Biosorption potential of the waste biomaterial obtained from Cucumis melo for the removal of Pb2+ ions from aqueous media: Equilibrium, kinetic, thermodynamic and mechanism analysis

Abstract The potential use of a waste biosorbent material obtained from Cucumis melo ( C. melo ) for the removal of Pb 2+ ions from aqueous solutions was investigated by considering equilibrium and kinetic aspects. The biosorption showed a pH dependent profile. An increase in biosorbent dosage up to 1.8 g L −1 caused an increase in the biosorption yield of the biosorbent. The relatively fast biosorption at all studied temperatures follows the pseudo-second-order kinetic model. Biosorption isotherm modeling shows the equilibrium data fitted to the Langmuir model with a maximum monolayer biosorption capacity of 3.64 × 10 −4  mol g −1 . The thermodynamic parameters indicated the biosorption of Pb 2+ on the biomass was a spontaneous and endothermic process. Experiments conducted with multi-metal system demonstrated that the presence of co-ions slightly reduced the Pb 2+ biosorption capacity of the biomass. The possible Pb 2+ ion-biomaterial interactions were evaluated by the zeta potential, FTIR, SEM and EDX analysis. Results of this work showed the suggested biosorbent could be an effective and eco-friendly alternative for the removal of Pb 2+ ions from contaminated solutions.