Characteristics of cerium-aluminum-manganese mixed oxides and their performance in adsorbing methyl violet dye from an aqueous solution

摘要

In this work, CeAl and CeAlMnx oxides (x = 0.1, 0.3, 0.5 and 0.7) were prepared using a co-precipitation method and their use for removal of methyl violet dye from an aqueous solution was investigated. The characteristics of the mixed oxides were determined using XRD, FT-IR, UV-vis DRS, SEM and EDX. It was found that cerium, aluminum and manganese ions were homogeneously incorporated into the cubic fluorite structure of CeO2. Moreover, the mixed oxides were found to consist of small grains containing pores, which resulted in a large surface area to volume ratio. Batch adsorption studies were performed to determine the contact time required to achieve equilibrium. The removal of dye by CeAl and CeAlMnx (x = 0.1 and 0.3) attained equilibrium after 60 min, while oxide samples with higher manganese fractions achieved equilibrium in 120 to 150 min. Based on the isotherm data, the adsorption behavior of CeAl was found to follow a Langmuir isotherm (R-2 = 0.9951) with a maximum adsorptive capacity of 2.35 mg/g. Results show that the Freundlich model best describes the adsorption of MV dye onto all CeAlMnx formulations.