Preparation Of Al-based Highly Dispersed Catalysts And Advanced Oxidation Degradation Of Phenol Under Neutral Conditions

Advanced oxidation technology,which is one of the importanttreatment technologies for bio-refractory wastewater,which is widely used for advanced treatment or pretreatment of organic wasterwate.Fenton oxidation technology and persulfate oxidation technology are emerging advanced oxidation technology,which are favored because of their simple device,rapid response and non-selectivity.However,most of the Fenton reactions need to be carried out under the acidic conditions,and the catalytic activity is rapidly reduced under the neutral and alkaline conditions.Although the Cobalt-based catalysts can activate the persulfate reaction under the neutral conditions,the size and dispersibility of the active component nanoparticles on the catalyst affect catalytic activity.Therefore,it is necessary to prepare a green and efficient advanced oxidation catalysts.In this paper,As the supported catalysts has the advantages of gooddispersibility of active components,low metal usage,easy separation and recovery,ect.efficient heterogeneous Fenton catalysts and persulphate catalysts were prepared by loading different active components.the Al-modified porous material Al@SBA-15 is further used to improve the dispersibility of the active component,and finally the catalyst has good catalytic activity under neutral conditions.Because of the close relationship between the Fentonreaction and the persulfate reaction,This paper also compares the similarities anddifferences between the two reaction systems.The details are as follows:Al is modified on porous material SBA-15 to obtain Al-based materialAl@SBA-15,a Fenton-like catalyst was prepared by the loading of Fe and Cu for the degradation of phenol.The experimental results illustrate that the catalyst has great catalytic degradation performance for phenol under pH=7,and the removal rate of phenol can reach 98%within 1 h.The controlled experiment demonstrated that the catalyst activity was much higher than that of the catalyst without Al modification,and higher than that of Fe and Cu alone.By influencing factors analysis experiments we can make a conclusion that the optimal reaction conditions were:reaction temperature 25°C,catalyst concentration 0.2g/L,hydrogen peroxide concentration 20mM.Catalyst recycling experiments indicate that The catalyst still has high catalytic activity after 4 times cycles,and metal dissolution is at a low level.Mechanistic studies show that Al itself does not have catalytic activity,but the modification of Al can greatly improve the dispersibility of the active component,and Al can assist the active component to produce·OH degradation pollutants under neutral conditions.Preparation of Highly Dispersible Heterogeneous Persulfate Catalystfor Phenol Degradation by Co Loading in Al@SBA-15,and the similarities and differences between the samples and the non-Al modified samples were compared.The experimental results after 1 h reaction under neutral conditions show that the presence of Al can greatly improve the catalytic activity.The Al@SBA-15 supported Co catalyst can achieve a phenol removal rate of 99%,while the Al-free sample under the same conditionsjust 6%.By studying the relationship between the content of Al and the catalytic activity,it was found that Al can improve the dispersibility of the active component,Al is also capable of electron transfer with the central metal Co on the active component.,and promote the circulation of Co³⁺/Co²⁺,and accelerate the rate of the catalyticreaction.