| 摘要 |
PURPOSE:To reduce the amt. of sludge production and to reduce treatment costs by adding a ferrous flocculating agent to mixed slurries of the biologically treated water of ammonia-contg. org. waste liquid and excess sludge then subjecting these to solid-liquid sepn. under acidic conditions. CONSTITUTION:Crude night soil 31 in an undiluted state is flowed into a biological denitration and denitrification stage 32, where it is removed of BOD components and nitrogen components. Concd. and separated water 42 are mixed with the balance of an outflowed slurry 39 to make mixed slurries 43 which are flowed into a flocculating tank 44. The mixed slurries 42 are mixed with excess sludge contg. BOD nourishing germs, nitrifying germs, etc. A ferrous flocculating agent such as ferrirc chloride is added to the slurries 42 in the tank 44, and under the oxidation conditions of 2.5-5.5pH, they are separated to concd. sludge 48 and screen-separated water 47 by a screen 46. The water 47 is controlled to 6.0-7.0pH and is removed of BOD in an aerobic biological treatment stage. |
