METHOD AND APPARATUS FOR CONTROLLING EFFLUENCE OF SUPERNATANT WATER IN SEWAGE TREATMENT CHAMBER

摘要

PURPOSE:To assure the quality of treated water by using a transmission type optical sensor, and executing effluence of supernatant water only when the layer of the supernatant water is sufficiently deep and there is no possibility of sludge intrusion therein and stopping the effluence automatically when the layer of the supernatant water is shallow and the sludge intrusion is anticipated. CONSTITUTION:A float 1 is provided afloat in a sewage treatment chamber 4 provided with an aerator 2 and a supernatant water effluent device 3 so as to move upward and downward according to the water level in the chamber. A light projecting face 7a and receiving face 7b of a transmission type optical sensor S are disposed to face said float 1 at a prescribed spacing therefrom to constitute a sensing part 7 interposed with the in-chamber liquid between said opposite surfaces. The buoyance of the float 1 is so set that the sensing part 7 is positioned at a prescribed arbitrary depth under the water surface in the chamber 4. The sensor is thus so constituted that the increase or decrease of the transmitted light generated by arrival of the settling boundary l2 of the sludge at the sensing part 7 is detected. As a result, the intrusion accident of the sludge is prevented and the quality of the treated water is assured.