| 摘要 |
<p>PROBLEM TO BE SOLVED: To do high grade denitrification treatment simply by denitrifying primary treated water which was subjected to aerobic biological treatment by anaerobic bio-treatment using carbon fibers as a contact material. SOLUTION: At the start of drainage treatment, a kind of seed sludge is charged into an aeration tank 2 and conditioned while being circulated for a necessary period through the tank 2 and an anaerobic filter bed tank 4. As the result of conditioning, a microorganism phase corresponding to the properties of drainage is held in each tank, bio-oxidation is done by aerobic treatment, and SS and BOD components are removed. The biologically oxidized drainage (primary treated water) is subjected to solid-liquid separation in a sedimentation tank 3, the supernatant is led to the tank 4 using carbon fibers as a contact material and subjected to denitrification treatment (secondary treatment) by an anaerobic organism membrane formed on the carbon fibers, after being subjected to necessary after-treatment by an after-treatment apparatus 5, is discharged or reused. Part of the sludge from the tank 3 is returned to the tank 2 (suspended organism treatment tank) to keep intra-tank MLSS at a prescribed level.</p> |
