RETURN SLUDGE CONTROL DEVICE

摘要

PURPOSE:To control return sludge corresponding to the amt. of bacteria in an aeration tank or the properties of sludge and to prevent the outflow of sludge into discharge water. CONSTITUTION:A return sludge control device is equipped with an automatic measuring means 12 to which the respective signals of the flow rate of raw water and the concn. of MLSS are inputted, an input/output means 13 to which various control parameters can be inputted by an operator and an operation processing means 14. The operational processing means 14 has a return ratio operation means 15 calculating a return ratio capable of returning the load quantity of the sludge flowing in a final sedimentation basin to an aeration tank as return sludge at every definite control cycle on the basis of the concn. of MLSS and an SVI value. The return ratio operation means 15 is connected to a return sludge operation means 16 calculating a return sludge objective value on the basis of the return ratio and the flow rate of raw water to output the same to a return sludge pump at every definite output cycle.