| Project/Area Number |
61550391
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
都市工学・衛生工学
|
|---|
| Research Institution | Gunma University |
|---|
Principal Investigator |
KURODA Masao Faculty of Engineering, Gunma University, 工学部, 教授 (40008446)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
SAKAKIBARA Yutaka Faculty of Engineering, Gunma University, 工学部, 助手 (80143204)
YUZAWA Megumu Faculty of Engineering, Gunma University, 工学部, 助教授 (30023328)
|
|---|
| Project Period (FY) |
1986 – 1988
|
| Project Status |
Completed (Fiscal Year 1988)
|
| Budget Amount *help |
¥1,700,000 (Direct Cost: ¥1,700,000)
Fiscal Year 1988: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1987: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
|
|---|
| Keywords | methane fermentation / denitrification / symbiosis / acetate / 硝酸イオン阻害効果 / CN同時除去 / 化学的環境因子 / 硝酸イオンのNH_4^+への還元 / 硝酸イオンのNH4+への還元 |
|---|
| Research Abstract |
Methane fermentative bacteria and denitrifying bacteria were enriched with a synthetic medium, and a biofilm was formed on solid support surfaces in a completely mixed reactor. In the medium, glucose, peptone and sodium nitrate were used as carbon and nitrogen sources.
By using the biofilm reactor, characterisitcs of the anaerobic treatment of an aqueous mixture of organic matter and nitrate were studied experimentally, and effects of the C/N ratio on removal efficiencies of TOC and nitrate and effluent characteristics were examined in batch mode and/or continuous operations.
Organic matter and nitrate were removed simultaneously in the anaerobic biofilm reactor, in which methane fermentative bacteria and denitrifying bacteria symbiosed. In the simultaneous treatment, acetate which is an intermediate metaboric product in methane fermentation were effectively utilized by denitrifying bacteria as hydrogen donor. Competition between methanogens and denitrifying bacteria existed on the utilization of acetate. Removal efficiencies of TOC and nitrogen in continuous operations were greater than 94% and 65%, respectively, provided that the ratio of C and N is larger than 2. Both values of ORP and pH increased with the increment of nitrate concentration. Under high nitrate loading conditions, methane gas production decreased.
The degradation rate of NO_3^- was varied with the concentration of NO_3^-. The equation of the degradation rate was expressed with a Monod type equation. The maximum specific degradation rate constant and half velocity constant were 4.6 mg-N/mg-C.D and 10 mg-C/l provided by using acetate as hydrogen donor. The value of the half velocity constant is about half of that for the degradation of acetate by methanogenic bacteria.
|
