| 摘要 |
<p>PURPOSE:To continuously decontaminate waste water at a high efficiency without necessity of separating fine floats, dividing a fluidized bed reaction process into a primary step, where most of organics and NH3-N in the waste water are treated, and the second step, where the residuals are treated, and returning granular carriers after regenerated. CONSTITUTION:Waste water 3 is introduced into a primary fluidized bed type reaction vessel 1, where the waste water is treated with oxygen from an oxygen supplying device 2 and bacteria adhering onto the surface of granular carriers in a fluidized bed 6. The bacteria sufficiently absorb oxygen from the device 2 and flow cyclically in the vessel 1. By this treatment, most of organics and NH3-N are removed, and the denitrificated supernatant water containing the carriers flows into a supplemental oxygen supplying device 11. In the device 11, the treated water is supplemented with a remarkably small amount of dissolved oxygen, as compared with the primary step. The water is then carried into a second fluidized bed type reaction vessel 14, where the water is subjected to the same treatment as the primary step and also to absorption and filtration by a fluidized bed 15. Thus, clean water is obtained. The granular carriers, at the upper layer of the fluidized bed 15, on whose surfaces bacteria excessively grow, are continuously charged through an airlift conduit 20 to a separating device 23. In the device 23, the excessive bacteria are separated from the carriers by a stirrer 22 and the carriers are returned to the vessel 1.</p> |
