| 摘要 |
PURPOSE:To sharply cut the amount of a sludge and markedly downsize an apparatus and process for dehydrating the sludge and incinerating the dehydrated sludge by adding a macromolecular flocculant to night soil type sewage to obtain a flocculating setting sludge and a flocculating supernatant liquid, fermenting the sludge with methane and then causing the so fermented sludge to permeate a film for separation, followed by subjecting a film permeating water and the flocculating supernatant liquid to a biological nitrification denitrification treatment. CONSTITUTION:A macromolecular flocculant 2 is added to a night soil 1 which is separated into a flocculating supernatant liquid 4 and a flocculating setting sludge 5 in a flocculation separation process 3. The flocculating setting sludge 5 is supplied to a methane fermentation tank 6 to digest organic substances anaerobically and finally convert them into a digestive gas 18 comprising CH4 and CO2 as the essential component. The flocculating supernatant liquid 4 and a water 9 which is obtained by causing an effluent of the methane fermentation treatment to permeate a film are supplied to a non-diluting type biological nitrification & denitrification process 11 wherein factors responsible for BOD, T-N and the like are biologically decomposed in a high concentration of active sludge. A discharged active sludge slurry 12 is supplied to an ultrafiltration film 13 to separate a residual sludge 14 from a filtrate water 15. The so separated residual sludge 14 is resupplied to the nitrification & denitrification process 11. |
