| Project/Area Number |
10555192
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
Civil and environmental engineering
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| Research Institution | Nagaoka University of Technology |
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Principal Investigator |
OHASHI Akiyoshi Nagaoka University of Technology, Associate Professor, 工学部, 助教授 (70169035)
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| Co-Investigator(Kenkyū-buntansha) |
ARAKI Nobuo Nagaoka National College of Technology, Associate Professor, 環境都市工学科, 助教授 (30193072)
SEKIGUCHI Yuji Nagaoka University of Technology, Research Assistant, 工学部, 助手 (20313570)
HARADA Hideki Nagaoka University of Technology, Professor, 工学部, 助教授 (70134971)
屋井 裕幸 東急建設(株), 技術本部第5課, 研究員(技術職)
OKUI Yukihiro Tokyu Construction Co.Ltd, Researcher
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| Project Period (FY) |
1998 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥11,000,000 (Direct Cost: ¥11,000,000)
Fiscal Year 2000: ¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1999: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1998: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | developing countries / wastewater treatment / low-cost / microelectrode / FISH / UASB / DHS / nitrification-denitrefication / 硝化 |
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| Research Abstract |
Most of urban areas of developing countries are facing severe deterioration of aquatic environment due to shortage of facilities for basic municipal sewage treatment. Because of the limited financial resources, there is a definite need of a cost-effective appropriate technology for sewage treatment system. Under this practical constraint, anaerobic process could be the most attractive for sewage treatment, since it has advantages over conventional aerobic processes, in such points as no need of aeration and energy recovery benefit through bio-gas production. However, anaerobic processes possess some weak points. Effluent quality of anaerobic process is often not comparable with that from activated sludge process. That is why anaerobic process sometimes requires post-treatment for removal of residual organics and nutrients.
A novel process, which consists of a UASB pre-treatment unit and the following DHS(Downflow Hanging Sponge-curtains)reactor for polishing up the UASB effluent without external aeration input, was proposed in this study. Our proposed system was installed at a municipal sewage treatment plant site, and its feasibility was evaluated by conducting a long-term experiment with actual sewage as a feed. The proposed whole system verified to perform not only superior organic removal but also excellent nitrification at an overall HRT of 8hrs. Microbial analysis and DO microelectrode showed that the DHS reactor had a function of retaining highly density biomass and excellent oxygen-uptake from atmosphere. Over the whole experimental duration of two years no sludge withdrawal was made in our system. A simple model accounted for no excess sludge production in the new system.
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