Removal of Acid Blue 158 from Aqueous Media by Adsorption Onto Cross-Linked Chitosan Beads

Chitosan bead was cross-linked and chemically modified by means of protonation and carboxylation in order to enhance its sorption capacity. The feasibility of these modified chitosan beads for removing anionic dye namely Acid blue 158 (AB 158) from aqueous solution was investigated. The effects of various experimental parameters (e.g., contact time, sorbent dosage, initial pH, co-ions) were examined and optimal experimental conditions were decided. The sorption capacity (SC) for the removal of AB 158 using cross-linked chitosan beads (CB) and modified chitosan beads such as protonated chitosan beads (PCB) and carbo) carboxylated chitosan beads (CCB) was in the order of PCB > CCB > CB. The modified chitosan beads were characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy. The isothermal data was fitted with Freundlich model. Various thermodynamic parameters such as, standard free energy change (AG), standard enthalpy change (Delta H degrees) and standard entropy change (AS), were calculated which indicated that the system was spontaneous and exothermic process. The sorption kinetics followed the pseudo-second-order and intraparticle diffusion models.