NITRIFICATION ACCELERATING METHOD FOR ACTIVATED SLUDGE CIRCULATION MODULATING METHOD AND METHOD FOR PREDICTING NITRIFICATION RATE

摘要

PURPOSE:To provide a nitrification accelerating method of an activated sludge circulation modifying method which enhances the denitrification effect in anaerobic tank by accelerating nitrification in aerobic tanks and a method for predicting nitrification rates. CONSTITUTION:This activated sludge circulation modifying method treatment includes a stage for denitrifying raw water 3 in the anaerobic tank 1, a stage for nitrification this water in the aerobic tanks 2a to 2c and a stage for subjecting the water to sepn. of solid from liquid in a final settling basin 7 and releasing the supernatant liquid as treated water 11. While a flow meter 15 for the raw water 3 to be admitted into the anaeration tanks 1a to 1b is disposed, an ATU-Rr meter 16 is installed at the upstream part of the aerobic tanks 2a to 2c. This nitrification accelerating method comprises estimating the nitrification rates in the aerobic tanks 2a to 2c from the oxygen consumption and dissolved oxygen quantity based on the nitrification reaction and executing DO control 20 so as to permit SRT control 21 for the purpose of assuring the target nitrification rates according to these values and the inflow rate of the raw water 3. This method for predicting the nitrification rates comprises predicting the nitrification rate in the nitrifying vessels in accordance with the SRT control based on the prediction of the water temp. and nitrification reaction model equation.