Valorisation of energy plant Arundo donax cultivated in Serbia for biosorption of cobalt ions from an aqueous solution: Kinetic aspect

Abstract

Metal ions can be eliminated from aqueous solutions using biosorbent, a substance made from plant biomass. This study investigated the potential use of Arundo donax stems as a cheap, natural biosorbent to remove cobalt ions (Co2+) from an aqueous solution. The biosorbent was characterized by the chemical composition analysis (cellulose, hemicellulose, and lignin), the point of zero charge (pHPZC), by scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction analysis, and Fourier-transform infrared spectroscopy. According to the experimental data of kinetic studies, the equilibrium condition of Co2+ adsorption was attained 360 min after the biosorption started. The pseudo-first, pseudo-second, Elovich, and intra-particle diffusion models were used to model the kinetic experimental data. The best compliance was obtained with the pseudo-first order kinetic model, considering the highest value of the coefficient of determination R2 (0.996) and the lowest chi-square (2) value (0.757). The findings of this study can be applied to the design of batch biosorption systems for the removal of Co2+ ions in real industrial systems.

Keywords

• biosorbent
• co2+ removal
• kinetic modeling