ENHANCEMENT OF MEMBRANE FILTER PERFORMANCE BY VIBRATION

SO-CALLED "FOULING" OF FILTRATION MEMBRANES, WHICH LEADS TO DIMINISHED FILTRATE FLUX AND ALTERED SOLUTE REJECTION AND SELECTIVITY WITH TIME, IS ATTRIBUTABLE TO BUILDUP OF SURFACEMATERIALS. RESPONSIBLE MECHANISMS INCLUDE BOUNDARY LAYER, GEL AND CAKE PHENOMENA, AND INTERACTIONS OF PARTICLES OR SOLUBLE COMPONENTS (E.G., PROTEINS) WITH THE MEMBRANE. A POSSIBLE SOLUTION TO THIS PROBLEM IS VIBRATION OF THE MEMBRANE SURFACE TO MINIMIZE AND/OR DISLODGE THIS BUILDUP. TO DEMONSTRATE THE POTENTIAL OF THIS CONCEPT, A SERIES OF LABORATORY EXPERIMENTS ARE TESTING THE ABILITY OF TWO CONFIGURATIONS TO ENHANCE FILTRATE FLUX. ONE CONFIGURATION INVOLVES VIBRATION OF COMMERCIALLY AVAILABLE MEMBRANES, AND THE OTHER IS AN INTRINSICALLY PIEZOELECTRIC MEMBRANE. EFFECTS OF EXCITATION LEVEL, FREQUENCY, AND TEMPORAL CHARACTERISTICS ON FILTER OUTPUT ARE BEING QUANTIFIED IN PHASE I.