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.

Fabrication and characterization of a novel TiO2 nanoparticle self-assembly membrane with improved fouling resistance

“…One of the main obstacles in wastewater treatment by membrane separation is membrane fouling [1,2]. Membrane fouling is often caused by irreversible deposition of organics in the feed water on the hydrophobic membrane surface, which will result in water flux loss and solute selectivity change with time [3].…”

Membrane module design and dynamic shear-induced techniques to enhance liquid separation by hollow fiber modules: a review

“…For instance, it has been observed via field emission scanning electron microscopy (FESEM) that some polymeric materials can be restructured by ultrasonic irradiation [110,113,114], such as polyethersulphone (PES), cellulose nitrate with cellulose acetate (CN-CA) or nylon6 (N6); on the other hand Poly Vinylidene Fluoride (PVDF) and Poly Acrylonitrile (PAN) showed no observable damage with long term exposure. Though some work has been done to examine the mechanism of membrane damage by ultrasound [115], caution must be taken to choose proper membrane materials, ultrasonic intensity and irradiation duration to avoid membrane damage.…”

Preparation of Ordered TiO₂ Macroporous Membrane Using PBMA Colloid Crystal as Template

“…Membrane separation technique therefore is playing an important role in wastewater treatment and water reuse due to its efficient without requiring a phase change, continuous operation and little chemical addition required. However, a major obstacle to futher use in water treatment is flux decline resulting from fouling [1] . Several strategies to reduce fouling have therefore been investigated in recent years including the use of TiO 2 membrane coupled with photocatalytic effects [2][3][4] .…”