Adsorption of a model anionic dye, eosin Y, from aqueous solution by chitosan hydrobeads

The process of sorption is being increasingly used for ecofriendly and economic remediation of textile dye effluents. The present model study deals with the adsorption of a model anionic dye, eosin Y, from wastewater using conditioned chitosan hydrobeads. Conditioning reduced the pH sensitivity and maintained the maximum sorption capacity of the beads near pH 8. To understand the chemicophysical characteristics of the adsorption process we studied, the kinetics and isotherm behavior of the system. It was observed that temperature played a significant role in the process. The Langmuir model was found to be most appropriate for the description of the adsorption process. The kinetic results followed a second-order equation. It was observed that I g of chitosan adsorbed similar to 76 mg of eosin Y. The dye was desorbed from the beads by changing the pH of the solution, and the conditioned chitosan beads were reused five times without any loss of mechanical and chemical efficacy. (c) 2005 Elsevier Inc. All rights reserved.