Characteristics Of The Membrane - The Biological Reactor Ultrasonic Cleaning

For effective control of membrane fouling commonly occurred in the conventional membrane bioreactor (MBR), an ultrasonic-membrane bioreactor (UMBR) was proposed in this dissertation. In the novel process, online ultrasonic cleaning was used for membrane bioreactor. First, optimum parameters of the ultrasonic-membrane bioreactor were confirmed by a short-term experiment. Then effect of online ultrasonic cleaning and changes of the mixed-liquid under the ultrasonic radiation were studied.In the short-term experiment, characteristics of the mixed-liquid were deteriorated for cavitations of ultrasonic. It's bad for the control of membrane fouling. Main factors that cause characteristics of the mixed-liquid were deteriorated were ultrasonic power and lasted time. To avoid excessive deterioration of the mixed-liquid and save energy consumption, ultrasonic power and lasted time should be controlled. Optimum parameters of the ultrasonic-membrane bioreactor were: ultrasonic power is 300W and lasted time is 3~5min.In the long-term experiment, when ultrasonic power is 300W and lasted time is 5min, characteristics of the mixed-liquid were not deteriorated. In terms of quality of the effluent, the ultrasonic-membrane bioreactor was similar to conventional membrane bioreactor. When ultrasonic power is 300W and lasted time is 5min and interval between two cleanings is 12h, under the same operational conditions, TMP of the ultrasonic-membrane bioreactor was approximately lower 10kPa, after 25 days operation, than conventional membrane bioreactor for contrast. After operation for periods, effect of the ultrasonic was declined for weakening of concentration polarization.