Arsenic Oxidation by Membrane Contactors

This chapter deals with the potential of membrane contactors for the oxidation of As(III) with air. In particular, experiments carried out on a flat membrane module of 40 cm2 of membrane area, equipped with a polypropylene membrane of 0.2 ?m pore size, are presented and discussed. Oxidation experiments have been also performed without using membranes by: (1) stirring the water stream; (2) introducing air/oxygen into the water stream through a tube; (3) introducing air/oxygen into the water stream through a porous unit. With respect to the different systems analysed, membrane contactors lead to lower mass transport resistances in the liquid phase, significantly reducing the times for oxidation.