Efficient adsorption of methylene blue on an alginate-based nanocomposite hydrogel enhanced by organo-illite/smectite clay

The mixed-layer illite/smectite clay (IS) was organified and compounded with the sodium alginate-g-poly(sodium acrylate-co-styrene) (NaAlg-g-p(AA-co-St)) matrix to prepare a NaAlg-g-p(AA-co-St)/org-ano-I/S nanocomposite for adsorbing methylene blue (MB). Fourier transform infrared spectroscopy, Xray diffraction and scanning electron microscope analyses confirmed the organification of I/S and the formation of the nanocomposite. The adsorption properties of the nanocomposite for MB was systematically investigated by optimizing the influence parameters, such as the organification degree of I/S, the pH of MB solution, contact time, initial concentration of MB and temperature. It was found that the nanocomposite can rapidly adsorb MB with a higher adsorption capacity (1843.46 mg/g), and the adsorption isotherm and kinetics were described well by Langmuir isotherm model and Ho's pseudo-second-order model, respectively. The moderate organification (0.25 E) of I/S contributes to enhance the adsorption capacity of the nanocomposite for MB, which renders the nanocomposite promising for the efficient removal of cationic dyes. (C) 2013 Elsevier B.V. All rights reserved.