PARTIAL AERATION METHOD IN SEWAGE AND NIGHT SOIL TREATMENT

摘要

PURPOSE:To run activated sludge, etc. efficiently by segmenting the longitudinal direction of an aeration tank or nitrification tank properly, and providing measuring devices which detect dissolved oxygen (DO) concns. of the liquid in the chambers in the respective segmented chambers. CONSTITUTION:Inflow water B flows together with return sludge 9 into an aeration tank 1, and after activated sludge treatment, the sludge is separated in a settling tank 2. The supernatant is discharged as outflow water 12. The aeration air is divided to a plurality, and after the flow rates are controlled with dampers 3, they are supplied into each of the segmented chambers 13 segmented by means of partition plates 15. Oxygen is dissolved in water through air diffusers 14. The sample liquid drawn from sampling pipes 7 is fed into a DO densitometer 5, by which the DO concns. in the chambers 13 are detected time dividedly. A controller 6 operates the openings of the dampers 3 in accordance with the detected DO concn. values, thereby controlling the flow rates of the aeration air 11 to the chambers 13.