Microwave Induced Catalyic Degradation Of Methyl Orange Solution

Microwave induced catalytic oxidation process has many advantages such as improved speed of reaction, the high degree of degradation, no secondary contamination to the environment and easy to operate. In this paper, granular active carbon (GAC), Fe-B nanoparticles (nano-FeB), Fe2O3/AC catalyst and Fe2O3/GC catalyst were prepared and the methyl orange simulated azo dye wastewater was treated by microwave induced catalytic oxidation process. The relationships between the efficiency of the microwave (MW) assisted catalytic in degrading methyl orange (MO) and the influence factors of the processes was investigated. The paper study on microwave induced catalytic oxidation process mechanism by experiments and theory.The influence of various factors on the degradation efficiency was investigated. The results demonstrated that The removing efficiency of MO can be increased through increasing the MW irradiation time, MW power and catalyst dosage; The acidic condition is more favorable for the degradation MO.The degradation of MO in aqueous solution by MW irradiation in the presence of granular active carbon (GAC) was investigated. The ultraviolet and visible spectrum (UV-vis), infrared spectroscopy (IR) and scanning electron microscopy (SEM) measurements were conducted to trace the MO degradation process. It was observed that the adsorption of residual intermediate products on the surface of GAC after degradation reaction reduces the repetitive use performance of spent GAC. The regeneration of the spent GAC under MW radiation was also investigated. The results show that the activity of spent GAC can be effectively recovered by MW radiation regeneration method and 74.1% of its original activity remained after 6 reaction cycles.The degradation of MO in simulated waste water by MW irradiation in the presence of Fe-B was investigated. The influence of different treatment processes on the degradation efficiency was investigated. The results demonstrated that the MO can be efficiently removed by MW irradiation in the presence of ferrihydrite. The ferrihydrite was characterized with XRD and SEM. The results show that the ferrihydrite transformed to γ-Fe2O3 after degradation reaction. The UV-vis and IR measurements were conducted to trace the MO degradation process. It was observed that the mechanism of MO removing over ferrihydrite includes dual functions of absorption and degradation.Using carbon supported ferric as catalyst, the degradation of MO simulated wastewater by the microwave-promoted Fenton-like process has been studied. The catalysts were characterized with XRD, SEM and Energy-dispersive X-ray spectroscopy (EDS). The results show that the amorphous spherical iron oxide coated granular activated carbon and the α-Fe2O3 coated graphitic carbon. The test was conducted to evaluate the influence of various parameters on the degradation performance. The results demonstrated that the MO can be efficiently removed by MW irradiation in the presence of carbon supported ferric. The UV-vis and IR measurements were conducted to trace the MO degradation process. Results indicated that the mechanism of MO removing over Carbon supported ferric are attributed to both the absorption and degradation. MW irradiation could enhance the production of hydroxyl and thermal effect of MW promotes the whole system of reaction.