| 摘要 |
PROBLEM TO BE SOLVED: To provide a new treatment method synergistically enhancing the separation efficiency of a phosphorus component by combinedly using a biologically treatment technique and a chemical treatment technique. SOLUTION: A sewage treatment apparatus 10 is provided with a first biological treatment tank 16 to which org. sewage is transferred through a large-scale impurities removing tank 12 and a flow rate adjusting tank 14 and a second biological treatment tank 18 to which treated sewage is transferred. The first biological treatment tank 16 performs biological treatment for removing a phosphorus component by denitrifying bacteria and the bottom part thereof is intermittently aerated by a first aeration pipe 34. A phosphorus flocculant (Fe2 (SO4 )) is added to the first biological treatment tank 16 during non-aeration and the precipitation of phosphorus is also performed by this phosphorus flocculant. The second biological treatment tank 18 performs the biological treatment of the phosphorus component by denitrifying bacteria and aerated intermittently from the second aeration pipe 40 disposed in the bottom part of the treatment tank 18. At this time, the intermittent aeration in the first and second biological treatment tanks 16, 18 is performed so that one biological treatment tank is aerated and the other biological treatment tank is not aerated. |
