Biosorption of Mn(II) ions from water solutions by natural sorbent: equilibrium study

In the modern society, the problem of the treatment of natural and wastewater resources and their management, is becoming very important. Of particular interest is the definition of adequate and sophisticated procedures for the treatment of natural and wastewater resources, regardless of whether the source of pollution is of geogenic or anthropogenic origin. Sustainable development of separation processes has recently been increasingly imposed by the need to develop modern, non-conventional bioseparation processes for the elimination of toxic metals from wastewater, by applying low cost unconventional sorbents. The purpose of this paper is to remove Mn (II) ions from aqueous solutions by applying a natural adsorbent (grape branches - agricultural waste). To accomplish the established goal, the experiments were carried out with model solutions with known initial concentrations of Mn(II) ions in a laboratory batch reactor, with the purpose of studying the effect of adsorption time on adsorbate concentration and on the adsorbed amount of Mn(II) ions. The raw material was characterized in terms of its chemical composition and particle size distribution. The obtained results were applied to model the adsorption equilibrium using several adsorption isotherms such as Langmuir, Freundlich, Langmuir-Freundlich and Redlich-Peterson, using the MATLAB/Curve fitting toolbox software package.