| 摘要 |
<p>PURPOSE: To make a settling tank of a biological sewage treating device compact by setting an organism immobilizing carrier in, an aeration tank or in an anaerobic tank and throwing in a granular solid material having a specified grain diameter. CONSTITUTION: A granular solid material 4 is thrown in an aeration part 1, an immobilized organism immobilizing carrier 3 is set at an intermediate height of the aeration part 1. Raw water 5 is introduced from the lower part of the aeration part 1, and air 8 is blown in from the lower part of the aeration part 1. Consequently, the org. component in the raw water is brought into contact with activated sludge, and the org. matter is decomposed and removed. The activated sludge is deposited on the carrier 3, and the amt. of immobilized activated sludge is increased. Accordingly, even if the concn. of activated sludge is lowered in a fluidized region, the concn. of the activated sludge effective in the entire treatment of the aeration part 1 is maintained at the same concn. as before. Further, the settling velocity of activated sludge is increased and the water surface area of a settling part 2 is decreased by throwing in the granular solid material 4 having <=100μm grain diameter.</p> |
