Basic Dye Adsorption on Low Cost Biopolymer: Kinetic And Equilibrium Studies

Abstract

The adsorption behavior of crystal violet, on chitosan has been studied extensively. A series of experiments were conducted in a batch system to evaluate the effect of the system variables .i.e. initial pH, initial dye concentration, contact time and temperature. The adsorption facts were analyzed by using Langmuir, Freundlich, Temkin and Dubinin-Radushkveich isotherm models. The equilibrium data were best represented by Langmuir isotherm model showing maximum monolayer adsorption capacity 28.5 mg/g. The kinetic data were fitted to pseudo-second order kinetic model which shows that intraparticle diffusion has a significant role in the adsorption process. The thermodynamics of crystal violet onto chitosan indicate its spontaneous and endothermic nature. The adsorbent was analyzed by N 2 adsorption-desorption technique, FTIR, SEM, and TG-DTG. Chitosan was shown to be promising adsorbent for the removal of dyes from aqueous solutions.