| 摘要 |
<p>PROBLEM TO BE SOLVED: To stably feed the required quantity of air regardless of frequency of a power source by feeding the quantity of the air required for aerobic operation which is carried out in a treatment tank by using a diaphragm type pump which is activated at a resonance frequency by inverter control. SOLUTION: This septic tank 1 is internally partitioned to a foreign matter removing tank 4, the treatment tank 2 and a disinfecting tank 5, an air diffusing pipe 15 is disposed on the lower part of the treatment tank 2 and a membrane unit 13 is disposed on the upper part of the air diffusing pipe 15. Therein, the pump 14 is operated, the air is fed into the treatment tank 2 from the air diffusing pipe 15, thereby, the aerobic operation is carried out, ammonia which flows into the treatment tank 2 is oxidized and is changed to nitric acid and nitrous acid. In order to secure the quantity of the air required for the aerobic operation executed in the treatment tank 2, the pump 14 is set so as to use the diaphragm type pump which is activated at the resonance frequency by the inverter control, the power source is changed to the prescribed resonance frequency and, thereby, the air feeding quantity of the pump 14 can be controlled to the prescribed quantity of the air.</p> |
