Adsorption of Reactive Black 5 from aqueous solution by cross-linked chitosan/oil palm ash composite beads

Abstract

Adsorption of Reactive Black 5 (RB5) onto cross-linked chitosan/oil palm ash composite beads was studied in batch mode operation with respect to temperature and initial dye concentration. The adsorption of RB5 onto cross-linked chitosan/oil palm ash composite beads increased with increasing temperature (30-50 °C) and initial dye concentration (50 - 500 mg/L). The Langmuir and Freundlich isotherms models were used to described the isotherm data, however, both model Langmuir and Freudlich described the isotherm data with high correlation coefficients. The monolayer coverage capacities of cross-linked chitosan/oil palm ash composite beads of RB5 dyes was obtained 357.1, 344.8 and 303.0 mg/g at temperature 30, 40 and 50°C, respectively. It was observed that the reactive black 5 dye adsorption capacity of cross-linked chitosan/oil palm ash composite beads decreased in the order 30 > 40 > 50°C. The pseudo-first-order and pseudo-second-order were applied to the experimental data and it was found that results of correlation coefficients show the adsorption kinetics obeys a pseudo-first-order model.