2004 Fiscal Year Final Research Report Summary
Removal of Nitrate Nitrogen in Drinking Water with Hollow Fiber Bioreactor
| Project/Area Number |
14550774
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
生物・生体工学
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| Research Institution | Kitakyushu National College of Technology |
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Principal Investigator |
HATANAKA Chiaki Kitakyushu National College of Technology, Material Science & Chemical Engineering, Professor, その他部局等, 教授 (80180884)
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| Co-Investigator(Kenkyū-buntansha) |
IDE Shunsuke Kitakyushu National College of Technology, Integrated Arts & Science, Professor, その他部局等, 教授 (10041550)
GOTO Muneharu Kitakyushu National College of Technology, Material Science & Chemical Engineering, Assistant Professor, その他部局等, 助教授 (40259966)
MIZUNO Kouhei Kitakyushu National College of Technology, Material Science & Chemical Engineering, Assistant Professor, その他部局等, 助教授 (80342583)
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| Project Period (FY) |
2002 – 2004
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| Keywords | ENVIRONMENTAL AND SAFTY ENGINEERING / SEWAGE TREATMENT / NITROGEN REMOVAL / DENITRIFICATION / HOLLOW FIBER BIOREACTOR / HYDROGEN-OXYDIZING BACTERIA / IMMOBILIZED MICROORGANISM |
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| Research Abstract |
We used the polysulphone hollow fibers, which were hydrophilized by polyvinyl alcohol with pore of 0.1μm, as the supporter for the immobilization of hydrogen-oxidizing bacteria(Paracoccus denitrificans). The bacteria were immobilized on the surface of the hollow fiber through the medium of polyvinyl alcohol. The fiber module was furnished in the tubular reactor and the artificial ground water containing nitrate nitrogen was introduced to the outer surface of the fiber and hydrogen needed for reduction of nitrate was delivered from the hollow fiber's inner side. The hydrogen-oxidizing bacteria are autotrophic and need only an inorganic carbon and then the rate of multiplication of the microorganism and denitrification rate was maintained adequately at level of 6.0 mg/L of inorganic carbon. The denitrification rate was also maintained high level at the range of pH6.5 to pH9.5.
Subsequently we showed the influence of concentration of nitrate nitrogen in ground water on the rate of denitrification. The rate of denitrification at concentration of nitrate in artificial ground water varied from 20 mg/L to 400 mg/L were measured and plotted. The rate was approximated by r=52.2C^<0.79> at the range of the concentration (r : rate of denitrification [mg-N/m^2・h], C : concentration of nitrate nitrogen in [mg/L]). It was appeared that the rate of denitrification of autotrophic bacteria such as the hydrogen-oxidizing bacteria was sufficiently high at lower level of the nitrate than the level in heterotrophic bacteria.
The bacteria needed the some trace elements such as phosphorous, potassium and magnesium other than nitrate for denitrification. High denitrification rate were attained by the optimization of pH, the level of trace elements, temperature and pressure of hydrogen gas so on. The possibility of application of hollow fiber bioreactor for removal of nitrates in the ground water was shown.
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