Journal of Environmental Protection, 2014, 5, 1451-1465 Published Online November 2014 in SciRes. http://www.scirp.org/journal/jep http://dx.doi.org/10.4236/jep.2014.515138 How to cite this paper: Ogunleye, O.O., Ajala, M.A. and Agarry, S.E. (2014) Evaluation of Biosorptive Capacity of Banana (Musa paradisiaca) Stalk for Lead(II) Removal from Aqueous Solution. Journal of Environmental Protection, 5, 1451-1465. http://dx.doi.org/10.4236/jep.2014.515138 Evaluation of Biosorptive Capacity of Banana (Musa paradisiaca) Stalk for Lead(II) Removal from Aqueous Solution Oladipupo O. Ogunleye * , Mary A. Ajala, Samuel E. Agarry Department of Chemical Engineering, Ladoke Akintola University of Technology, Ogbomoso, Nigeria Email: * ooogunleye@yahoo.com Received 27 August 2014; revised 21 September 2014; accepted 11 October 2014 Copyright © 2014 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Raw Banana Stalk (RBS), Acid Activated Banana Stalk (AABS) and Base Activated Banana Stalk (BABS) prepared from banana stalk were used as biosorbents to remove Lead(II) from aqueous solution. The biosorbents were characterised using proximate analysis and Fourier Transform Infrared (FTIR) spectroscopy. Pb(II) of 1000 mg/L concentration was prepared from Pb(NO 3 ) 2 salt and other concentrations were obtained from this stock through serial dilution. Effects of adsor- bent dose, temperature, initial metal concentration, contact time and pH on the percentage Pb(II) removal were evaluated. The Pb(II) concentrations in the solutions were analysed using Atomic Absorption Spectrophotometer. Kinetic, isotherm and thermodynamic parameters were deter- mined. FTIR spectroscopy showed that RBS, AABS and BABS are rich in carboxyl, hydroxyl and phenolic functional groups. At an equilibrium time of 180 minutes, the percentage Pb(II) removal was 63.97%, 96.13% and 66.90% for RBS, AABS and BABS, respectively. Pseudo-second order ki- netics best described the process with R 2 (0.95, 0.98, 0.97) for RBS, AABS and BABS, respectively. Langmuir isotherm (AABS) has the maximum adsorption capacity (q max ) of 13.53 mg/g and R 2 (0.99). Thermodynamic parameters obtained were 0 G ∆ (−18.75 kJ/mol), 0 H ∆ (12.63 kJ/mol), 0 S ∆ (0.05 kJ/mol·K) and a E (4.37 kJ/mol). Banana stalk has viable characteristics for preparing biosorbents. Acid activated banana biosorbent is more efficient for removal of lead ions from its aqueous solution. Keywords Biosorption, Isotherm, Banana Stalk, Kinetics, Lead(II) * Corresponding author.