Uptake of an anionic dye from aqueous solution by aluminum oxide particles: Equilibrium, kinetic, and thermodynamic studies

Abstract Naturally occurring, abundant alumina particles were used as a low-cost and eco-friendly adsorbent for the removal of Eriochrome Black T (EBT) dye from an aqueous environment. The surface morphology, crystallinity and elemental analysis composition of the alumina before and after the adsorption process were investigated using SEM-EDX, FTIR and DRX techniques. The alumina surface charge was examined by the electrokinetic measurement. The impact of the physico-chemical factors on the adsorption process was studied. The adsorption experiments were performed using a batch reactor. The fitted models were plotted for adsorption kinetic and isotherm studies based on the experimental results. The adsorption data were well described by a pseudo-second order kinetic model, and the adsorption isotherms agreed well with the Langmuir model. The maximum adsorption capacity (qmax) of alumina for the EBT dye was found to be 45 mg/g, corresponding to a removal percentage of 71%. The EBT adsorption phenomena was endothermic and spontaneous. The regeneration tests indicated that the alumina reveal an superb recycling capability. Therefore, this result shows that the alumina particles can be applied as a natural encouraging adsorbent for the removal of anionic dye from aqueous solution. The EBT dye adsorption mechanism can be controled by electrostatic attractions.