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 surface materials. 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.Anticipated Results/Potential Commercial Applications as described by the awardee:The membrane concepts to be developed in this study increase the efficiency of commercial filtration processes by increasing system flux and selectivity and reducing downtime to clean or change filters. Because several of these approaches involve simple additions to existing systems, these gains can be achieved very economically.
