| 摘要 |
<p>A secondary sewage treatment system is provided with vertically-aligned foam collecting (13), turbulent (12), mixing (11), settling (10), and sludge collecting (9) zones. A grating (7) defines the boundary between the turbulent and mixing zones. Beneath the grating (7), a buoyant media (17), such as hollow plastic spheres, are contained and occupy substantially all of the mixing zone. Air diffusers (18) including elongated draft tubes (8) extend from the turbulent zone (12) down through the mixing zone (11) for introduction of air to aerate waste water liquor and to cause the aerated liquor to recirculate up into the turbulent zone, thereby creating a circulation of waste water liquor from the turbulent zone, down through the mixing zone and around the buoyant media, and up through the draft tubes to the turbulent zone.</p> |
