| 摘要 |
<p>PROBLEM TO BE SOLVED: To improve the dehydration properties of excess sludge and the separation/condensation properties of sludge and to reduce the consumption of a flocculant by introducing a substance containing an organic fibrous material into a precipitation basin in the first step when sewage, industrial wastewater, etc., are treated. SOLUTION: In an apparatus for treating wastewater, a substance 10 containing an organic fibrous material such as used paper is introduced into a precipitation basin 11 to be decomposed physically and/or biologically. Next, supplied wastewater 1 is introduced into an anaerobic tank 9 by way of the basin 11. The fibrous material degraded into a low molecular weight material in the basin 11 and part of the fibrous material crushed into pieces are introduced with discharged water into the tank 9. Part of sludge from a precipitation basin 7 is introduced into the anaerobic tank 9 as return sludge 13. In the tank 9, a reaction progresses anaerobically, and the discharged liquid of the tank 9 is introduced with circulating liquid 3, part of discharged liquid from an aerobic tank 4, into oxygen-free tank 2.</p> |
