Removal of methyl violet dye by adsorption onto mesoporous mixed oxides of cerium and aluminum

Abstract

In this study, the adsorption efficiency of methyl violet dye onto Ce03Al07, Ce05Al05, and Ce07Al03 mixed oxides was investigated. The properties of Ce/Al oxides were determined by scanning electron microscope, X-ray diffraction, FT-Raman spectrometry, and N2 adsorption–desorption isotherms. Characterization tests showed that synthesized Ce/Al oxide with fluorite has pure cubic structure of mesoporous nature and non-uniform in size with rough surface. Moreover, the surface areas of Ce/Al oxides were observed to decrease with increase in cerium content. The batch adsorption experiments were performed at 25°C and various parameters including solution pH, contact time, and initial dye concentration were studied. The dye adsorption of Ce03Al07 mixed oxide attained equilibrium at 15 min, which was faster than that of Ce05Al05 and Ce07Al03. The equilibrium adsorption data were analyzed using Langmuir, Freundlich, and Temkin isotherms. The adsorption behavior of methyl violet onto Ce03Al07 (R2 = 0.9739) was found to follow the Langmuir isotherm, providing maximum monolayer adsorptive capacity of 25 mg/g. On the other hand, the adsorption of methyl violet onto Ce05Al05 (R2 = 0.9581) and Ce07Al03 (R2 = 0.9894) followed the Freundlich isotherm.