Adsorption of Victoria blue by carbon/Ba/alginate beads: Kinetics, thermodynamics and isotherm studies

The kinetic, thermodynamic and isotherm modeling studies were carried out on adsorptive removal of Victoria blue (VB) dye using activated carbon, Ba/alginate and modified carbon/Ba/alginate polymer beads. The feasibility of sorption process was determined by varying the experimental parameters viz., dye concentration (4-20 mg L−1), contact time (10-90 min), pH (3-10), adsorbent dose (0.5-2.5 g) and temperature (303-343 K). Freundlich and Langmuir isotherms were determined and ascertained with the dimensionless separation factor (RL). Lagergren's pseudo-first order, pseudo-second order and intraparticle diffusion model equations were used to analyze the kinetics of the adsorption process. The thermodynamic consistency of adsorption was found with Gibbs free energy (ΔG°), changes in enthalpy (ΔH°) and entropy (ΔS°) were calculated using the Van't Hoff plot. The polymer beads were characterized using Fourier Transform Infrared Spectroscopy (FTIR) and their morphology was determined by scanning electron microscopy (SEM).