Chemical analysis of corn cob-based biochar and its role as water decontaminants

Abstract

Production of biochar is accomplished by pyrolysis of corncobs at 350 °C (BC-350) and 450 °C (BC-450) under oxygen-limited conditions. The chemical and physical properties were investigated via XRD, FTIR, BET, SEM and EDX analysis. Batch experiments were conducted for the adsorption of Pb2+ ions from aqueous solution onto biochar with regards to pH, contact time, biochar dose and initial Pb2+ concentration. The adsorption efficiency of Pb2+ was increased as increasing pH and biochar dose up to 1.5 g/L. Kinetic and isothermal studies demonstrated that the experimental data were fitted with the pseudo-second-order model, Langmuir and Freundlich isotherms. The study emphasized the preferable pyrolysis temperature which is 450 °C. According to the Dubinin-Kaganer-Radushkevich (DKR) model, the adsorption process of Pb2+ was a chemical and endothermic reaction. Results showed the applicability of corncob based biochar to be used as an efficient and low cost adsorbent for Pb2+ ions removal.