Reduction in excess sludge production in a dairy wastewater treatment plant via nozzle-cavitation treatment: Case study of an on-farm wastewater treatment plant

• Published in: Bioresource technology Vol. 100; no. 12; pp. 3161 - 3166
• Main Authors: Hirooka, Kayako, Asano, Ryoki, Yokoyama, Atsushi, Okazaki, Masao, Sakamoto, Akira, Nakai, Yutaka
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2009; [New York, NY]: Elsevier Ltd; Elsevier
• Subjects: activated sludge; Agriculture - methods; Applied sciences; Biological and medical sciences; Bioreactors; Biotechnology; Cavitation nozzle; Computer-Aided Design; Dairy Products; dairy wastes; Dairy wastewater; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; Excess sludge; Food industries; Fundamental and applied biological sciences. Psychology; Industrial Waste - prevention & control; industrial wastes; Membrane bioreactor; Methods. Procedures. Technologies; milking; milking parlors; Pollution; Reproducibility of Results; Sensitivity and Specificity; Sewage - chemistry; Sonication - instrumentation; Use and upgrading of agricultural and food by-products. Biotechnology; Various methods and equipments; Wastes; wastewater treatment; Water Pollution, Chemical - prevention & control; Water Purification - instrumentation; Water Purification - methods; Membrane bioreactor; Excess sludge; Dairy wastewater; Cavitation nozzle; Dairy plant by product; Cavitation; Sewage treatment plant; Case study; Membrane reactor; Bioreactor; Nozzle; Liquid effluent; Wastes
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2009.01.011

Nozzle-cavitation treatment was used to reduce excess sludge production in a dairy wastewater treatment plant. During the 450-d pilot-scale membrane bioreactor (MBR) operation, when 300 l of the sludge mixed liquor (1/10 of the MBR volume) was disintegrated per day by the nozzle-cavitation treatment with the addition of sodium hydrate (final concentration: 0.01% W/W) and returned to the MBR, the amount of excess sludge produced was reduced by 80% compared with that when sludge was not disintegrated. On the basis of the efficiency of CODCr removal and the ammonia oxidation reaction, it was concluded that the nozzle-cavitation treatment did not have a negative impact on the performance of the MBR. The estimation of the inorganic material balance showed that when the mass of the excess sludge was decreased, the inorganic content of the activated sludge increased and some part of the inorganic material was simultaneously solubilized in the effluent.