Efficient polymers in conjunction with membranes to remove As(V) generated in situ by electrocatalytic oxidation

Electrochemistry and ultrafiltration membrane methods (electro-oxidation and liquid phase polymer based retention technique LPR, respectively) were coupled to remove As(III) inorganic species from aqueous solutions. Our main objective was to achieve an efficient extraction of arsenic species by associating a polymer-assisted liquid phase retention procedure, based on the As(V) adsorption properties of cationic water-soluble polymers, with the electrocatalytic oxidation process of As(III) into its more easily removable analog As(V). The exhaustive oxidation of As(III)-As(V) was readily performed in high yield at iridium oxide film modified carbon felt electrodes in the presence of different water-soluble poly(quaternary ammonium) salts acting also as supporting electrolyte. The progress of the macro-scale oxidation of As(III)-As(V) was followed using iridium oxide film modified glassy carbon electrodes. Finally, a study on arsenic retention by LPR-technique performed on fully oxidized solutions of arsenic, showing that complete (100%) retention of the arsenic could be achieved using a 20: 1 polyammonium: As(III) mole ratio. Copyright (C) 2009 John Wiley & Sons, Ltd.