(1) According to the flow state of the mixed liquid in the aeration tank, it can be divided into three types: push flow type, complete mixing type and circulating mixing type;
(2) According to the aeration mode, it can be divided into blast aeration tank, mechanical aeration tank and mechanical blast aeration tank used in combination with the two;
(3) According to the shape of the aeration tank, it can be divided into four types: rectangular corridor, round, square and annular runway;
(4) According to the relationship between the aeration tank and the secondary sedimentation tank, it can be divided into two types: joint construction (i.e., aeration sedimentation tank) and separate construction.