Incorporation of ultrasonic cell disintegration into a membrane bioreactor for zero sludge production

• Published in: Process biochemistry (1991) Vol. 39; no. 12; pp. 1923 - 1929
• Main Authors: Yoon, Seong-Hoon, Kim, Hyung-Soo, Lee, Sangho
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 29.10.2004
• Subjects: Biological treatment; Excess sludge; MBR; Phosphorus removal; Ultrasound; Excess sludge; Phosphorus removal; Biological treatment; MBR; Ultrasound
• ISSN: 1359-5113; 1873-3298
• DOI: 10.1016/j.procbio.2003.09.023

For the prevention of excess sludge production from a membrane bioreactor (MBR), an ultrasonic cell disintegration process was incorporated. The results of this study showed that excess sludge production could be prevented using an ultrasound hybrid (MBR-US) system at an organic loading of around 0.91 kg BOD 5/m 3 per day. Under the same organic loading rate, the mixed liquor suspended solid (MLSS) of MBR-US system was maintained at 7000–8000 mg/l while the MLSS of a conventional MBR increased from 7000 to 13,700 mg/l during the experimental period. While sludge production was completely prevented, the effluent quality of the MBR-US system slightly deteriorated. The additional organic loading caused by disintegrated sludge return was considered to be a reason. With sonication the volume of the average particle size of the sludge in the aeration tank decreased from 132 to 95 μm. In the MBR-US system, around 25–30% of total phosphorus removal was achieved without sludge removal from the aeration tank.