Abstract
In view of adsorption efficiency of modified agricultural biomasses, present study was conducted to appraise the chromium [Cr(III) and Cr(VI)] adsorption capacities of corn cob immobilized biomass. Corn cob biomass was immobilized in calcium alginate bead and process variables such as Cr ions initial concentrations, pH, dosage and contact time were optimized. The Cr(III) and Cr(VI) were adsorbed up to 277.57 mg/g and 208.6 mg/L onto corn cob immobilized biomass under optimized conditions of process variables. Both Cr ions followed Langmuir isotherm and the pseudo-second order kinetic model. Optimized conditions were employed for Cr adsorption from tannery effluents and up to 64.52% and 55.98% Cr(III) and Cr(VI) were removed, respectively. The immobilized corn cob biomass was run up to 5 repeated adsorption-desorption cycles and 0.98% and 1.51% adsorption efficiencies were reduced at the end of 5 adsorption-desorption cycles of Cr(III) and Cr(VI), respectively. NaOH (0.1 M) efficiently desorbed the Cr ions from corn cob immobilized adsorbent and up to 79.8% and 86.0% Cr(III) and Cr(VI) ions were recovered respectively. Results revealed that the immobilization is a viable technique for the modification of native agricultural biomass for efficient remediation/sequestration of metal ions from industrial effluents. (C) 2017 Brazilian Metallurgical, Materials and Mining Association. Published by Elsevier Editora Ltda.