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Removal of Nitrate Nitrogen in Drinking Water with Hollow Fiber Bioreactor

中空纤维生物反应器去除饮用水中的硝态氮

基本信息

批准号：
14550774
负责人：
HATANAKA Chiaki
金额：
$ 2.24万
依托单位：
Kitakyushu National College of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

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.

采用孔径为0.1μm的聚乙烯醇亲水性聚砜中空纤维作为固定化氢氧化菌(Paracoccus Denitriicans)的载体。通过聚乙烯醇为介质，将细菌固定在中空纤维表面。在管式反应器中设置纤维组件，向纤维外表面引入含有硝态氮的人工地下水，从中空纤维内侧输送还原硝酸盐所需的氢气。氢氧化菌是自养的，只需要一种无机碳，微生物的增殖率和反硝化速率都能维持在6.0mg/L的无机碳水平上。在pH值为6.5~9.5范围内，反硝化速率也保持在较高水平，从而揭示了地下水中硝态氮浓度对反硝化速率的影响。测定并绘制了人工地下水中硝酸盐浓度在20 mg/L~400 mg/L范围内的反硝化速率曲线。在浓度范围内(r：反硝化速率[mg-N/m2.h]，C：硝态氮浓度[mg/L])，反硝化速率近似为r=52.2C^&lt；0.79&gt；结果表明，在硝酸盐水平较低时，氢氧化菌等自养菌的反硝化速率明显高于异养菌，除硝酸盐外，自养菌还需要磷、钾、镁等微量元素进行反硝化。通过对pH值、微量元素水平、氢气温度和压力等因素的优化，获得了较高的反硝化率。论证了中空纤维生物反应器用于去除地下水中硝酸盐的可能性。