Annular aeration coagulation device suitable for treating micro-polluted water

The invention discloses an annular aeration coagulation device suitable for treating micro-polluted water. The annular aeration coagulation device comprises a sludge backflow device, a stirring aeration device, a gas generation device and a coagulating basin; a water inlet pipe is arranged at the closed end of the coagulating basin; the stirring aeration device is arranged at the closed end of thecoagulating basin; the gas generating device is arranged on the outer wall of the coagulating basin; the sludge backflow device comprises a dross tank, a dross backflow branch pipe, a sludge collecting tank, a sludge backflow branch pipe, a backflow main pipe and a sludge screw pump; the dross tank and the sludge collecting tank are sequentially arranged at the open end of the coagulating basin,the sludge backflow branch pipe is communicated with the sludge collecting tank, the dross backflow branch pipe is communicated with the dross tank, the sludge backflow branch pipe and the dross backflow branch pipe are both c