| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a septic tank with a phosphorus removal device which has an excellent phosphorus removal function, can maintain the phosphorus removal function for a long time, and achieves excellent purification action and easy maintenance. <P>SOLUTION: The septic tank 2 has primary treatment tanks 20, 22 into which sewage is introduced, a biofiltration tank 24 into which the sewage treated by the primary treatment tanks is introduced, and a final treatment water tank 26 which temporarily stores liquid treated by the biofiltration tank. A phosphorus removal line 34 for returning a part of the treated liquid stored in the final treatment water tank 26 to the biofiltration tank 24 through a phosphorus removal device 40 installed separately from biofiltration tank 24, and a circulating line 32 for returning a part of the treated liquid stored in the water tank 26 to the primary treatment tanks 20, 22 without through the phosphorus removal device are installed in parallel. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
