Cu(II) adsorption onto Platanus orientalis leaf powder: kinetic, isotherm, and thermodynamic studies

In this study, as a low-cost bio-sorbent prepared from agricultural waste, Platanus orientalis leaf powder (POLP) was used for the removal of Cu(II) ions from aqueous solutions. Morphology of the adsorbent surface and the nature of the possible POLP and Cu(II) interactions were examined by SEM micrograph and FTIR technique, respectively. The influence of various operating parameters such as temperature, pH, contact time, and initial concentration of Cu(II) ions on the leaf powder adsorption capacity was investigated. The adsorption was investigated using different isotherms and kinetic models. The results showed that the adsorption isotherm data were fitted well to the Langmuir isotherm and adsorption kinetics followed the pseudo-second-order model. The thermodynamic parameters, such as ΔG°, ΔH°, and ΔS°, were also evaluated. The calculated parameters indicated that the adsorption process was spontaneous and endothermic in nature. The adsorption capacity of Cu(II) onto POLP was found to be as high as 49.94 mg g−1, which is higher than the adsorption capacity of many recently studied potential adsorbents.