Abstract
Multiwalled carbon nanotubes (MWCNTs) were physically mixed with biopolymer chitin and magnetite to form a magnetic nanocomposite. The produced MWCNTS/chitin/magnetite (MCM) nanocomposite was characterized using scanning electron microscopy and surface-area analysis, and the magnetic properties were measured using a vibrating-sample magnetometer. The results revealed homogenous distribution of the chitin and magnetite nanoparticles within the MWCNTs in the MCM nanocomposite. The MCM nanocomposite was used to study the removal/adsorption of the well-known organic dye Rose Bengal (RB). The effect of different adsorption parameters was studied and optimized. The adsorption process was studied at different temperatures and the results were analyzed kinetically. Results revealed that the adsorption followed the pseudo-second-order kinetic model. Also, it was found that the adsorption of RB occurred in different steps including the diffusion of RB through the boundary layer to the external surface of the MCM nanocomposite, intraparticle diffusion, and adsorption of RB through the MCM nanocomposite particles. The adsorption was analyzed thermodynamically and results revealed spontaneity of the adsorption as the Delta G degrees value was negative and endothermic in nature as the Delta H degrees value was positive, and associated with the increase in the randomness as the Delta S degrees value was positive. (C) 2013 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.