| 摘要 |
<p>PURPOSE:To decrease aeration rates and to stably clean waste water over a long period of time by dividing an aeration tank to 3 tanks and specifying the aeration rates with respect to the liquid volumes in the respective tanks. CONSTITUTION:The aeration tank is divided to the 3 tanks in an activated sludge treatment of industrial waste water, living waste water, etc. Sludge bacteria absorb the org. matter in the waste water and partly oxidize and decompose the org. matter in the front tank. The sludge bacteria decompose and metabolize the adsorbed org. matter in the middle tank and the sludge bacteria are activated in the rear tank. The aeration rates are, thereupon, adjusted to 0.5-0.8 in the front tank, 0.1-0.4 in the middle tank and 0.1-0.3 in the rear tank per minute in volume ratio with respect to the liquid volumes in the tanks. The pH of the liquids in the tanks is adjusted to >=6.0 and <=7.0. The pH in the front tank is adjusted to the lowest value, i.e., about 6.0-6.5, the pH in the middle tank to about 6.0-6.7, and the pH in the rear tank to about 6.3-7.0. The aeration rates are thus lowered, by which the cost is reduced and the cleaning of the waste water is stably executed over a long period of time.</p> |
