The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3&l...The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3</sub> NPs was prepared and characterized by SEM, TEM, XRD and FTIR analysis. The effect of pH, dosage of adsorbent, contact time, temperature, and the initial concentration of dye was investigated. The maximum amount of dye removal found about 99.36% at pH4, the adsorption dose 1g/L, with the initial dye concentration of 100 mg/L, and the temperature of 25°C, with contact time 120 min. The adsorption behavior of the eosin yellow dye is applicable to Langmuir isotherm model, with the maximum sorption capacity of 47.78 mg/g of γ-Al<sub>2</sub>O<sub>3</sub>. The kinetic data also described by the pseudo-second-order model with a correlation coefficient (0.9999), and the mechanism of the process showed a multi-linear steps and the intra-particle diffusion was not only rate controlling step. The adsorption process was endothermic with positive enthalpy of 121.8 kJ/mol, and showed spontaneous process with a mean free energy -5.19 kJ/mol, and increase randomness, 369.77 J/mol. k, at the adsorbent solution interface. The adsorption process was chemisorption in nature The activation energy estimated from Arrhenius and modified Arrhenius is 40.9 kJ/mol, 106.37 kJ/mol respectively. The sticking probability of EY onto Al<sub>2</sub>O<sub>3</sub> NPs very high estimated from the value of S* < 1, (4.82E-19).展开更多
Polyoxometalate (POM) catalysts with different trivalent hetero ions (Mn+ = Fe3+, Al3+, and Cr3+) were prepared by incipient wetness impregnation method and supported on different zeolites namely, NaY, ZSM-5 and Morde...Polyoxometalate (POM) catalysts with different trivalent hetero ions (Mn+ = Fe3+, Al3+, and Cr3+) were prepared by incipient wetness impregnation method and supported on different zeolites namely, NaY, ZSM-5 and Mordenite. The intended catalysts samples were distinguished by X-ray diffraction, FTIR and surface texture measurements. The data given disintegration in the crystallinity of zeolite structure, enlarge in particle size and new phases of metal oxides Al2(MoO4)3 and Fe2(MoO4)3 were exposed by XRD and FTIR techniques. These phases caused widening of pores of the employed zeolites and change of the surface texture. The physical changes indicate the considerable interaction of polyoxomolybdate with the zeolite structure. The assessment of the catalytic activity was thorough by applied the photocatalytic degradation of direct blue 1 dye (DB1) in existence of H2O2 as a green oxidant. The catalytic activity of Mn+Mo-ZSM-5 sample is higher than that of Mn+Mo-Y or Mn+Mo-Mord.展开更多
文摘The adsorption behavior of eosin yellow (EY) from aqueous solution onto γ-Al<sub>2</sub>O<sub>3</sub> nanoparticles in batch technique was studied. γ-Al<sub>2</sub>O<sub>3</sub> NPs was prepared and characterized by SEM, TEM, XRD and FTIR analysis. The effect of pH, dosage of adsorbent, contact time, temperature, and the initial concentration of dye was investigated. The maximum amount of dye removal found about 99.36% at pH4, the adsorption dose 1g/L, with the initial dye concentration of 100 mg/L, and the temperature of 25°C, with contact time 120 min. The adsorption behavior of the eosin yellow dye is applicable to Langmuir isotherm model, with the maximum sorption capacity of 47.78 mg/g of γ-Al<sub>2</sub>O<sub>3</sub>. The kinetic data also described by the pseudo-second-order model with a correlation coefficient (0.9999), and the mechanism of the process showed a multi-linear steps and the intra-particle diffusion was not only rate controlling step. The adsorption process was endothermic with positive enthalpy of 121.8 kJ/mol, and showed spontaneous process with a mean free energy -5.19 kJ/mol, and increase randomness, 369.77 J/mol. k, at the adsorbent solution interface. The adsorption process was chemisorption in nature The activation energy estimated from Arrhenius and modified Arrhenius is 40.9 kJ/mol, 106.37 kJ/mol respectively. The sticking probability of EY onto Al<sub>2</sub>O<sub>3</sub> NPs very high estimated from the value of S* < 1, (4.82E-19).
文摘Polyoxometalate (POM) catalysts with different trivalent hetero ions (Mn+ = Fe3+, Al3+, and Cr3+) were prepared by incipient wetness impregnation method and supported on different zeolites namely, NaY, ZSM-5 and Mordenite. The intended catalysts samples were distinguished by X-ray diffraction, FTIR and surface texture measurements. The data given disintegration in the crystallinity of zeolite structure, enlarge in particle size and new phases of metal oxides Al2(MoO4)3 and Fe2(MoO4)3 were exposed by XRD and FTIR techniques. These phases caused widening of pores of the employed zeolites and change of the surface texture. The physical changes indicate the considerable interaction of polyoxomolybdate with the zeolite structure. The assessment of the catalytic activity was thorough by applied the photocatalytic degradation of direct blue 1 dye (DB1) in existence of H2O2 as a green oxidant. The catalytic activity of Mn+Mo-ZSM-5 sample is higher than that of Mn+Mo-Y or Mn+Mo-Mord.
