Method and apparatus for measuring oxygen utilization rate of aeration tank

摘要

PPROBLEM TO BE SOLVED: To improve the precision of measurement without requiring a large-scale measuring apparatus such as by a gas balance method. PSOLUTION: Oxygen-saturated supernatant liquid c and oxygen-free supernatant liquid d are fed to a closed rr measuring device 4 filled with mixture liquid (a) of an aeration tank 11 while inverter-controlling the flow rates of the supernatant liquids so as to maintain a constant relation among the flow rates of the oxygen-saturated supernatant liquid c, the oxygen-free supernatant liquid d, and oxygen-free sludge e and make DO in the closed rr measuring device 4 coincide with DO in the aeration tank 11. An oxygen utilization rate rr is determined from the DO and integrated flow rate of the oxygen-saturated supernatant liquid c, the integrated flow rates of the oxygen-free supernatant liquid d and the oxygen-free sludge e, and a measuring time after the coincidence of the DO in the closed rr measuring device 4 with the DO in the aeration tank 11. PCOPYRIGHT: (C)2005,JPO&NCIPI