MBR的在线超声清洗效果及对混合液性质的影响

Effects of Online Ultrasonic Cleaning on Fouling Control and Mixed Liquor Properties in Membrane Bioreactor

将超声波用于膜生物反应器(MBR)的在线清洗,考察了对膜污染的控制效果以及在线超声清洗对混合液性质的影响。结果表明,在线超声清洗对膜污染具有良好的控制效果,但会引起污泥总活性降低,平均污泥粒径减小,过滤性能变差;超声空化作用对硝化活性的影响要比对有机物分解活性的影响大;超声功率和超声时间对混合液的性质影响较大,超声功率越大或超声时间越长则对混合液性质的影响越显著。为避免混合液的性质过度恶化,在线超声清洗的功率不宜过大,每次清洗的时间以5 min左右为宜。

Online ultrasonic cleaning was used for membrane fouling control in membrane bioreactor（MBR）.The effects of online ultrasonic cleaning on membrane fouling control and mixed liquor properties were investigated.The results show that the membrane fouling can be alleviated by online ultrasonic cleaning,but the sludge activity is decreased,the average particle size of the sludge is lowered,and the permeability of mixed liquor gets worse.Ultrasonic cavitation has more influence on nitrification activity than on organic decomposition activity.Ultrasonic power and time are the main factors that influence the mixed liquor properties. The higher the ultrasonic power or the longer the time is,the more remarkable the influence on the mixed liquor properties is.In order to avoid worse properties of mixed liquor,the lower ultrasonic power and shorter cleaning time such as 5 minutes should be applied.