ADSORPTION PHENOMENA OF TELON BLUE AGLF: ISOTHERMS, KINETICS AND THERMODYNAMICS OF DYE ADSORPTION ONTO CHITOSAN

摘要

In this study, the ability of chitosan, derived from deacetylated crab shell chitin, to remove Telon Blue AGLF dye from effluent solution by adsorption was investigated. The effects of initial dye concentration, solution pH, solution temperature and sorbent dose on sorption were studied. Maximum dye removal was achieved at pH 4 and 25°C. Furthermore, it was concluded that the amount of dye removed increased with increasing initial dye concentration (from 25 to 150 mgL~(-1)), and sorbent dose (from 0.5 to 4.0 g L~(-1)). Equilibrium isotherms were analysed by Freundlich and Langmuir isotherm equations using correlation coefficients and three error functions. The maximum monolayer capacities (q) of chitosan at pH 4; an adsorbent dosage 1 g L~(-1); and temperatures of 25, 35, and 45°C were determined to be 140.84, 105.26 and 136.98 mg g~(-1), respectively. The results indicate that the Langmuir model provides the best correlation to the experimental data. Three kinetic models-the pseudo-first-order, second-order, intraparticle diffusion models-were used to investigate the adsorption mechanism. The kinetic experimental data agreed very well with the pseudo second-order kinetic model. Moreover, the thermodynamics of adsorption were investigated and the thermodynamic parameters for the dye were evaluated. These parameters revealed that the dye adsorption onto chitosan is a spontaneous, exothermic, and physical reaction. The results showed that chitosan is a suitable as adsorbent material for the adsorption of Telon Blue AGLF dye from aqueous solutions.