| 摘要 |
PURPOSE:To drastically reduce the setting area and construction cost and to eliminate the need for delicate and skillful maintenance by separating aerobically treated liq. into sludge and permeated water by a filter membrane, separating the permeated water into a concd. liq. and permeated water and biologically nitrifying and then denitrifying the permeated water. CONSTITUTION:Aerobes are charged into a skimmed night soil storage tank 6, air is supplied from an air diffuser 7, and the BOD in screen-separated night soil 5 is removed. The liq. in the tank 6 is force-fed to an UF membrane 8 by a pump, and the aerobes are separated into SS-free UF membrane-permeated water 9 and membrane-separated sludge 10. The permeated water 9 is subjected to reverse osmosis and separated by the membrane into residual org. matter, salts, nitrogen components such as NH3-N and colorants. The NH3-N and NOx-N remaining in the RO membrane-permeated water 12 are introduced into a biological nitrifying and denitrifying stage 15 and removed. Accordingly, good-quality water 16 is obtained. |
