| 摘要 |
<p>PURPOSE:A control unit of excess sludge flow rate which is able to maintain the weight of the sludge stagnating in the system always at a proper value with ease by obtaining the weight of the sludge stagnating in a final sedimentation basin accurately through calculation and obtaining the measured value of the weight of the sludge in an aeration tank etc. CONSTITUTION:This control unit for excess sludge flow rate is provided with an aeration tank 2 supplying waste water, activated sludge and air and a final sedimentation basin 3 making solid-liquid separation of the mixed liquid flowing out from this tank 2 into treated water and activated sludge. The activated sludge accumulated in the bottom of the basin 3 is drawn and part thereof is returned 4 into the tank 2. The excess activated sludge is discharged 9 to outside the system. Next, the weight of the sludge stagnating in the basin 3 is accurately obtained through calculation based on the model of the basin 3 and the weight of the sludge in the tank 2 etc. is obtained by measuring MLSS concentration etc. From these calculated value and measured value, the weight of the sludge stangating in the system are accurately and easily obtained whereby the weight of the stagnating sludge is maintained at a proper value at all times.</p> |
