Use of grape vine bark as an effective biosorbent for the removal of heavy metals (copper and lead) from aqueous solutions

Removal of copper and lead from aqueous solutions was carried out by adsorption on unmodified grape vine bark (GVB). Effect of different parameters such as pH, contact time, biosorbent dose and initial metal ion concentration for the removal of metal ions was investigated. Freundlich isotherm was found to best fit the equilibrium data with correlation coefficients (R-2) which was 0.913 for Cu2+ and 0.984 for Pb2+. The sorption capacity of GVB obtained was 91 mg/g for Pb2+ and 43 mg/g for Cu2+. Kinetic studies showed that adsorption kinetics of copper and lead ions on GVB was best represented by pseudo-second order rate kinetics. Hence, GVB proved a better biosorbent for the removal of copper and lead when compared with many other conventional biosorbents. The analysis of variance of experimental data showed that the sorption capacity is dependent on pH and biosorbent dose.