Alumosilicate ceramics based composite microalloyed by Sn: An interaction with ionic and colloidal forms of Mn in synthetic water Original Research Article

This paper presents a procedure for the removal of manganese in ionic (Mn2+) and colloidal (MnO2) forms from synthetic waters, by reduction and adsorption processes on electrochemically active alumosilicate ceramics based composite material. Synthesis procedure of the composite material consists of two phases. Firstly, composite particles were synthesized by applying Al/Sn oxide coating on the bentonite particles in an aqueous suspension. In the second phase, aluminum powder was added to the previously obtained plastic mass and after shaping in the form of spheres 1 cm in diameter and drying, sintering was performed at 900 °C. Elemental tin, resulting from the reduction of Sn2+ ion, comes into contact with liquid aluminum in the pores of the matrix performing aluminum microalloying and activation. Moreover, due to a low partial pressure of oxygen, nonstoichiometric oxides with metal excess are obtained, and they play an important role in the electrochemical activity of composite material. In accordance with this, a redox potential of water is changed in contact with composite. The detailed characterization of the composite was carried out by SEM, FTIR and XRD techniques and the influence of pH values on the removal of ionic form of manganese from water was investigated as well.