ADSORPTION OF TEXTILE DYE FROM AQUEOUS SOLUTION ONTO CHITOSAN COATED PERLITE BEADS

Abstract

Chitosan coated perlite beads were prepared by drop wise addition of gel containing chitosan and perlite into a precipitation bath. The structure of the beads was characterized using Fourier transform infrared spectroscopy (FTIR). The surface area and microstructure of the beads were measured by BET (Brunauer, Emmett and Teller) instrument. The beads that contained chitosan enhanced the accessibility of OH and amine groups for adsorption process. Adsorption of Ostazin Blackdye from aqueous solution on chitosan coated perlite beads was studied using batch adsorption technique and all parameters influencing the removal efficiency such as amount of adsorbent, pH, temperature and initial dye concentration were investigated. Adsorption of Ostazin Black ions reached equilibrium concentration in 48 hours. Experimental data were also evaluated in terms of kinetic characteristics of adsorption and it was found that adsorption process followed well pseudosecond- order kinetics. Langmuirand Freundlich isotherms were studied for the adsorption data over a concentration range of 20 to 80 mg/L. Finally, the thermodynamic parameters including, the change of free energy (AG°), enthalpy (AH®) and entropy (AS°) of adsorption were calculated. The results showed that the adsorption of dye ions on chitosan coated perlite beads was feasible at 25-55°C.