Abstract: The present invention refers to a method for the synthesis of an adsorbing material consisting of a single-phase tetravalent manganese feroxyhite (?-Fe(1-x)MnxOOH), in which a percentage of 0.05 to 25% of iron atoms has been isomorphically substituted by Mn(IV) atoms. Its production takes place in a continuous two-stage flow reactor at weakly acidic conditions (pH 4-7) and high redox (300-800 mV). The material can be used for the removal of both pentavalent and trivalent arsenic as well as other heavy metals form water. More specifically, its adsorption capacity and selectivity depending on the trivalent and pentavalent arsenic water content, are determined by the manganese percentage and the compact or hollow morphology of its structural unit which can be both controlled by the parameters of the synthesis procedure.

Abstract: The present invention refers to a method for the synthesis of an adsorbing material consisting of a single-phase tetravalent manganese feroxyhite (?-Fe(1-x)MnxOOH), in which a percentage of 0.05 to 25% of iron atoms has been isomorphically substituted by Mn(IV) atoms. Its production takes place in a continuous two-stage flow reactor at weakly acidic conditions (pH 4-7) and high redox (300-800 mV). The material can be used for the removal of both pentavalent and trivalent arsenic as well as other heavy metals form water. More specifically, its adsorption capacity and selectivity depending on the trivalent and pentavalent arsenic water content, are determined by the manganese percentage and the compact or hollow morphology of its structural unit which can be both controlled by the parameters of the synthesis procedure.