| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a membrane separation type oxidation ditch constituted so as to adjust the inflow of oxygen dissolved by air diffusion for washing a membrane to the water channel of an oxidation ditch to accelerate nitrification and denitrification to remove nitrogen in sewage. SOLUTION: A filter water tank 3 having a sludge mixed liquid intake port 31 and a discharge port 33 is arranged in the circulating water channel 12 of the oxidation ditch 1 so as to provide at least a predetermined space with respect to the sidewalls of the water channel, and an immersion type separation membrane 20 and an air diffusion pipe 23 for washing the membrane are arranged in the filter water tank 3.</p> |
