Optimal condition for modification of chitosan: A biopolymer for coagulation of colloidal particles

Chitosan, an acetylated derivative of chitin, is a biodegradable cationic p olymer. Chitosan can be a promising substitute for alum in the coagulation process, because of its potential feasibility in coagulation without posing any health threat as the residual aluminium and other synthetic polymers d o. In this study, various pretreatment conditions were tested in search of the optimum chitosan modification. Batch tests with synthetic source water suggest that the optimal pretreatment condition to prepare modified chitosa n coagulant is deacetylation by 45% alkali solution for 60 min, followed by dissolution in 0.1% hydrochloric acid. (C) 2000 Elsevier Science Ltd. All rights reserved.