Preparation Of PrFe_xCo_1-xO₃/MMT And CWPO Degradation Of Salicylic Acid Wastewater

China’s industry has developed rapidly in recent years,and the pharmaceutical industry has received more and more attention.The wastewater produced in the pharmaceutical process has the characteristics of refractory degradation,high COD value,and great harm to the human body and the environment.Salicylic acid wastewater is common pharmaceutical wastewater.In this paper,catalytic wet peroxide oxidation（CWPO）was used to degrade it,and the relevant conditions were optimized to improve the degradation effect of wastewater as much as possible.The perovskite active components PrFe_xCo_1-xO₃ were prepared by two different methods,and the active components were loaded on pillared montmorillonite by different loading methods.A series of characterization methods and COD and ADMI removal rates of salicylic acid wastewater were used to judge the differences in the catalyst composition,micromorphological structure,and reactivity at different preparation conditions,and screened out the most suitable conditions.The test results showed that when the sol-gel method is used to prepare the active components,the solid melting method is used as the loading method,the Co/Fe molar ratio is7/3,the loading amount is 33wt%,the obtained catalyst active components are well dispersed,its specific surface area is 128.627m²/g.Using this catalyst to degrade salicylic acid wastewater by CWPO,the COD removal rate of wastewater was 67.7%and the salicylic acid removal rate was 85.84%.The degradation process conditions of salicylic acid wastewater were optimized,and the controlled univariate method was used to degrade the salicylic acid wastewater with an initial concentration of 100 mg/L,using COD and ADMI removal rates as indicators,and adjusting different conditions（temperature,catalyst dosage,the amount of H₂O₂,initial p H,etc.）to obtain a suitable range of process conditions.The Design-export software was used to optimize reaction conditions,and the direct search method was used to predict the response value.The predicted reaction conditions were as follows:0.159ml of H₂O₂ and 0.056g of catalyst were added,the temperature was 80°C.The experimental verification results were:the COD removal rate was 88.91%,the salicylic acid removal rate was 98.77%,and the experimental value was relatively close to the predicted value.The mechanism and kinetics of the CWPO reaction were discussed,and it was concluded that HO·was the main group in the CWPO reaction,and free HO·has stronger oxidation.The whole degradation process conformed to the pseudo-first-order kinetic equation,and catalysis was dominant,while adsorption was weak.