Reactor for sewage treatment

A reactor for treating sewage, comprising:

• a) an inner layer comprising a water distribution zone;
• b) a middle layer comprising a biological aerated filter, the biological aerated filter comprising a wall and a bottom, the bottom of the biological aerated filter comprising a water outlet;
• and
• c) an outer layer comprising an artificial wetland, the artificial wetland comprising a bottom, the bottom of the artificial wetland comprising a water inlet;
• wherein:
• each of the water distribution zone, the biological aerated filter, and the artificial wetland is in a shape of a circle;
• the water distribution zone is adapted to receive the sewage via a water inlet pipe;
• the water distribution zone communicates with the biological aerated filter via a first overflow;
• the water outlet arranged on the bottom of the biological aerated filter is connected to the water inlet arranged on the bottom of the artificial wetland to allow the biological aerated filter to communicate with the artificial wetland;
• the water outlet of the artificial wetland is connected to a water outlet pipe;
• the biological aerated filter is formed by two layers of circular corridors and is provided with a plurality of filler frames and aerators;
• the biological aerated filter further comprises a first plurality of sections which are connected to one another, each of the first plurality of sections comprising a first anoxic zone and a first aerobic zone;
• the plurality of filler frames are arranged with a distance between one another, and a gap is disposed between each of the plurality of filler frames and the wall of the biological aerated filter;
• and
• the artificial wetland further comprises a second plurality of sections which are connected to one another, each of the second plurality of sections comprising a first isolation wall, a second isolation wall, a second anoxic zone, a natural reoxygenation zone, and a second aerobic zone;
• the first isolation wall is disposed between the second anoxic zone and the natural reoxygenation zone and separates the second anoxic zone from the natural reoxygenation zone;
• the second isolation wall is disposed between the second aerobic zone and the natural reoxygenation zone and separates the second aerobic zone from the natural reoxygenation zone;
• a second overflow is disposed on a top of the first isolation wall;
• a third overflow is disposed on a top of the second isolation wall;
• the second overflow is higher than the third overflow;
• and the natural reoxygenation zone is adapted to receive the sewage via the second overflow and to discharge the sewage to the second aerobic zone via the third overflow, wherein the sewage contacts air in the natural reoxygenation zone.