OPERATING METHOD OF AERATION STIRRER OF SINGLE TANK TYPE ANAEROBIC AND AEROBIC ACTIVATED SLUDGE METHOD

摘要

PURPOSE:To effectively progress the oxidation under an aerobic condition and the denitrification and dephosphorization under an anaerobic condition by operating a stirring mechanism in such a manner that the rotating speed of the stirring mechanism at the time of aeration and the rotating speed of the stirring mechanism at the time of the stop of the aeration vary. CONSTITUTION:The rotating speed of stirring vanes is varied by a controller 5 in the case of using a submersible aerator 3 or a propeller. An inverter or VS motor is adequately used to change the rotating speed. Sewage flows through an inflow pipe 8 into an aeration tank 1 and the oxidation decomposition by aeration or denitrification or the taking in of org. matter under the anaerobic condition is executed. The liquid mixture of an aeration tank 1 is sent via a piping 14 to a settling basin 2 and is subjected to a solid-liquid sepn. to treated water and sludge in this settling basin 2. The supernatant, thereafter, flows as the treated water 9 to the outside of the system and the separated and concentrated sludge is returned as return sludge via a return piping 10 to the aeration tank 1 by a pump 11. A part of the return sludge is properly discharged as excess sludge via an excess sludge withdrawing pipe 16 by a pump 15.