Development of Ultrafiltration Reactive Electrochemical Membranes for Contaminant Removal and Fouling Regeneration

The most significant issue affecting the utility of membrane filtration for water treatment is associated with membrane fouling.  Membrane fouling is caused by particulate matter clogging pores, dissolved natural organic matter (NOM) adsorbing to the membrane surface, and biological growth causing biofilm formation.  These various modes of membrane fouling can result in significant flux decline and the need for periodic off-line cleaning procedures. Physical and chemical cleaning procedures are necessary to maintain membrane performance, but result in increased costs associated with operation and disposal of spent chemical reagents.  In this talk we will discuss our ongoing work focused on the development of novel reactive electrochemical membranes (REM) for water treatment applications. These membranes are synthesized from Ti₄O₇ materials and their high conductivity and ability to generate hydroxyl radicals via water oxidation allow them to be used for both contaminant removal and fouling regeneration.  Model membrane foulants (polystyrene beads and NOM surrogates) were used as probes for elucidating the mechanisms associated with membrane fouling and the regeneration of membrane foulants at the REM surface. A new characterization technique based on electrochemical impedance spectroscopy for characterizing fouling at the REM surface will be discussed.