Improved device for selectively separating aerobic granular sludge by using double-zone sedimentation tank

The utility model discloses an improved device for selectively separating aerobic granular sludge by using a double-area sedimentation tank. The device comprises a first sedimentation tank, a second sedimentation tank and a third sedimentation tank, the second sedimentation tank is arranged in the middle inside the first sedimentation tank; the water inlet structure is used for feeding water into the first sedimentation tank; the water outlet structure is arranged above the second sedimentation tank and is used for discharging water; the first sludge outlet structure and the second sludge outlet structure are respectively connected with the first sedimentation tank and the second sedimentation tank and are respectively used for discharging the first sludge in the first sedimentation tank and the second sludge in the second sedimentation tank; the device is provided with the first sedimentation tank and the second sedimentation tank, double-area sedimentation is formed, a water inlet structure and a water outl