| 摘要 |
<p>PURPOSE:To enhance the quality of treated water by forming a microorganism phase excellent in precipitation property, by calculating the relative emergent rate of a microorganism from a fibriform or flockform microorgaism, and regulating an operation amount affecting the development of the microorganism from said relative emergent rate. CONSTITUTION:Inflow water 3 containing an org. substance and return sludge 4 containing activated sludge are introduced into an aeration tank 1 and air 7 is injected into said tank 1 from an air diffusion pipe 8. In a precipitation basin 2, the solid-liquid separation of the effluent liquid from the aeration tank 1 is performed and the supernatant liquid is discharged as treated water 5 and the greater part of precipitated activated sludge is recirculated to the aeration tank 1 as the return sludge 4 while a part thereof is withdrawn out of the system as excessive sludge 6. In this process, operation is performed on the basis of the microorganism phase in activated sludge. A microorganism phase judging apparatus 11 collects an activated sludge liquid mixture from the aeration tank 1 by a sampling pipe 9 and the microorganism phase in this liquid, that is, a fibriformmicroorganism and a zoogloea microorganism are determined.</p> |
