Chen Dong, Weavers Linda K, Walker Harold W
Department of Civil and Environmental Engineering and Geodetic Science, The Ohio State University, Columbus, OH 43210, USA.
Water Res. 2006 Feb;40(4):840-50. doi: 10.1016/j.watres.2005.12.031. Epub 2006 Jan 26.
In this study, the effect of particle characteristics on the ultrasonic control of membrane fouling was investigated. Ultrasound at 20 kHz was applied to a cross-flow filtration system with gamma-alumina membranes in the presence of colloidal silica particles. Experimental results indicated that particle concentration affected the ability of ultrasound to control membrane fouling, with less effective control of fouling at higher particle concentrations. Measurements of sound wave intensity and images of the cavitation region indicated that particles induced additional cavitation bubbles near the ultrasonic source, which resulted in less turbulence reaching the membrane surface and subsequently less effective control of fouling. When silica particles were modified to be hydrophobic, greater inducement of cavitation bubbles near the ultrasonic source occurred for a fixed concentration, also resulting in less effective control of fouling. Particle size influenced the cleaning ability of ultrasound, with better permeate recovery observed with larger particles. Particle size did not affect sound wave intensity, suggesting that the more effective control of fouling by large particles was due to greater lift and cross-flow drag forces on larger particles compared to smaller particles.
在本研究中，研究了颗粒特性对膜污染超声控制的影响。在存在胶体二氧化硅颗粒的情况下，将20kHz的超声应用于带有γ-氧化铝膜的错流过滤系统。实验结果表明，颗粒浓度影响超声控制膜污染的能力，在较高颗粒浓度下对污染的控制效果较差。声波强度测量和空化区域图像表明，颗粒在超声源附近诱导了额外的空化气泡，这导致到达膜表面的湍流减少，从而对污染的控制效果降低。当二氧化硅颗粒被改性为疏水性时，在固定浓度下超声源附近空化气泡的诱导作用更强，这也导致对污染的控制效果降低。颗粒尺寸影响超声的清洗能力，较大颗粒的渗透通量恢复效果更好。颗粒尺寸不影响声波强度，这表明大颗粒对污染的控制效果更好是由于与小颗粒相比，大颗粒上的升力和错流阻力更大。
