Patent ID: 6569335
Filing Date: 2003-05-27
Classification: C02F,Y02W

Abstract:
A method for controlling an activated sludge wastewater treatment process in which influent wastewater is mixed with activated sludge in an aeration tank to form a mixed liquor, the mixed liquor being directed to a clarifier wherein a portion of the activated sludge settles from the mixed liquor such that a portion of the settled activated sludge, the return activated sludge, is drawn from said clarifier and returned to said aeration tank and the remaining settled activated sludge, the waste activated sludge, is wasted from said clarifier, comprising:measuring the suspended solids concentration in the waste activated sludge, WASSS, and the aeration tank, MLSS; providing a data processor having at least one data structure storing the volume of the aeration tank, VAerationTank, and an input device; communicating the MLSS and WASSS measurements to said data processor; inputting at said input device a desired solids retention time, SRTDesired; said data processor calculating the flow rate of the waste activated sludge, WAS flow rate, according to the formula: WAS&it;â€ƒ&it;flow&it;â€ƒ&it;rate=MLSSÃ—VAerationTankSRTDesiredÃ—WASSS;â€ƒ&it;andcontrolling the flow rate of the waste activated sludge in response to said calculated WAS flow rate.