Effects of chemical sludge disintegration on the performances of wastewater treatment by membrane bioreactor

• Published in: Water research (Oxford) Vol. 41; no. 12; pp. 2665 - 2671
• Main Authors: Oh, Young-Khee, Lee, Ki-Ryong, Ko, Kwang-Baik, Yeom, Ick-Tae
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.06.2007; Elsevier Science
• Subjects: Applied sciences; Bioreactors; Chemical sludge treatment; Exact sciences and technology; Hydrogen-Ion Concentration; Membrane bioreactor (MBR); Membranes, Artificial; Other industrial wastes. Sewage sludge; Ozone - chemistry; Pollution; Sewage; Sludge disintegration; Sodium Hydroxide - chemistry; Waste Disposal, Fluid - methods; Wastes; Water treatment and pollution; Membrane bioreactor (MBR); Sludge disintegration; Chemical sludge treatment; Membrane reactor; Membrane bioreactor (MBR) Chemical sludge treatment Sludge disintegration; Bioreactor; Sludge excess; Chemical treatment; Water quality; Ozone; Waste water purification; Biological purification
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2007.02.028

A new wastewater treatment process combining a membrane bioreactor (MBR) with chemical sludge disintegration was tested in bench scale experiments. In particular, the effects of the disintegration treatment on the excess sludge production in MBR were investigated. Two MBRs were operated. In one reactor, a part of the mixed liquor was treated with NaOH and ozone gas consecutively and was returned to the bioreactor. The flow rate of the sludge disintegration stream was 1.5% of the influent flow rate. During the 200 days of operation, the MLSS level in the bioreactor with the disintegration treatment was maintained relatively constant at the range of 10,000–11,000 mg/L while it increased steadily up to 25,000 mg/L in the absence of the treatment. In the MBR with the sludge disintegration, relatively constant transmembrane pressures (TMPs) could be maintained for more than 6 months while the MBR without disintegration showed an abrupt increase of TMP in the later phase of the operation. In conclusion, a complete control of excess sludge production in the membrane-coupled bioreactor was possible without significant deterioration of the treated water quality and membrane performances.