Microwave assisted preparation of n-butylacrylate grafted chitosan and its application for Cr(VI) adsorption

Biopolymers such as chitosan possess excellent properties suited for varied applications. In this work, we describe a novel microwave assisted method for the preparation of n-butylacrylate grafted chitosan adsorbent and its utility for the adsorption of chromium(VI). A 3 min irradiation time was enough to prepare the adsorbent, and techniques such as FT-IR, powder XRD, SEM and EDS were used for comprehensive characterization. The adsorption was effective at pH 3.5 with 25 mL of 20 ppm Cr(VI) solution. Langmuir, Freundlich, Dubinin-Radushkevich, Temkin, Elovich and Redlich isotherms were studied in detail. The Delta G, Delta H and Delta S parameters were evaluated to understand the adsorption thermodynamics. The adsorption involves the interaction of Cr(VI) with the hydroxyl and amino groups in chitosan. (C) 2014 Elsevier B.V. All rights reserved.