CONTROL METHOD OF AEROBIC-ANAEROBIC ACTIVE SLUDGE PROCESS

摘要

PURPOSE:To maintain the reaction rate of nitrification and to downsize a nitrification tank in an aerobic-anaerobic active sludge process by attaching a thermometer and a pH meter to the nitrification tank and increasing the pH value set as the temperature in the nitrification tank decreases. CONSTITUTION:A thermometer 20 and a pH meter 9 are attached to the upstream part of a nitration tank 2, and the reaction rate of nitration is determined by a reaction rate arithmetic unit 21 corresponding to the temperature measured by the thermometer. The relationship between the temperature and the reaction rate is determined in advance, and the temperature is regulated so that a desirable reaction rate can be maintained. The pH value is set by a pH setting unit 22 corresponding to the reaction rate determined. The reaction rate is affected by pH which in general decreases with the progress of the reaction and concurrently causes a decrease in the reaction rate. When the pH value decreases remarkably, an alkaline agent 12 is added to restore the value to around 6 to control the reaction rate.