| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a treatment method excellent in treatment efficiency of water to be treated, such as sewage. <P>SOLUTION: Aerobic treatment and oxygen-free treatment of the water P to be treated is carried out in this order by using an endless circulating water passage 2 to which the water P to be treated is supplied, a first circulating means 3 having a first rotary vane installed in the water passage 2, and performing air intake into the water P to be treated and circulation of the water P to be treated according to the rotational speed of the first rotary vane, and a second circulating means 4 having a second rotary vane installed in the water passage 2, and performing the circulation of the water P to be treated according to the rotational speed of the second rotary vane without performing air intake into the water P to be treated. The aerobic treatment is carried out by rotating the first rotary vane and stopping the second rotary vane. The oxygen-free treatment is carried out by reducing the rotational speed of the first rotary vane to the highest rotational speed within a range capable of maintaining the DO value of the water P to be treated, at a predetermined value of≤0.3 mg/L, and rotating the second rotary vane. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
