Adsorption of chromium (VI) from aqueous solution by the iron (III)-impregnated sorbent prepared from sugarcane bagasse

An iron (III)-impregnated sorbent was prepared from sugarcane bagasse and ferric chloride solution via carbonization/activation in a muffle furnace at 500 C for 4 h. The adsorption removal of chromium (VI) from aqueous solution by the iron (III)-impregnated sorbent was then studied in a batch system. With increasing initial chromium (VI) concentration from 25 to 130 mg/L at an adsorbent dose of 300 mg/50 mL, the amount of adsorbed chromium (VI) increased from 4.15 to 12.20 mg/g at 20 C, from 4.16 to 12.50 mg/g at 30 C, and from 4.16 to 13.72 mg/g at 40 C. The dynamical data fit very well with the pseudo-second-order kinetic model, and the calculated adsorption capacities of 4.16, 8.37, and 13.37 mg/g were equal to the actual values of the experiments at the initial chromium (VI) concentrations of 25, 50, and 100 mg/L, respectively. The Langmuir isotherm could yield better fits than the Freundlich isotherm. The calculated isotherm parameters confirmed the favorable adsorption of chromium (VI) on the iron (III)-impregnated sorbent.