Application of chitosan, a natural aminopolysaccharide, for dye removal from aqueous solutions by adsorption processes using batch studies: A review of recent literature

Application of chitinous products in wastewater treatment has received considerable attention in recent years in the literature. In particular, the development of chitosan-based materials as useful adsorbent polymeric matrices is an expanding field in the area of adsorption science. This review highlights some of the notable examples in the use of chitosan and its grafted and crosslinked derivatives for dye removal from aqueous solutions. It summarizes the key advances and results that have been obtained in their decolorizing application as biosorbents. The review provides a summary of recent information obtained using batch studies and deals with the various adsorption mechanisms involved. The effects of parameters such as the chitosan characteristics, the process variables, the chemistry of the dye and the solution conditions used in batch studies on the biosorption capacity and kinetics are presented and discussed. The review also summarizes and attempts to compare the equilibrium and kinetic models, and the thermodynamic studies reported for biosorption onto chitosan. (C) 2007 Elsevier Ltd. All rights reserved.