64 American Scientific Research Journal for Engineering, Technology, and Sciences (ASRJETS) ISSN (Print) 2313-4410, ISSN (Online) 2313-4402 © Global Society of Scientific Research and Researchers http://asrjetsjournal.org/ Adsorption Studies of Cu 2+ from Aqueous Solutions Using Unmodified and Citric Acid – Modified Plantain (Musa paradisiaca) Peels Abiodun Aderibigbe a *, Oluwafemi Ogunlalu b ,Oluwasegun Wahab c , Olugbenga Oluwasina d , Isiaka Amoo e a,b,c,d,e Department of Chemistry, Federal University of Technology Akure, Ondo State, Nigeria a Email: adaderibigbe@futa.edu.ng Abstract Natural plantain peel biomass and the citric-acid-modified form were used to study the adsorption of Cu 2+ from a simulated aqueous solution in a batch adsorption system. The adsorption was strongly pH-dependent as maximum adsorption was recorded at a pH of 5 for the modified biomass and pH of 4 for the unmodified. The kinetics of the adsorption processes was studied with Pseudo-first-order, Pseudo-second-order, Intra-particle diffusion, Elovich and Fractional power kinetic models and the results were best fitted by the pseudo-second- order model. The experimental data were also subjected to Langmuir, Freundlich and Temkin isotherms for adsorption studies and the unmodified biomass was best fitted by the Temkin adsorption isotherm while the modified biomass, on the other hand was best fitted by the Freundlich isotherm. Thermodynamic studies revealed that the heat of adsorption of the unmodified biomass was higher than the modified. The maximum adsorption capacity obtained was 48.31 mg/g. Keywords: Adsorption; citric acid; copper (II); plantain peels. 1. Introduction Heavy metals, which are non-biodegradable substances that can constitute adverse health effects to man and livestock remains one of the main causes of pollution of water bodies. One of these is copper which when inadequately controlled as an industrial effluent has been responsible for notable havocs around the world. ------------------------------------------------------------------------ * Corresponding author. brought to you by CORE View metadata, citation and similar papers at core.ac.uk provided by American Scientific Research Journal for Engineering, Technology, and Sciences...