Microwave synthesized xanthan gum-g-poly(ethylacrylate): An efficient Pb2+ ion binder

Microwave induced emulsion copolymerization of ethylacrylate and xanthan gum resulted in copolymer samples of different % grafting (%G). The synthesis was done in the presence of catalytic amount of KPS as an initiator and the adsorption behavior of the copolymer (360%G) was investigated by performing both the kinetics and equilibrium studies in batch conditions. The copolymer was characterized by different techniques. Several experimental parameters were varied to optimize the adsorption conditions. The most favorable pH for the adsorption was pH 5, and at this pH the adsorption data were modeled using Langmuir and Freundlich isotherms. On the basis of the Langmuir model, Q(0) was calculated to be 142.86 mg g(-1) for microwave synthesized copolymer (mwXG-g-PEA). The sorption by mwXG-g-PEA followed pseudo second-order kinetics where a linear plot of t/(qt) versus t was obtained, the correlation coefficient (R-2) and rate constant at 100 mg L-1 Pb(II) being 0.994 and 3.013 x 10(-4) g/(mg min), respectively. (C) 2012 Elsevier Ltd. All rights reserved.