Preparation Of Novel Heterogeneous Fenton Catalyst FH-ATP And Its Application In Treatment Of Organic Wastewater

At present,wastewater treatment methods include adsorption method,membrane separation technology,electrochemical method and aerobic biological treatment.Compared with the above treatment methods,Fenton reaction catalysis has the obvious advantages of high degradation efficiency and simple equipment.Some disadvantages of homogeneous Fenton system such as easy secondary pollution of iron and narrow reaction p H range affect the popularization of homogeneous Fenton catalyst in industrial production.In contrast,Heterogeneous Fenton catalyst has the advantages of wide reaction p H range,recyclability and environmental protection,and has high economic benefits and good application prospects in industrial production,therefore it has attracted widespread attention.In this paper,a novel heterogeneous Fenton catalyst（FH-ATP）was synthesized by impregnation and freeze-drying method using ATP（attapulgite）as the carrier and FH（two-line ferrihydrite）as the active material to remove methylene blue（MB）.The microscopic morphology and structure composition of the FH-ATP were studied by SEM,TEM,FT-IR,XRD and BET means.Scanning electron microscopy images showed that distinct FH particles could be seen on the surface of ATP,indicating that FH had been successfully loaded onto ATP.The elemental composition of the catalyst and the chemical valence state of iron were studied by XPS.The N₂ adsorption and desorption isotherms and their pore size distribution demonstrated that the isotherms of the catalyst belonged to Type IV.The obvious H2-type hysteresis ring indicated that the composite had a mesoporous structure,which was beneficial to increase the contact area between the catalyst and MB,thereby improving the decolorization efficiency of the catalyst to MB.In order to further study the effect of the concentration of catalyst,the amount of hydrogen peroxide and the p H on the decolorization rate of MB,relevant experiments were carried out.Under the optimal operating conditions of 2.0 g/L of 10%FH-ATP,120 mg/L H₂O₂ and p H 7.0,the MB decolorization efficiency could reach 99.8%within 70 min.The removal efficiency still reached about 70%after 4 cycles.The decolorization experiment results of the catalyst on different dyes under the optimal conditions showed that the decolorization efficiency of the catalyst for Rh B and MO was 80.7%and 56.5%within 70min,respectively,indicating that the heterogeneous Fenton catalyst could effectively degrade a variety of dyes.Furthermore,active radical（·OH）trapping experiments and EPR spectroscopy studies suggested that·OH played a major role in the mineralization of MB.Therefore,the prepared catalyst FH-ATP has the advantages of high efficiency,recyclability,and low cost in the process of removing organic dyes,which provides a novel and efficient heterogeneous Fenton catalyst for the effective removal of organic dyes in solution.