| 摘要 |
<p>PURPOSE:To control accurately descending flow path necessary for economical operation by providing an open-to-the air type head tank portion at the upper end of the descending flow path of circulating path and then by providing a pump by which water is pumped up from the ascending flow path to the head tank portion. CONSTITUTION:The open-to-the air type head tank portion 2 is provided at the upper end of the descending flow path B of the circulating paths A and B to which the oxygen gas supply path 6 for waste water and active sludge is connected, and the pump 5 by which water is pumped up from the ascending flow path A is provided to the head tank portion. And, according to information from the detection mechanism 7 to detect the supply of original water for example, the oxygen gas- containing gas supply control valve 9 is regulated by the control mechanism 8 and also the constant-volume type pump 5 is controlled intermittently and the result of regulating flow rate is fed back to the control mechanism 8 according to information from the detection mechanism 10 for the waste water level of the head tank portion. Thus, it is possible to approximate the amount of oxygen-containing gas supplied to a minimum necessary for the treatment of waste water and also to accurately control the descending flow rate of waste water to as much a small rate as possible.</p> |
