ABSTRACT
Water pollution has become a major problem in the world. This is due to the rapid development and industrialization which have resulted in a huge amount of wastewater being discharged into the water system. Wastewater treatment is crucial to protect our environment, health of mankind, and maintain a balanced ecosystem. The development of a cost-effective and sustainable wastewater treatment method is necessary. Among all, adsorption method is the most used and investigated by researchers. Hydrogel is a threedimensional network structure material that could provide a good pollutant adsorption capacity, good swelling, and reversible swelling property. Chitosan is a biopolymer that produced via the de-acetylation of chitin. It 4is abundantly available, low cost, highly porous, biodegradable, and can be functionalized easily due to hydroxyl and amino functional groups. Chitosan has been widely used as the starting materials to produce chitosan-based adsorbents, such as chitosan-based composite hydrogels, chitosan-based hydrogels beads, copolymeric chitosan-based hydrogels, membranes, and clays. This chapter summarizes the current trend and development of chitosan-based adsorbents for wastewater treatment toward different types of pollutants (heavy metal ions, dye, organic pollutants, etc.). Various modified forms of chitosan-based adsorbents are discussed with particular emphasis on their use toward different types of pollutants in wastewater. This chapter also provides a brief perspective on the potential of chitosanbased adsorbents for wastewater treatment.
