METHOD AND APPARATUS FOR MEASURING OXYGEN UTILIZATION SPEED IN AERATION TANK

摘要

PURPOSE:To accurately measure an oxygen utilization speed by aerating the supernatant liquid of the liquid mixture in a tank to increase the concn. of oxygen to a saturated state and receiving the same in the same container as the liquid mixture to be measured and performing measurement of every kind after required operation. CONSTITUTION:The liquid mixture in an aeration tank 1 is subjected to sedimentation separation and the supernatant liquid is received in an oxygen supply tank 5 and aerated by an aerator 6 to increase the concn. of dissolved oxygen to an almost saturated state (8mg/l). This aerated liquid is supplied to a hermetically closed type reactor 10 by a pump 8 and, at the same time, the liquid mixture to be measured in the tank 1 is also supplied to the reactor 10 by a pump 3. Since the dissolved oxygen of the supernatant liquid in the saturated state from the tank 5 is reduced rapidly when both of them are perfectly mixed by a stirrer 11, the flow rates of the pumps 3, 8 are controlled so that the concn. of dissolved oxygen in the reactor 10 becomes equal to that in the tank 1. From the various flow rates and the concns. of oxygen at that time, an oxygen utilization speed can be calculated according to a predetermined formula. By this method, measurement can be performed simply and accurately and the control of the apparatus becomes easy.