Activated carbons produced by pyrolysis of waste potato peels: Cobalt ions removal by adsorption

This study investigates the use of activated carbons after pyrolysis of waste potato peels for the removal of cobalt ions from synthetic wastewaters (composed of various Co(II) concentrations in distilled water which adjusted previously at different pH values) without any co-existing ions. The activation agent was phosphoric acid, while three different carbons were prepared based on the different activation temperatures (400, 600, 800 degrees C). Characterization techniques used for the study of surface chemistry of carbons prepared (Boehm and potentiometric titrations, BET analysis, SEM/EDAX, DTG), while the possible adsorption mechanism between carbons and Co2+ was further investigated using FTIR spectroscopy. Equilibrium and kinetic experiments were carried out at the optimum pH (6). Free energy, enthalpy, and entropy were also evaluated. (C) 2015 Elsevier B.V. All rights reserved.