2003 Fiscal Year Final Research Report Summary
Development of a membrane-aerated biofilm reactor applicable to livestock wastewater
| Project/Area Number |
12555219
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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 |
化学工学一般
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| Research Institution | Waseda University |
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Principal Investigator |
TSUNEDA Satoshi Waseda University, School of Science and Engineering, Associate Professor, 理工学部, 助教授 (30281645)
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| Co-Investigator(Kenkyū-buntansha) |
HIBIYA Kazuaki Japan Society for the Promotion of Sciences, Research Fellow (DC1), 理工学研究科・日本学術振興会, (DC1)特別研究員
KUBOTA Noboru Asahi Kasei Chemicals Corporation, Industrial Membranes Division, Chief Researcher, 機能膜技術開発部, 主任研究員
HIRATA Akira Waseda University, School of Science and Engineering, Professor, 理工学部, 教授 (00063610)
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| Project Period (FY) |
2000 – 2003
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| Keywords | Livestock wastewater / Wastewater treatment / Biofilm / Nitrifying bacteria / Denitrifying bacteria / Biological nitrogen removal / Hollow-fiber membrane / Membrane aeration method |
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| Research Abstract |
The discharge of livestock wastewater that contains high concentration of nitrogen causes eutrophication, algal blooms and groundwater pollution. We developed a membrane-aerated biofilm reactor (MABR) capable of simultaneous nitrification and denitrificaiton (SND) in a single reactor.
1.Analysis of dissolved oxygen (DO) profile in biofilms
DO profile in biofilms of several thicknesses was investigated using an oxygen microelectrode. From this experiment, a large anaerobic zone was observed at the bottom of the thick biofilm. This result clearly indicated the possibility that quite different microenvironment is created in a same biofilm, allowing for SND.
2.Feasibility of SND using the MABR
Feasibility of SND on the MABR for treatment of domestic wastewater was conducted for 150 days. After 50 day, removal efficiencies of organic carbon and nitrogen were more than 90%, which indicates that SND can be accomplished using the MABR.
3.Application of the MABR to livestock wastewater
The removal characteristics from livestock wastewater were investigated for 1 year. Average removal efficiencies of organic carbon and nitrogen were 96% and 83% at removal rates of 5.76 g-C/(m^2・day) and 4.48 g-N/(m^2・day), respectively. The combination of the in situ detection of specific bacteria and determination of the DO microprofiles made it possible to prove the mechanism of SND and the microbial ecology in the biofilm. Furthermore, nitrogen removal not via nitrate but nitrite was mainly achieved in the MABR system. The MABR takes advantage of the easy control of oxygen mass transfer, and thus it is useful when removing nitrogen from low carbon/nitrogen-ratio wastewater such as livestock.
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