Study On Ozone Catalytic Oxidation Catalyst And Three-dimensional Numerical Simulation Of Jet Aerator

The sewage form the industrial production has gained wide attention because it's composition is becoming more and more difficult to handle.In particular,aromatic hydrocarbon and chromogenic groups cannot been completely degraded by traditional techniques,Multiphase ozone catalytic oxidation technology which has the advantages of good degradation effect and no pollution has received wide attention.In this paper,activated carbon has been used as carrier to prepare MnFe2O4-CeO2/AC catalyst through impregnation method and thermal adsorption-coprecipitation method.The effect of multiphase ozone catalytic oxidation technology on aromatic hydrocarbon wastewater is studied.Results show that the loading of MnFe2O4 is 3 wt%and the content of Ce is 2 wt%when the activated carbon is pretreated with nitric acid at 500? for 3 hours,which produces the catalyst with the highest activity.The aromatic hydrocarbon wastewater was treated under the reaction conditions of O3 dosage 75 mg·L-1,O3 concentration 100 mg·L-1,system solution pH 9,H2O2 dosage 20 mg·min-1 and the COD removal rate in water is 72%.By characterizing the MnFe2O4-CeO2/AC catalyst,we find that the doping of Ce increases the dispersion of MnFe2O4 on the catalyst surface and the synergistic effect of these elements also inhibits the loss of active components during the reaction.After 160 hours,the active component on the catalyst does not decrease while the removal rate of COD is always maintained at around 70%.The results show that the MnFe2O4-CeO2/AC catalyst has high activity and stability.We have find that the MnFe2O4-CeO2/AC catalyst with Ti doping has a good decolorization effect on azo dyes wastewater.With the Ti doping amount of 1.5 wt%,Ti and Ce catalyst precursor calcination temperature of 550? and calcination time of 3 hours,the decolorization rate of MnFe2O4-CeO2-TiO2/AC catalyst for azo-based dye wastewater is 91.2%.In the degradation experiment of direct black wastewater,MnFe2O4-CeO2-TiO2/AC catalyst shows high catalytic activity,the decolorization rate of wastewater is maintained at around 90%,and active metal species are not detected in the processed water.In the FLUENT simulation of the jet aerator,we find that the jet aeration method can lead the gas completely with liquid.When the liquid-gas ratio is higher,the phenomenon of gas phase agglomeration in the jet aerator can be effectively avoided.At the same time,in the state of high liquid velocity,the nozzle can generate a high degree of vacuum,so that it continuously sucks in gas and breaks it into fine bubbles.It not only enhances the mass transfer efficiency between gas and liquid but also increases the efficiency of dissolved oxygen in the liquid phase.It is significant for improving the aeration mode of multiphase ozone catalytic oxidation technology in theory.