Elucidating mechanisms of activated sludge reduction by a high-pressure jet device

2017 Fiscal Year Final Research Report

• Project/Area Number: 26249076
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Civil and environmental engineering
• Research Institution: Tokyo University of Agriculture and Technology
• Principal Investigator: Hosomi Masaaki 東京農工大学, 工学(系)研究科(研究院), 教授 (90132860)
• Co-Investigator(Kenkyū-buntansha): 堀 知行 国立研究開発法人産業技術総合研究所, エネルギー・環境領域, 研究グループ付 (20509533) ; 寺田 昭彦 東京農工大学, 工学(系)研究科(研究院), 教授 (30434327)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 高圧ジェット装置 / 汚泥減容化 / 活性汚泥 / 圧壊 / 排水処理 / 16S rRNA / 酸素富化

Outline of Final Research Achievements

To reduce the amount of excess sludge from a wastewater treatment facility, a high-pressure jet device (HPJD) was developed. Bacterial cell disruption mechanisms by an HPJD were investigated. The application of an atomic force microscopy to a single bacterial cell elucidated that cavitation is most intense factor to disrupt bacterial cells among friction, collision and itself. The installation of an HPJD into a modified Ludzak-Ettinger process reduced the amount of excess sludge discharge by, at maximum, 73% in comparison with the process without an HPJD. Deterioration of water qualities of the treated water and settlability of activated sludge due to an HPJD was not observed. The analysis of amplicon sequencing based on 16S rRNA gene displayed the reduction of filamentous bacteria in the process with an HPJD, suggesting an effectiveness in prevention of sludge bulking.

Free Research Field

環境化学工学