ADSORPTION OF L-LYSINE FROM AQUEOUS SOLUTION BY SPHERICAL LIGNIN BEADS: KINETICS AND EQUILIBRIUM STUDIES

Abstract

The potential of spherical lignin beads as an adsorbent to take up L-lysine from aqueous solution was investigated. The kinetic data were estimated by the pseudo-first-order and pseudo-second-order models. The mechanism of adsorption was also studied using the Boyd model and Webber’s intraparticle diffusion model. The equilibrium data were modeled by the Langmuir, Freundlich, and Dubinin-Radushkevich (D-R) isotherms as well. Results suggested that the adsorption kinetics can be best described by the pseudo-first-order model. The adsorption process initially was controlled by film diffusion, whereas the subsequent stage was controlled by intraparticle diffusion. The equilibrium data could be well fitted using the Langmuir isotherm model with a maximum adsorption capacity of 67.11 mg•g-1. The adsorption characteristics of the spherical lignin adsorbent proved the feasibility of its use as an alternative adsorbent for the removal of L-lysine from aqueous solution.

Keywords

• Spherical lignin
• Adsorption
• L-lysin
• Kinetic