Activation Persulfate By Novel Catalytic Materials For Degradation Of Acidic Orange ?

In recent years,with the rapid development of the printing and dyeing industry,the demand for dyes has increased year by year.However,the production and use of dyes will generate a large amount of wastewater,which makes how to effectively treat dye wastewater has become an urgent problem to be solved.Therefore,different manganese oxide catalysts were synthesized in this paper to activate persulfate(PS)to generate sulfate radicals(SO4·-),and then the free radicals can react with the azo dye AOII to achieve the removal of target.The main research contents are as follows:1.Hydrothermal synthesis is used to synthesize Mn02 catalysts with different morphologies by controlling the synthesis time.The experimental results show that the catalytic performance of Mn02 synthesized when the hydrothermal synthesis time is 2 h is the best.However,in the subsequent experiments,the catalyst was found to have problems such as low catalytic activity,poor cycle stability and long catalytic degradation time.When MnO2 is used as a catalyst,the removal rate of AOII in the reaction is 95.5%in 180 min,and the removal rate of AOII is only 58.7%after three cycles of use.2.In order to solve the above problems,an ethanol solution was added to the reaction solution to modify Mn02 into a valence heterostructure manganese oxide(MnOx-10).This synthesis process utilizes the reducing properties of ethanol so that the ratio of manganese in different valence states can be controlled by controlling the amount of ethanol added.The MnOx has higher charge separation and electron transfer efficiency than MnO2,thereby making it have higher catalytic activity.The experimental results show that when MnOx-10 is used as a catalyst,the removal rate of AOII is 97.5%within 50 min,and the removal rate of TOC is 77.8%.The removal rate of AO? after catalyst is used for three times is still 90.3%.3.However,the experiment found that the higher the initial pH value of the wastewater solution,the lower the reaction rate with MnOx-10 as the catalyst.Therefore,the MnOx/t-ZrO2 catalyst was designed and synthesized.The solid acid t-Zr02 in the catalyst can not only create a micro-acid environment around the catalyst,so the reaction process of degrading pollutants will not be affected by the pH value of the solution but also accelerate the degradation rate of target pollutants.Therefore,the catalytic degradation process carried out by using such a catalyst can reduce the cost required for adjusting the pH value of the solution.The experimental results show that when MnOx/t-Zr02 is used as catalyst,the removal rate of AOII can reach 97.5%and the removal rate of TOC reaches 86.7%under different initial pH conditions,and the catalyst still has good catalytic activity after being used for three times.In this thesis,different manganese oxides were synthesized by simple hydrothermal synthesis,and the catalytic activity and stability of the catalyst were improved by synthesizing the manganese oxides of the valence heterostructure.The problem of the catalytic process being affected by the pH of the solution was solved by the addition of solid acid.This provides a new perspective for further improving the catalytic performance of manganese oxides.