| 摘要 |
<p>PURPOSE:To stabilize SS amt. at all times by calculating the removal amt., removal start time and removal stop time of the excess sludge required for minimizing the calculated value for one day of deviation with respect to the target value of the SS concn. in the liquid mixture in an aeration tank and controlling a sludge return and removal mechanism in accordance with the results of the calculation. CONSTITUTION:An SS concn. detector 110 which detects the SS concn. of the liquid mixture in an aeration tank 10 and a pattern setting circuit 113 which stores the change chracteristic of the inflow rate in a day of the sewage flowed, into the tank up to the previous day and the change characteristic of the SS load and outputs the pattern signal thereof are provided. An arithmetic control circuit 116 which stores the rate of inflow sewage, the SS load of the outflow sewage, and the change characteristic of the SS concn. in the liquid mixture with respect to the amt. of return sludge, is inputted with the signals from the detetor 110 and the circuit 113, calculates the removal amt., removal start and stop time of the surplus sludge required for minimizing the integrated value for one day of deviation with respect to the target value of the SS concn. in the liquid mixture in accordance with said signals and controls the removal mechanism in accordance with the calculated results is provided.</p> |
