Concentric circle type sewage treatment device

The concentric circle type sewage treatment device comprises an anaerobic tank, an anoxic tank, an aerobic tank, a sedimentation tank, a water inlet assembly communicated with the anaerobic tank, a water outlet assembly communicated with the upper part of the sedimentation tank, and a sludge discharge pipe arranged at the bottom of the sedimentation tank in a closable manner, which are coaxially arranged in sequence from inside to outside, the upper parts of the tank walls of the anaerobic tank, the anoxic tank, the aerobic tank and the sedimentation tank are respectively provided with water passing holes which are communicated with one another, sewage sequentially passes through the anaerobic tank, the anoxic tank, the aerobic tank and the sedimentation tank through the water inlet assembly, the water outlet assembly is used for discharging treated purified water, and the sludge discharge pipe is used for discharging sludge in the sewage. According to the utility model, the anaerobic tank, the anoxic tank, t