NITRATION LIQUID CIRCULATION CONTROL OF AEROBIC ANAEROBIC ACTIVE SLUDGE METHOD

摘要

PURPOSE:To accelerate a denitrification reaction speed, and at the same time, optimize nitration liquid circulation control in a nitration liquid circulation method by which, to return a nitration liquid in a last stage aerobic tank used in an aerobic/anaerobic active sludge process to a front stage aerobic tank for circulatory denitrification. CONSTITUTION:A circulation control valve 7b is provided in the last stage tank of an aerobic tank 2, and a circulation control valve 7b and a respiration speed gauge 8 are installed in the aerobic tank 2 one stage before or after the last stage tank. A nitration liquid circulation control part 9 interprets the degree of nitration in accordance with the measurement value of the respiration speed gauge 8. For example, if the nitration is sufficient, the part 9 closes the valve 7a and, at the same time, opens the valve 7b. On the other hand, if the nitration is insufficient, the part 9 closes the valve 7b, and at the same time, opens the valve 7a.