1988 Fiscal Year Final Research Report Summary
Development and application of wastewater treatment system using membrane separation
Project/Area Number |
61850101
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Research Category |
Grant-in-Aid for Developmental Scientific Research
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Allocation Type | Single-year Grants |
Research Field |
都市工学・衛生工学
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Research Institution | University of Tokyo |
Principal Investigator |
MATSUO Tomonori Professor, Faculty of Engineering, University of Tokyo, 工学部, 教授 (80010784)
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Co-Investigator(Kenkyū-buntansha) |
TANAKA Shuzo Associate Professor, Faculty of Eng. & Sci, Meisei Univ., 理工学部, 助教授 (00171760)
HANAKI Keisuke Associate Professor, Faculty of Engineering, Univ. Tokyo, 工学部, 助教授 (00134015)
YAMAMOTO Kazuo Associate Professor, Faculty of Engineering, Univ. Tokyo, 工学部, 助教授 (60143393)
NAKAMURA Tadashi Division Head, Research Institute, Organo Co., 総合研究所, 課長
AYA Hidenori Professor, Faculty of Engineering, Musashi Inst. of Technol., 工学部, 教授 (60010675)
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Project Period (FY) |
1986 – 1988
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Keywords | Membrane separation / Ultra-filtration / Micro-filtration / Biological wastewater treatment / Aerobic process / Anaerobic process / 精密ろ過 |
Research Abstract |
This research project aims at the development of wastewater treatment process in with employing membrane separation for solid-liquid separatikon. This project especially focused on practical aspects and the following results were obtained. (1) Charecteristics of membrane filtration: Uitra membrane and micro membrene in flat type was used to examine the filtration resistance and filtrate water quality when aeration tank of activated sludge was connected with membrane module. Filtrate quality did not at all depend on pore size of membrane. Filtration rate was independent from MLSS in aeration tank, and was not sensitive to pore size of membrane. Accumulation of organic materials of high molecular weight was observed in aeration tank. Molecular weight distribution was examined with gel chromatography. (2) Application of hollow fiber membrane to aerobic wastewater treatment: Hollow fiber membrene of pore-size of 0. 1 micron was directly submerged into laboratoryscale aeration tank of activat
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ed sludge process. Effluent was suctioned through this membrane. Continuous suctioning caused filter clogging problem, while introducing the intermittent suction solved this problem. Successful operation was achieved for nearly one year with MLSS as high as about 40,000 mg/L. However, very high biomass dropped dissolved oxygen level, and COD removal decreased significantly. Application of hollow fiber membrene is very promising as long as intermittent operation is done. (3) Application of membrane separation to anaerobic process: A flat type of membrane was used in combination with mixed-flow type anaerobic reactor. This system enabled long biomass residence time which can not be achieved in conventional anaerobic process. The experiment using milk as a synthetic substrate showad that MLSS reached as high as 15,000 mg/L, and good methane production with excellent effluent was achieved. Filtration flux decreased gradually but the membrene was recovered by cleaning the membrane. Domestic sewage sludge was gtreated in this system. Membrane process can produce 20-40% more methane than conventional process at betention time of 10 days. Immobilization of anaerobic bacteria by using polyvinyl alcohol (PVA) was examined. The obtained beads were stable for reasonably long period, and incubation after the immobilization could raise the biological activity of bacteria. Less
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