Preparation, characterization of raw corncob adsorbent for removal of heavy metal ions from aqueous solution using batch method

Abstract

Corncob adsorbent was prepared through environmental friendly process without any additional chemical treatment. The prepared material was characterized by X-ray diffract meter (XRD), Fourier transform infrared spectroscopy (FTIR) and pH points zero charge techniques. The XRD diffracted pattern of corncob adsorbent did not shows well-defined sharp peaks instead it shows pumps peaks; this indicates that the diffraction patterns of the corncob adsorbent has low crystallinity (amorphous). FTIR characterizations of corncob indicate the presence of functional groups. The point zero charge of corncob adsorbent was found to be 7.05; it can be basic modification of the adsorbate which gave a negative (basic) surface charge for the adsorbent. The effect of corncob dosage, contact time and solution pH were studied at optimum values for removal of Pb, Cd, Cr and Cu metals using Batch method. Adsorption equilibrium data fitted well with the Freundlich isotherm for Pb, Cd and Cu metal ions but Langmuir isotherm for Cr(VI) metal ion. Key words: Adsorption equilibrium, batch method, corncob, metal ions, optimum values.