| 摘要 |
<p>PURPOSE:To prevent the heating up of a biological treating tank and to permit aeration of high load by passing air for aeration in the biological treating tank through an air feed pipe in a cooling tower and cooling the same with cooling water. CONSTITUTION:Waste water 1 contg. a high concn. of BOD components is fed together with return sludge 2 returned from a solid-liquid separating stage 4 into an aerating tank 3 for biological treatment; at the same time, the compressed air 6 fed from a blower 7 is passed through a cooling tower 8 and is thus cooled; thereafter, the water is forced into the tank 3 where the water 1 is treated by oxidation reaction of micro organisms and is then discharged as supernatant water 5 through the solid-liquid separation stage 4 or is further subjected to treatments of higher degrees. The pipe 16 in the tower 8 is formed as a finned 10 or coiled pipe to have a larger heat transfer area, so that the air is cooled by the sensible heat and latent heat of evaporation of the cooling water 14 falling from a packed part 9. The above-mentioned supernatant liquid 5 is usable after treatments of high degrees, besides river water, etc. as the cooling water.</p> |
