A Simple Aqueous Solution Based Chemical Methodology for Preparation of Mesoporous Alumina: Efficient Adsorbent for Defluoridation of Water

In this paper, we report a simple aqueous solution based chemical method for preparation of mesoporous gamma-Al2O3 which can be used for removal of fluoride ions from water. The synthesized Al2O3 and commercial Al2O3(Grade AD101-F, ACE Manufacturing and Marketing, Baroda, India) were characterized by using powder x-ray diffractometer, N-2 adsorption-desorption surface area and pore size analyzer, and high resolution transmission electron microscope. Synthesized Al2O3 contains a wormhole-like mesoporous structure with 358.7m(2)g(-1) Brunauer-Emmett-Teller (BET) surface area and 0.8cm(3)g(-1) pore volume. Batch adsorption studies were performed to determine the fluoride adsorption capacity of Al2O3. The effect of different parameters such as contact time, initial fluoride concentration, pH, and adsorbent dose was studied to understand the fluoride adsorption behavior of the synthesized Al2O3 under various conditions. The kinetics results showed that the fluoride adsorption on synthesized Al2O3 followed pseudo-second-order kinetics. Adsorption equilibrium data fitted well to the Freundlich equation and indicated multilayer adsorption of fluoride on the surface of Al2O3. Synthesized Al2O3 demonstrated significantly improved fluoride adsorption capacity and faster kinetics than commercial Al2O3.