WASTE WATER TREATMENT CAPABLE OF CONTROLLING AERATION CONDITION OF INTERMITTENT AERATION BASED ON SETTLING VELOCITY OF SLUDGE

摘要

PURPOSE:To decompose organic materials, and to remove nitrogen with a high rate by using the settling velocity of sludge which is in correlation with the ratio of nitric nitrogen to ammoniacal nitrogen in the water to be treated as an index, and controlling automatically the aeration and nonaeration time. CONSTITUTION:The settling velocity of sludge which is in correlation with the ratio of nitric nitrogen to ammoniacal nitrogen in the water to be treated is used as an index, and the aeration and nonaeration time are automatically regulated, and the aeration and nonaeration are alternately repeated in the same vessel, and the nitrogen is removed with a high rate. In a batch operation wherein intermittent aeration, settling, and discharge are carried out, the settling velocity of the sludge is detected when the sludge is settled before discharged, and the detected velocity value is incorporated into an electrical circuit so that the intermittent aeration time may be regulated in accordance with the ratio of the aeration time to nonaeration time. In addition, when the inside of the vessel becomes more anaerobic, the aeration time is automatically prolonged in relation to the nonaeration time.