Preparation, characterization and adsorption evaluation of spherical mesoporous Al-MCM-41 from coal fly ash

The present study offers an economic synthesis of AI-containing spherical mesoporous Al-MCM-41 material from coal fly ash by one step. The texture and composition of the samples were characterized by XRD, N-2 adsorption, FE-SEM, TEM, FT-IR, and (27)AI MAS NMR. As a catalyst, the effects of ethyl acetate to the diameter and sphericity of the samples have also been investigated. The results show that the sample Al-MCM-41-10 prepared at the amount of ethyl acetate value of 10 mL displays the largest BET surface area (525.0 m(2)/g) and pore volume (0.71 cm(3)/g). Using this material as adsorbent for methylene blue (MB) removal, the adsorption capacity reaches 277.78 mg/g. The effects of pH, contact time, initial adsorbate concentration and temperature were evaluated by batch of adsorption experiments. Adsorption kinetics and isothermal adsorption studies showed that the pseudo-first-order model and the Langmuir isotherm fitted the experimental data quite well, indicating that the MB adsorption onto Al-MCM-41-10 adsorbent should be monolayer and chemical adsorption with the surface reaction. Thermodynamic analysis indicated an exothermic nature of adsorption and a spontaneous and favorable process. Our present study shows an economic way to treat MB using the industrial solid waste of coal fly ash. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.