Removal of methylene blue from aqueous solution using chitosan-g-poly (acrylic acid)/montmorillonite superadsorbent nanocomposite

Batch adsorption experiments were carried out for the removal of methylene blue (MB) cationic dye from its aqueous solution using chitosan-g-poly(acrylic acid)/montmorillonite (CTS-g-PAA/MMT) nanocomposites as adsorbent. The factors influencing adsorption capacity of the nanocomposite such as initial pH value (pH(0)) of the dye solution, MMT content (wt%), weight ratio (wr) of AA to CTS and adsorption temperature (T) were investigated. The results showed that the wr of AA to CTS of the nanocomposites have great influence on adsorption capacities and introducing a small amount of MMT Could improve adsorption ability of the CTS-g-PAA. The adsorption behaviors of the nanocomposite showed that the adsorption kinetics and isotherms were in good agreement with pseudo-second-order equation and the Langmuir equation, respectively, and the maximum adsorption capacity is 1859 mg/g for CTS-g-PAA/MMT with wt% of 30% and wr of 7.2:1. The desorption studies revealed that the nanocomposite provided the potential for regeneration and reuse after MB dye adsorption. (C) 2008 Elsevier B.V. All rights reserved.