| 摘要 |
<p>PURPOSE:To diminish the variation of an amount of bacteria in a biological disposal tower and to stabilize its disposability, by arranging one or more carrier-discharge pipes at a height near the boundary of the most suitable fluidized bed in the biological disposal tower provided with a purified water-discharge opening at its upper part. CONSTITUTION:A carrier having bucteria adhered thereto is packed in a disposal tower 1. Water to be treated is introduced through a water-inflow pipe 6, a fluidizing pump 7 and an inflow pipe 8 into the lower portion of the disposal tower 1, to form a fluidized bed 2. The water to be treated is biologically purified with bacteria adhered onto the carrier during its ascension through the fluidized bed, and discharged through a drain pipe 4. When the operation is continued, the bacteria on the surface of the carrier grow and the expansion magnification of the carrier increases. As a result, the boundary 3 of the fluidized bed rises. Before the carrier outflows through the drain pipe 4, the carrier and water are extracted through a carrier-discharge pipe 5 to lower the boundary 3 to the most suitable level.</p> |
