BDP sewage denitrogenation treatment system and method for sewage denitrogenation treatment

1. A Biological Double efficiency Process (BDP) sewage denitrogenation treatment system, comprising

a water inlet zone which is provided with a water inlet;

a first aerodynamic zone in communication with the water inlet zone;

a circumfluent zone in communication with the first aerodynamic zone;

a second aerodynamic zone in communication with the circumfluent zone;

a sedimentation zone which is in communication with the second aerodynamic zone and provided with a water outlet; and

a reflux buffering zone in communication with the sedimentation zone and the circumfluent zone; and

on the wall of the circumfluent zone there is provided a sludge exchange pipe via which the circumfluent zone exchanges sludge with a tank.

2. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that three adjacent side walls of the sedimentation zone share walls with the circumfluent zone, the reflux buffering zone and the second aerodynamic zone, respectively.

3. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that the circumfluent zone is an annular groove body, a square groove body, a rectangular groove body, a circular groove body or an elliptical groove body.

4. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that the bottom of the sedimentation zone is provided with a steady flow plate;

a gas flushing device, an inclined plate settler and an inclined tube settler are provided on the steady flow plate;

the gas flushing device is disposed spaced from the inclined plate settler; and

the inclined tube settler is disposed on the inclined plate settler.

5. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that the circumfluent zone is provided with an air blower;

the air blower stirs the sewage within the circumfluent zone via gas-pumping.

6. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that the water inlet zone and the first aerodynamic zone are provided within the circumfluent zone.

7. The BDP sewage denitrogenation treatment system according to claim 1 , characterized in that within the circumfluent zone there is provided a division wall along the longitudinal direction;

the water inlet zone and the first aerodynamic zone are provided between the division wall and the outer wall of the circumfluent zone.

8. A sewage denitrogenation treatment method, comprising the following steps:

the sewage to be treated is introduced into a sewage denitrogenation treatment system via a water inlet zone;

then sequentially treated through a first aerodynamic zone, a circumfluent zone, a second aerodynamic zone and a sedimentation zone, and the treated sewage is discharged via the sedimentation zone;

the sludge in the sedimentation zone flows back to the circumfluent zone via a reflux buffering zone;

the circumfluent zone exchanges sludge with a tank via a sludge exchange pipe.

9. The sewage denitrogenation treatment method according to claim 8 , characterized in that the particle size of the bacterial micelle in the sewage denitrogenation treatment system is 100 μm or less.

10. The sewage denitrogenation treatment method according to claim 8 , characterized in that the dissolved oxygen in the sewage denitrogenation treatment system discretely fluctuates within the range of 0.1 mg/L˜0.3 mg/L.

11. The sewage denitrogenation treatment method according to claim 8 , characterized in that the lateral flow rate of the water body in the sewage denitrogenation treatment system is 0.05 m/s˜0.2 m/s.