspheres and absorption-heating prepared Gd-TiO₂ microspheres. Using phenol as a model organism compounds to evaluate the photocatalytic activity. Then the Optimum photocatalytic of TiO₂ microspheres and Gd-TiO₂ microspheres are characterized by adsorption capacity,the practical efficiency,XRD,BET,SEM,FT- IR. Finally, used TiO₂ microspheres as photocatalyst to research the degradation of bisphenol A(BPA) in a new gas-liquid-solid circulating slurry photocatalytic reactor(GLSCSPCR). And use the Response Surface Methodology (RSM) to. And ompared the material of TiO₂ microspheres and Gd-TiO₂ microspheres on degradation of BPA at the optimization process conditions.This paper studies'conclusions as following:1,The parameters of preparing TiO₂ microspheres , such as the concentration of water in ethanol, n (H₂O)/ n (Ti), n (Ti) / n (P123), ultrasonic time and calcination temperature were study, the optimized results as follows: the concentration of ethanol in water is about 10 % (V / V), n (H₂O) / n (Ti)≈5, n (Ti) / n (P123)≈46, ultrasonic dispersion time: 90 min, calcination temperature: 400℃; On this basis, using adsorption-heating method prepared Gd-TiO₂ microspheres, and the calcination temperature,raw material and n ( Gd) / n (Ti) were studied, the optimal preparation conditions: raw material is not calcined microspheres, n (Gd) / n (Ti) = 1.5 %, calcination temperature: 600℃.2,The practical efficiency of TiO₂ microspheres and Gd-TiO₂ microspheres were higher than the P25 3.5 and 6.5 times; the both have the same adsorption properties, multi-level structure of the interface and BET characterization 185 m²/g; The two crystal based mainly anatase, the rates were 73 % and 85 %; To the TiO₂ microspheres, Gd-TiO₂ microspheres has the FT-IR peak of the O-H bond and surface hydroxyl groups.3,The degradation of TiO₂ microspheres on Bisphenol A showed the single factor experiment were photocatalyst concentration 4 g/L, superficial gas velocity 8.34×10^-3 m/s and superficial liquid velocity 8.34×10^-3 m/s , the degradation rate of up to 94 %. Then optimized by response surface method, the degradation of model equations: y=94.44+5.70x₁-0.084x₂-0.18x₃-2.48x₁x₂+2.64x₁x₃-13.64x₁²-2.42x₂²-3.99x₃², further, the optimum of degradation conditions were: photocatalyst concentration 4 g/L, superficial gas velocity 7.83×10^-3 m/s and superficial liquid velocity 8.62×10^-3 m/s, the degradation rate of bisphenol A 95.1 %. Under the optimized operation conditions, the Gd-TiO₂ microsphere of bisphenol A degradation rate is 99 %.4,The degradation reuse experiments of Gd-TiO₂ microsphere on bisphenol A showed: after repeated use three times little change in the degradation efficiency of the catalyst, generally about 5 %, so reuse of this material is good, there are large application prospects in practicly.In conclusion, TiO₂ and Gd-TiO₂ sphere photocatalyst can be a high efficient treatment in GLSCSPCR system of BPA, which shows good industrial application.