Experimental Evaluation Research On Refining Waste Catalyst Used In Simulating Refinery Wastewater Treatment

The rapid development of the oil refining industry has led to a rapid increase in the output of spent oil refining catalysts.The conventional disposal of spent catalysts is a problem faced by the oil refining industry.Fluid Catalytic Cracking（FCC）waste catalysts and Hydrogen Cracking（HC）waste catalysts have a large output.If the waste catalysts can be reused with high-added value,it will be beneficial to clean production and circular economy in the oil refining industry.National and local wastewater discharge standards are becoming increasingly stringent,and compliance with wastewater discharge is another challenge facing by the oil refining industry.Adsorption and catalytic ozone oxidation are the preferred technologies for treating oil refining wastewater due to their high efficiency,low cost,and easy operation.In this study,four catalysts including FCC,HC and waste agents s FCC and s HC were used to adsorb and catalyze refractory organic pollutants（ROCs）in simulated refining wastewater.The mechanisms of adsorption and catalyzed ozone oxidation（COP）were investigated.The results showed that the four catalysts had good adsorption effects on nitrobenzene and p-nitrophenol.The adsorption effect of s FCC and s HC were better than that of FCC and HC.The adsorption performance of s FCC and s HC on the four pollutants were followed by nitrobenzene>p-nitrophenol>benzoic acid>phenol,and the removal rates are 72%,33%,10%,1%and 92%,53%,9%,1%,respectively,under the initial pollutant concentration of 100 mg/L and catalyst addition of 3 g/L.The initial p H had little effect on the adsorption of nitrobenzene,but had a certain effect on the adsorption of benzoic acid and p-nitrophenol,which could be due to the different the adsorption mechanism.In addition,all adsorption processes were in accordance with Langmuir model and pseudo-second-order adsorption kinetics.The catalytic ozone oxidation results indicated that only s HC showed catalytic capacity on p-nitrobenzene and p-nitrophenol,and TOC removal rate is 24%and 11%higher than ozone oxidation alone.Moreover,the catalytic oxidition can be achieved in a large initial p H range（2-11）.ESR analysis indicated that there were·OH and ¹O2 in the solution.In addition,O₃^-and O₂^-formed from O₃and other free radicals including HO₃·^-,HO₂·^-,HO₃·^-,and HO₂·^-that are formed by the interaction of free radicals and protons may all play a role in catalytic ozone oxidation.