Effect of various sonication modes on permeation flux in cross flow ultrafiltration membrane

• Effect of four sonication irradiation modes were studied on ultrafiltration process.
• Interactions of ultrasound irradiation modes and US frequencies waves were studied.
• Creating alternative mode by power intensity changings was more effective than frequency.
• We have decreased fouling percentage to 10% by ultrasound assisted during 30 min.
• The best condition for ultrasound assisted ultrafiltration were introduced.

The effects of different sonication modes with different frequencies of ultrasound on permeation flux and fouling of ultrafiltration membrane were investigated. The flat sheet membranes in cross flow ultrafiltration were irradiated using various frequencies (37, 80 KHz and tandem) in different sonication modes (continuous, pulsed, sweeping, and degassing). The results showed that the permeation flux was increased with decreasing of ultrasound frequencies. Among applied irradiation modes, the pulsed mode had the most effect on enhancement of permeation flux and reduction of fouling percentage and fouling ratio factor. Creating alternative mode by power intensity changings was more effective than frequency changings. In best condition of filtration, 37 KHz and pulsed mode, the fouling percentage and sonication effect factor (SEF), were 10.53, and 187.4%, respectively. Also permeation flux of pure water confirmed the ultrasonic assisted separation method had no destructive effects on membrane.