| 摘要 |
PROBLEM TO BE SOLVED: To provide a treatment method for org. sewage which removes phosphorus and nitrogen at a high speed, obviates the generation of excess sludge, eliminates the need for the incineration equipment to be exclusively used for sludge and obviates the elution of heavy metals from incineration ashes. SOLUTION: A flocculating agent 10 is added to the org. sewage 8 of sewer, etc., to execute flocculation and sepn. 2. A separated liquid 12 is nitrified and denitrified by a biological treating stage 3 using packed beds of aerobic immobilizing microorganisms. Ozone 4 is added to the excess sludge 15 of this biological treating stage 3 and the sludge is returned 16 to the pre-stage of the denitrifying stage. The dehydrated cake 11 of the flocculated and separated sludge is mixed with org. waste 18, such as municipal refuse, and after the mixture is thermally cracked and gasified by a fluidized bed gasifying furnace 6, the flying ashes from this fluidized bed furnace 6 are melted and separated 19. The fluidized bed gasifying furnace 6 allows the utilization of the grit 9 discharged from a sewage settling basin as a fluid medium by supplying this grit together with the dehydrated sludge and the waste, such as municipal refuse, to the fluidized bed gasifying furnace. |
