| 摘要 |
<p>Sewage purificn. plant for small communities, based on the "total oxidn." or extended aeration process, comprises a conical tank, a cone section deliminting a decantation zone towards the outside and an oxidn. zone towards the inside, and a thick layer of glass wool on the cone. This breaks up the air bubbles introduced at the base of the oxidn. zone from a compressor, and also retains the activated sludge recirculated through the slits. The water to be purified is introduced at the base of the oxidn. zone and passes through the opening to the decantation zone; this is divided into four cells by partitions with holes located alternately at the top and the bottom. Heavy matter separates out and is recirculated through the slits; they rise towards the last opening in the upper part of the plant and bring any "bulked" sludge, which is lighter than water, to the surface. Preferential circulation of the fluid in the decantation zone improves the retention time. The oxidn. yield is good and the final effluent is free from suspended solids.</p> |
