Preparation of mesoporous Al-MCM-41 from natural palygorskite and its adsorption performance for hazardous aniline dye-basic fuchsin

A promising mesoporous Si-Al material, Al-MCM-41 was successfully prepared by alkali calcination leaching of natural palygorskite, and sequent hydrothermal synthesis coupled with calcination. The morphology, structure, surface area and pore-size distribution of the material were characterized by scanning electron microscopy, small-angle X-ray diffraction and N-2 adsorption-desorption isotherms. The Al-MCM-41 possessed better crystallinity and larger specific surface area with CTAB/SiO2 mass ratio of 0.1:1, pH of 5, crystallization temperature of 110 degrees C, crystallization time of 12 h and calcination of 550 degrees C for 5 h. The Al-MCM-41 was used as an adsorbent for the removal of hazardous aniline dye-basic fuchsin from water. Adsorption kinetics and isotherms analysis indicated that adsorption of basic fuchsin onto Al-MCM-41 followed pseudo-first-order model and Langmuir adsorption isotherm. In addition, intra-particle diffusion was rate determining step of the adsorption process. The results demonstrated that the as-synthesized Al-MCM-41 had potential applications in the treatment of waste water. (C) 2016 Published by Elsevier Inc.