Dyes adsorption from aqueous solutions by Chitosan

In this study the ability of chitosan to remove acid, basic, reactive and direct dyestuffs by adsorption was studied. The effect of several factors influencing dye adsorption such as dye concentration, grain size, pH and temperature were investigated. Desorption of dyes at different pH was also examined. It was shown that the adsorption capacities of chitosan were comparatively high for acid and direct dyes and that the adsorption was controlled by the acidity of the solution. The kinetics of adsorption were found to be of pseudo second order. Batch isotherm studies showed that adsorption of dyes from aqueous solution by chitosan was described by the Langmuir equation.