Novel chitosan blended polymers for the removal of rose bengal dye: Adsorption isotherms, kinetics and mechanism

Rose bengal (RB), a synthetic dye, discharges into the environment and is harmful to the land as well as to the aquatic water bodies; therefore it is important to safeguard the environment. For the adsorption of rose bengal dye, chitosan being a good biosorbent is blended with two different polymers namely polyvinyl alcohol (PVA) and polyacrylonitrile (PAN). The morphology and the functional groups attached herewith the biosorbents before and after adsorption were confirmed by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses. The adsorption isotherms for the two different biosorbent systems were studied in association with Langmuir, Temkin and Freundlich adsorption isotherms using MATLAB software. The monolayer adsorption capacities of RB dye onto chitosan/PVA and chitosan/PAN were found to be 44.39 and 42.4 mg/g respectively. The adsorbed dye molecules were desorbed from chitosan/PVA and chitosan/PAN using HCl solution; thereby regenerating the biosorbents for furthermore adsorption. Copyright © 2018 Inderscience Enterprises Ltd.