| 摘要 |
<p>PURPOSE:To remove the living particles flowing out from a fluidized bed type biological treatment device efficiently by providing an intermediate aeration vessel disposed with particle capturing materials in the inside and disposed with an air diffuser between said biological treatment device and a solid-liquid separating device. CONSTITUTION:If sewage treatment is carried out in a fluidized bed type biological treatment device 1, the biological membranes stripped from carrier surfaces by the impact owing to the bubbles of gases contg. oxygen and the velocity of circulating flow are made into fine particles, and are flowed out together with the treated water in the state of poor settleability. This outflow water is flowed into an intermediate aeration vessel 5, where floc diameters of living particles are increased, thence the water is shifted into a solid-liquid separating vessel 6, where it is subjected to solid-liquid separation. The living particles in the inflow water in the vessel 5 stuck on particle capturing materials 7, and when the thickness thereof >5mm., the biological membranes thereof peel and dislodge. The peeled living particles are large in floc diameters and therefore the settling of the living particles in the vessel 6 is easily and the efficiency of the solid-liquid separation is improved.</p> |
