| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for removing nitrogen in a membrane separation type oxidation ditch, in which a membrane separation type oxidation ditch is used and both of an aerobic state and an anaerobic state are produced in a circulating water passage, and nitrification and denitrification can be carried out in the oxidation ditch by the combination of the aerobic state and the anaerobic state. <P>SOLUTION: In the oxidation ditch having a long circulating water passage, the circulating water passage formed by water flow controlling walls 3 is divided into an aerobic zone 11 and an anaerobic zone 12. The water flow controlling walls 3 house a membrane separation device 2 as immersed in which the membrane is cleaned by aeration from aeration tubes. The sludge mixture liquid is circulated in such a manner that a part of the sludge mixture liquid is introduced from the bottom of the circulating water passage into the inside of the water flow controlling walls 3 and that the polluted water is injected to the upper part on the upstream side in the aerobic zone 11 while the water is agitated and aerated. Thus, while the membrane separation device 2 is cleaned, nitrification and denitrification of the polluted water are carried out in one oxidation ditch. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
