Removal of methylene blue from aqueous solution using nanoporous SBA-3

The adsorption behavior of methylene blue from aqueous systems onto mesoporous SBA-3 has been studied. Batch experiments were carried out to measure the adsorption as a function of contact time, initial concentration (50-150 mg L-1), pH (4-12), and temperature (303, 313 and 323 K). The equilibrium of the process was achieved within 1 h. The sorption of methylene blue on the mesoporous silica SBA-3 slightly increases with increasing pH, and temperature, indicating an endothermic process. Adsorption isotherms were fitted with the Langmuir, Freundlich and Temkin models. The kinetic data were analyzed using pseudo-first-order and pseudo-second-order models. The adsorption kinetics of methylene blue on mesoporous SBA-3 matched well with pseudo-second order kinetic model. (C) 2010 Elsevier B.V. All rights reserved.