| 摘要 |
<p>PURPOSE:To prevent the lowering of treatment efficiency by injecting at least a part of treated waste water to the air diffusion device of a treatment tank from the part equal to or higher than the upper surface level of the air diffusion device. CONSTITUTION:A nozzle 12 is provided to the leading end of a circulation route pipe 9 itself or the leading end of the pipe branched from said pipe 9 and treated waste water is injected to the blowoff part of an air diffusion device 6 aerating waste water with oxygen 11 on the upper surface side of the device 6. By this method, the accumulation of carrier particles on the blowoff part can be prevented and the lowering of oxygen moving efficiency due to clogging or an increase in the size of air bubbles for aeration can be prevented. Therefore, the aeration with oxygen in a necessary level or more has been performed heretofore as a means preventing the clogging of the blowoff part of the air diffusion device but this necessity is eliminated and power cost for the aeration with oxygen can be reduced.</p> |
