| 摘要 |
<p>PURPOSE:To facilitate the removal of the clogging materials in washing cycles by making combination use of particles having smaller particle sizes and higher specific gravities with particles having larger particle sizes and lower specific gravities as carrier particles and forming an upper stationary bed of a tank with the latter particles. CONSTITUTION:The carrier of smaller particles 3 are charged on a perforated plate 2 placed near the bottom of a treating tank 1 of semifluidized beds, whereby a lower fluidized bed (a) is formed. The carrier of larger particles 4 are charged thereon, whereby an upper stationary bed (b) is formed. A supply pipe 6 for raw water is connected to the lower part of the tank 1 and an outflow pipe 7 for treated water is connected thereto. Raw waste water is first introduced through an inflow pipe 9 into an oxygen dissolving device 8 where the water dissolves sufficiently oxygen supplied through a blowing pipe 13. This water is supplied through the pipe 6 into the tank 1 where the water suffers biological treatments while it passes through the bed (a) and the bed (b). The treated water is discharged thrugh the pipe 7 at the upper part of the tank 1.</p> |
