Adsorption kinetics of sugarcane bagasse for selective removal of Cr (VI) and Cu (II) from aqueous solutions

Abstract

.The Adsorption Kinetics for the simultaneous and selective removal ofCr(VI) and Cu(II) ions fromaqueous mixture was investigated using sugarcane bagasse. Equal volumes of the laboratory preparedmetal ion solutions ofCr(VI) and that ofCu(II), having the same initial concentration were mixed andused as test samples. Batch studies were performed at room temperature at three different initialconcentrations of each metal ion to be present in the test sample: 10ppm, 30ppm and 50ppm. Theavailable literature for the removal of each of these heavy metal ions when present individually inaqueous solutions was applied in these studies. Accordingly, water washed and sun dried sugarcanebagasse retained on 200 micron-mesh, was used for the study at a dosage of OAg/l of the test sample.No attempt was made to maintain a fixed pH as this involved addition of more chemicals adding tomore contamination. Instead, the pH and remaining concentrations of the ions in the mixture afteradsorption were monitored at various pre-set time intervals till equilibrium condition was attained. ThepH of the test samples varied from 7.05 initial values to 8.09 at equilibrium, during all the batchstudies. The study has revealed that the adsorbent had higher selectivity to Cu(II) ions in comparisonto the Cr(VI) ions at the study conditions. The removal was faster and higher at low initialconcentrations. The experimental results fit well with linearized Freundlich Adsorption Isotherm Model.