title: Ultrasonic control of ceramic membrane fouling by particles: effect of ultrasonic factors.
abstract: Ultrasound at 20 kHz was applied to a cross-flow ultrafiltration system with gamma-alumina membranes in the presence of colloidal silica particles to systematically investigate how ultrasonic factors affect membrane cleaning. Based on imaging of the ultrasonic cavitation region, optimal cleaning occurred when the membrane was outside but close to the cavitation region. Increasing the filtration pressure increased the compressive forces driving cavitation collapse and resulted in fewer cavitation bubbles absorbing and scattering sound waves and increasing sound wave penetration. However, an increased filtration pressure also resulted in greater permeation drag, and subsequently less improvement in permeate flux compared to low filtration pressure. Finally, pulsed ultrasound with short pulse intervals resulted in permeate flux improvement close to that of continuous sonication.
authors.affiliation: Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University, 470 Hitchcock Hall, 2070 Neil Ave., Columbus, OH 43210, USA.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.forename: Linda K
authors.initials: LK
authors.lastname: Weavers
authors.forename: Harold W
authors.initials: HW
authors.lastname: Walker
mesh_terms: D002516:Ceramics / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D004867:Equipment Design; D008566:Membranes / Q000737:chemistry; D008567:Membranes, Artificial; D011312:Pressure; D013010:Sonication; D014462:Ultrafiltration / Q000295:instrumentation* / Q000379:methods; D014465:Ultrasonics; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D003102:Colloids; D008567:Membranes, Artificial