Preparation Of Fe2O3-CeO2-TiO2/γ-Al2O3as Catalyst For Catalytic Wet Air Oxidation Of Delayed Coking Waste Water Under Room Condition

The main point of this paper is to study how to produce Fe2O3-CeO2-TiO2/γ-Al2O3catalyst and how to degrade wastewater,including methyl orange and Na2S, under the condition of normal temperature and atmospheric pressure, the author carried out catalytic oxidation degradation of wastewater by using the best catalyst. It is a basic research on wet catalytic oxidation degradation of wastewater under the condition of normal temperature and atmospheric pressure by using the catalyst. The main contents of the research and the conclusions are as follows:1. Investigate the optimal condition of producing the catalyst. Take two-step impregnation and calcination method to produce the catalyst. The optimal calcining temperatures of the first step and the second step are450℃and400℃. The optimal contents of all the components in the catalyst are respectively:2.168%、0.291%、0.161%.2. Research on the effect of the catalyst,Fe203-Ce02-Ti02/γ-Al203,depredating methyl orange under the condition of normal temperature and atmospheric pressure. Take the research method of changing single factor to improve the optimal operation condition under which Fe2O3-CeO2-TiO2/γ-Al2O3works on methyl orange,in order to make the optimal catalyst working in the perfect condition. The perfect condition is: pH value of3.5,ventilation with the amount of air (antioxidant) is0.7L/min,catalyst dosing quantity of3g/100ml wastewater (concentration for500mg/L). In this opera-tion condition,the degradation effect of Fe2O3-CeO2-TiO2/γ-Al2O3on methyl orange can reach96%,which proves that under a mild condition,the catalyst can degrade methyl orange very well.3.Demonstrate Fe2O3-CeO2-TiO2/γ-Al2O3by using BET,XRD and infrared spectrum,ultraviolet spectrum and try to find the structure of catalyst. Demonstrate the process of Fe2O3-CeO2-TiO2/γ-Al2O3degrading methyl orange and analyze the mechai-sm of the catalytic oxidation degradation.4. Study the service time of the catalyst Fe2O3-CeO2-TiO2/γ-Al2O3,the reason for the catalyst’s deactivation and conditions to regenerate it. After five reactions,the effect degradation of the catalyst,Fe2O3-CeO2-TiO2/y-Al2O3,decreased to61.95%. The author tried a variety of methods to regenerate the catalyst and found that cleaned the catalyst for five minutes by using5%hydrochloric acid after the reaction and calcined for3h at400℃This method can make the catalysts’activity nearly returning to the activity of fresh catalysts. The degradation effect on methyl orange reached91%.5. A study of catalyst Fe2O3-CeO2-TiO2/y-Al2O3degrading wastewater containin-g Na2S. The Catalyst has a certain degrading effect on wastewater. The more reactants in the wastewater,the bigger of its removal rate. When the concentration of the react-ants in wastewater is less than200mg/L, the removal rate can reach100%. The auth-or preliminarily studied the cause of the catalyst’s deactivation.6. A research on the catalyst,Fe2O3-CeO2-TiO2/y-Al2O3,degrading delayed coking wastewater.(1)Through the sand filter,flocculation,the author removed the big particle materials from delayed coking wastewater and evaluated the quality of the rest water. The author studied the choice of flocculant and its dosage,with FeSO4·7H2O its dosing quantity for7g,COD removal rate achieving maximum,36.16%.The removal rate of sulfide is60.92%. The author used catalyst Fe2O3-CeO2-TiO2/y-Al2O3to degrade the pretreated water and found that in the experiment design conditions,CODcr removal rate is not very ideal,and when the amount of catalyst is for6g,CODcr removal rate is only30.74%.(2)A research on the catalytic oxidation degradation of the catalyst on low concentration delayed coking wastewater. Because the concentration of the reacta-nts in wastewater influences a lot on the effect of degradation of effect,at first,the author used Fenton to degrade the delayed coking wastewater with high concentration. In the Fenton reaction,when H2O2dosing quantity is for160mmol/L and [Fe2+]/[H2O2] is for1:10, the removal rate of CODcr in the delayed coking wastewater reach-ed88.0%.And then the catalyst degraded the rest delayed coking wastewater with a dosing quantity for3g,the biggest removal rate of CODcr is48.61%.(3)The biodegra-dability of the delayed coking wastewater improved a lot,with BOD/COD reaching0.48after a series treatments,sand filtering,fiocculation,Fenton oxidation and the cata-lytic oxidation of the catalyst Fe2O3-CeO2-TiO2/y-Al2O3.