| Project/Area Number |
10555187
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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 | Gunma University |
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Principal Investigator |
KURODA Masao Gunma Univ., Faculty of Eng., Professor, 工学部, 教授 (40008446)
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| Co-Investigator(Kenkyū-buntansha) |
WATANABE Tomohide Gunma Univ., Faculty of Eng., Research Associate, 工学部, 助手 (60251120)
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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 |
¥5,400,000 (Direct Cost: ¥5,400,000)
Fiscal Year 2000: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1999: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1998: ¥3,000,000 (Direct Cost: ¥3,000,000)
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| Keywords | Bioelectrochemical reactor process / Advanced treatment / Nitrification / Denitrification / Electrolysis of water / Dissolved oxygen / 廃水処理 / アンモニア性窒素 / 硝酸性窒素 / 溶存酸素濃度 |
|---|
| Research Abstract |
1. Effects of current density and DO concentration in bulk solution on nitrification and denitrification were investigated separately in bioelectrochemical process. Nitrification rate and denitrification rate per unit area of electrode were increased with an increase in current density in the range up to 0.3 mA/cm^2. Even under the condition of relatively low DO concentration, nitrification proceeded by utilizing oxygen derived from electrolysis of water at anode. Denitrification rate decreased with an increase in the bulk DO concentration, but denitrification proceeded even under 5 mg/L of DO concentration.
2. Continuous TN removal experiments were carried out by using a reactor in which a pair of electrodes that nitrifying and denitrifying bacteria were attached on was immersed. The results showed that TN was removed without accumulation of nitrite by applying electric current, regardless of the bulk DO concentration up to 5 mg/L.
3. Feasibility of bioelectrochemical method for improve
… More
ment of nitrogen removal performance in submerged biofilter process for treatment of domestic wastewater was investigated experimentally. Packed beds of activated carbon were used as anode and cathode and immersed in the aerobic tank. Nitrification and denitrification rates increased by applying electric current. Optimum bulk DO concentration to give the largest nitrogen removal rate was in the range of 1.5-2.0 mg/L.
4. Based on a biofilm model describing the bioelectrochemical process by considering mass transfer, biological reaction and electrochemical reaction, nitrification and denitrification rates were calculated numerically. The calculated results indicated that high nitrification rate arose from the formation of aerobic condition in whole anodic biofilm by applying electric current. When the bulk DO concentration was below 3 mg/L, far region of cathodic biofilm from the bulk could be kept anoxic condition due to biological oxygen consumption and high hydrogen utilization efficiency for denitrification was maintained. Less
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