Removal of Pb2+ ions by raw corn silk (Zea mays L.) as a novel biosorbent

There is no data about the corn silk usage as adsorbent for lead removal. In the present study, the corn silk (CS), without any modification, was investigated for adsorption of Pb2+ ions from aqueous solutions. The CS before and after Pb2+ adsorption was characterized by SEM-EDX and ATR-FTIR. The effect of pH, contact time, CS dosage and initial metal concentration on process of adsorption was investigated using batch adsorption procedure. The experimental data were fitted to Langmuir and Freundlich isotherm models, and the best data fit was achieved with the Freundlich isotherm model. Also the Langmuir and Freundlich isotherm models constants R-L and n suggesting favorable adsorption of Pb2+ on the CS. Not only the ion -exchange mechanism was confirmed as an adsorption mechanism but the complexation process has also been verified according to results from ATR-FTIR spectra. Thermodynamic parameters were investigated too. Based on desorption study result, the adsorbent can be efficiently recovered. The present investigation qualified the corn silk (Zea mays L.) as a possible good adsorbent of lead from aqueous solutions. (C) 2015 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.