Preparation Of Montmorillonite Modified Catalyst And The Efficiency Study Of Catalytic Ozonation

Water resource is seriously scarce in our country,the industrialization brings economic development,and it also brings the environmental problems,especially water pollution.Persistent organic pollutants(POPs)in water have attracted much attention.Heterogeneous catalytic ozonation has been widely recognized in the field of water treatment.This technology has the advantages of high oxidation rate,simple process and no secondary pollution.In this paper,use the impregnation method to prepare the modified montmorillonite catalysts.Then,by means of XRD,XPS,SEM,FTIR,BET and TG-DSC to analyse the prepared catalyst.Taking bisphenol A as the target,the degradation rate as the experimental index,to screen out the catalysts with high catalytic activity,and the optimum conditions for the preparation of the catalysts were obtained.The results showed that the degradation efficiency of catalytic ozonation system was better than that of single ozonation system,and the optimum conditions for two kinds of metal oxide modified montmorillonite were as follows: 15% of the loading capacity and 400 degrees celsius of the baking temperature.The performance research of the catalytic ozonation systemis performed by the catalyst screened out before,the factors include the concentration of bisphenol A,concentration of ozone,catalyst concentration and pH of the system,the results showed that when the concentration of bisphenol A decreased,the degradation rate of bisphenol A in the system increased;the increasing concentrationof ozone is helpful to degradation of bisphenol A;with the increasing of the concentration of catalyst in the system,the degradation of bisphenol A first increased with the increasing catalyst concentration,while the concentration reaches a certain value,with the increasing catalyst concentration decreased;when the pH of the system is alkaline,the degradation effect of bisphenol A is better.The ozone mass transfer of the ozone system and ozone catalytic system were compared,montmorillonite based catalyst increased the transfer rate of the ozone from the gaseous phase to the liquid phase and increased the utilization rate of ozone,as a result,the degradation of bisphenol A rate increased.The hydroxyl radical in two systems is detected by DMPO and tert-butyl alcohol,the results showed that both ozone system and ozone catalytic system have hydroxyl radical,butthe amount of hydroxyl radical in the catalytic ozonation system is larger.Because the oxidation ability of hydroxyl radical is higher than ozone,the removal rate of TOC in the catalytic ozone system is significantly higher than that of the ozone system.