Development of an adsorbent via chitosan nano-organoclay assembly to remove hexavalent chromium from wastewater

This study involves nano-biocomposite (chitosan-nanoclay composite, CNC) preparation using solvent casting method with chitosan and organoclay (Cloisite 20A) and investigation of Cr6+ ion adsorption. The influence of contact time, solution pH, initial metal concentration, concentration of the adsorbents and temperature on the removal of Cr6+ ions were examined. Langmuir, Freundlich and Scatchard adsorption isotherms were tested. Maximum adsorption capacity of 128.43 mg of Cr6+/g for CNC and 21.83 mg of Cr6+/g for chitosan were obtained according to the Scatchard adsorption isotherm at pH of 2 and 3, respectively. Obtained results showed that the adsorption data for Cr6+ ions on CNC correlated well with the Langmuir isotherm model. (C) 2016 Elsevier B.V. All rights reserved.