Adsorptive Removal of Cr(VI) and Al(III) From Aqueous Solution by Sugarcane Biomass

Abstract

The potential and effectiveness of activated carbon derived from carbonization of sugarcane bagasse (Saccarhum officianrum) for adsorptive removal of Cr(VI) and Al(III) was examined by adsorption technique. Activated carbon was prepared by subjecting the raw sugarcane bagasse to chemical modification using concentrated sulphuric acid in (1:2) (w/v) of ratio of adsorbent weight to volume of concentrated sulphuric acid (H2 SO4 ). Boehm method was used to estimate the oxygen containing functional groups. The acidic functional groups, specific surface area and adsorptive capacity all greatly increased with chemical modification. The batch removal of Cr(VI) and Al(III) from aqueous solution was investigated. The influence of pH, initial concentration of metal ion and contact time were also investigated. The maximum adsorption capacity of Cr(VI) was found to be 131.68 mg/g at optimum pH of 1 and the maximum adsorption capacity of Al(III) was found to be 125.89 mg/g at optimum pH of 6 at the laboratory temperature respectively. The equilibrium time for Cr(VI) and Al(III) were found to be 180 and 120 minutes respectively. Kinetics of adsorption was found to follow pseudo-second order model. Both Langmuir and Freundlich adsorption isotherm could be used to describe adsorption isotherm but the Langmuir isotherm was found to be in good agreement with experimental data.