| 摘要 |
PURPOSE:To eliminate incineration troubles by subjecting biologically treated water to a membrane sepn., permeating the membrane transmitted water through a reverse osmosis membrane to obtain the highly treated water and recycling this water as industrial water. CONSTITUTION:The sewage 1 of the night soil system is subjected to scum removal in a scum removing stage 2. The night soil 3 subjected to the scum removal is biologically treated in a biological denitrification treatment stage 5. The separated night soil 4 is sent to a sludge dehydrating stage 21. The activated sludge slurry 6 flowing out of the treatment stage 5 is completely separated of SS in a membrane sepn. stage 7 using an ultrafilter membrane to separated sludge 8 and the membrane permeated water 9. The greater part of the separated sludge 8 is circulated as return sludge 10 to the treatment stage 5. The membrane permeated water 9 is pumped into a permeation treatment stage using the reverse osmosis membrane, by which chromaticity components, org. nitrogen, etc., are removed at a high degree and the highly treated water 13 is obtd. |
