| 摘要 |
<p>PURPOSE:To offer an efficient and constructionally simple waste water decontamination apparatus where nitrification and denitrification are carried out in one treating vessel, by dividing the treating vessel using granular solid floats into an upper nitrification zone and a lower denitrification zone. CONSTITUTION:In a treating vessel 1, a packed layer 2 composed of such solid grains as foamed styrene capable of floating in the water is formed under a float- preventing member 3 such as an upper perforated sheet. A stock solution containing NH3-N flows downwards in the layer 2 through an inlet pipe 5. In a nitrification zone above an air injector 4, nitrification reaction is carried out by aerobic bacteria adhering onto the solid floats with oxygen carried as bubbles from the injector 4. During this reaction, the flow speed of the stock solution is maintained slower than the upward flow speed of the bubbles, so that the denitrification zone under the injector 4 is kept in an anaerobic atmosphere. The stock solution is denitrificated by an organic carbon source such as methanol charged through a pipe 6, and the treated solution is discharged through a pipe 7. In case where the stock solution contains organics, part of the treated solution is recycled through a conduit 9, while the stock solution is charged through a pipe 6 into the treating vessel.</p> |
