Preparation Of Micron-scale Supported TiO₂Catalysts And Its Photocatalytic Degradation Characteristics

This thesis focuses on the problem of the degradation process of wastewater byTiO₂photocatalytic technology. Aimed at easing the problem of nanometer TiO₂powder catalyst difficult separation and recovery, easy reunion inactivation in thewater treatment process. Photocatalytic-biochemical collaborative process deal withthe problem of high concentration pharmaceutical wastewater and conducted in-depthstudy. Overview of the thesis content from the following three aspects:（1） Using the sol-gel method and pore generated prepared micron supportedTiO₂catalysts and the catalyst preparation conditions and its characteristics werestudied. Experimental results show that: the micron carrier of MCM-41the TiO₂massloading capacity of30%, the calcination temperature of600℃, the calcining time2hdeveloped micron highest photocatalytic activity of TiO₂, this catalyst has goodactivity, stability and repeated recycling rates. Characterized by its analysis shows,prepared micron TiO₂Catalysts uniform particle size distribution, average particlesize of16μm, the load on the MCM-41zeolite TiO₂anatase crystalline form stablemicron catalyst in the high-temperature calcination. After molding, the carrier channelis still visible collapse phenomenon generated. Experiments show that the catalyticactivity of factors: The optimum dosage of2g/L, its catalytic rate is slower with theincrease of the concentration of pollutants in the acidic medium, the appropriateconcentration of the highest catalytic activity of the pollutants H₂O₂can significantlyimprove the catalytic activity of TiO₂.（2） Through the catalyst activity evaluation device design with suspendedphotocatalytic-membrane separation reactor investigate the micron supported TiO₂catalyst suspension characteristics, characteristics of membrane fouling and itsseparation characteristics of the suspension reactor.The study showed that: thecatalyst activity evaluation device can be a good expression of the catalytic activity ofthe catalyst in the suspension-type reactor.Suspended photocatalytic-membraneseparation reactor bottom aeration rate of0.3m³/h, the suspension characteristics ofthe catalyst is the best. And the catalyst, compared to nano-catalyst, not only has goodseparation characteristics, but also the characteristics of membrane fouling can begreatly reduced, to extend the life of the membrane separation module of the micronlevel. （3） The degradation characteristics of high concentration pharmaceuticalwastewater by micron photocatalytic TiO₂catalyst,The study results show that: thephotocatalytic/SBR/flocculation combined process can significantly reducepharmaceutical wastewater CODCr, improve wastewater biodegradability. Thephotocatalytic degradation of pharmaceutical wastewater kinetic studies showed: thehigher the light intensity, the catalytic reaction followed second-order kineticsreaction, with the weakening of the light intensity, the photocatalytic degradation ofpharmaceutical wastewater reaction tends to be the three kinetic reaction.