Removal of Pb (II) from aqueous solution by using micro-spheres of Zea mays rachis–sodium alginate by batch and column systems

The behavior of composite beads of Zea mays rachis and sodium alginate (AL) for Pb (II) adsorption was studied. The Zea mays rachis–sodium alginate was prepared and characterized. The IR spectra showed interactions of the functional groups and the metal ions after adsorption. The kinetic data were fitted to the pseudo-first- and pseudo-second-order models, the maximum adsorption capacity was 60 mg/g for Pb (II), and the isotherm data were best adjusted to the Freundlich model, indicating that the adsorbent is heterogeneous. The thermodynamic study shows that the process is physisorption. The service time of columns increases as the height of columns increases, and this behavior was attributed to the active sites available in the columns. The initial concentration of Pb (II) had a significant effect on the breakthrough curves. As the concentration increases, the saturation time decreases. The material was regenerated four times (adsorption–desorption cycles), without a significant change in the removal efficiencies.