Study On Preparation Of Aluminum-iron Loaded Montmorillonite Heterogeneous Fenton-like Catalyst And Its Application In Phenolic Wastewater Treatment

Phenol and phenolic compounds are important organic raw materials and widely used in chemical,coking and wood processing industry.Meanwhile,plenty of phenolic wastewater which is hard to biodegradable has been produced.For the treatment of phenolic wastewater,traditional purification technologies such as adsorption and biological treatment are unable to be applied on large scale because of the cost and technical restrictions.Therefore,developing efficient and low-cost technologies for phenolic wastewater is still full of challenges.In recent years,advanced oxidation technology,especially the clay-supported Fenton-like oxidation technology,has drawn much attention due to its advantages,such as wide source,low cost and no secondary pollution.The aim of this study is to develop a new type of aluminum-iron loaded montmorillonite Fenton-like catalyst for the treatment of phenolic wastewater.The main research contents are as follows:?1?The preparation methods of different Al-Fe loaded montmorillonite Fenton-like catalysts were compared,as well as the different raw materials,the ratio of Al/Fe and the calcination temperature.The results show that employing montmorillonite and metallic iron as the carrier and active component respectively,the optimal catalyst could be prepared by coprecipitation and wet impregnation for the loading of Fe and Al separately.In that process,the molar ratio of FeCl₃,FeCl₂ and AlCl₃ was 1:2:3,the molar ratio of Al/Fe was 1:1,the calcination temperature was 500?and the calcination time was 6 h.?2?For the composition and structural characterization analysis of the selected Al/FeM-500 catalyst,TEM,XRF,XRD,FTIR,XPS and BET has been adopted.The results reveal that the loading metals exist in the form of?-Fe₂O₃,Al₂O₃ and Fe²⁺,with a small amount of agglomeration,but well distributed on the carrier.The impregnated Al³⁺ions can enter the interlayer of the montmorillonite and expand the distance between layers in order to improve the accessibility of active sites.?3?The selected Al/FeM-500 catalyst was used for the treatment of simulate phenolic wastewater by heterogeneous Fenton-like oxidation.And the optimal treatment conditions were optimized from the initial pH of the solution,the amount of H₂O₂,the concentration of the catalyst and the initial concentration of phenol.Under the optimal conditions,the initial pH was4.5,the amount of H₂O₂ was 45 mmol/L,the dosage of the catalyst was 0.5g/L and the reaction temperature was 30?,the removal rate of phenol and TOC can reach 100%and 49%within 120min.Meanwhile,the leaching of Fe³⁺and Al³⁺were 0.71 mg/L and 2.66mg/L,respectively.