Catalytic Ozonation For The Removal Of 4-Chlorophenol Over The Zeolite Supported MnO_x

Ozone oxidation has been widely used in the industrial wastewater treatment as the product of the ozone decomposition was harmless to the environment.But the low efficiency of ozone was the important issues that could not be ignored,catalytic ozonation could improve oxidation efficiency and there was no subsequent metal ions removal problems.It is commonly believed that the principle is promoting ozone generate more OH· to degrade refractory organic matter.In this study,the catalyst with heterogeneous zeolite loaded with MnOx were tested by the removal of 4-chlorophenol.By virtue of intensive study on the relationship between the catalyst activity and preparation conditions,such as dipping concentration and time,the right calcination temperature and calcination time.The best condition was that,dipping concentration 0.2mol/L Mn?NO₃?2 for 24h,and calcination temperature 773K for 4h.The chemical and physical properties of the catalyst MnOx/Zeolite was characterized by SEM,EDS,XRD,XPS,BET and pHzpc.Compared the results of O₃ alone,Zeolite/O₃,MnOx/Zeolite/O₃ and the absorption experiments,MnOx/Zeolite/O₃ achieved the best result of the COD removal efficiency,the 4-CP was 100%removed after 20mins detected by the HPLC.After 1h,the COD and TOC removal efficiency were 85%and 65%.Meanwhile,the catalyst was still stable during many experiments,the removal of COD and TOC were reached 80%and 62%.Influencing factors on the catalytic ozonation of 4-CP were studied.The best reaction conditions was that the concentration of the ozone was 19.58mg/L,pH 8.75,the dosages of the catalyst was 143g/?L wastewater?,reaction temperature was 20.43 ?.The COD removal of experiment results?91.56%?and accurate model prediction?92.37%?was highly similar.The analysis model was reliable and efficient.