Sewage treating appliance

The utility model discloses an appliance for improving sewage treating effect by using a biochemical technique. A cuboid pool consists of an oxygen-poor reaction chamber, a filtering clarifying chamber and an aerobic reaction chamber which are adjacent in sequence, wherein the longitudinal section of the filtering clarifying chamber is trapezoidal; the oxygen-poor reaction chamber is communicated with the aerobic reaction chamber through a channel between the oxygen-poor reaction chamber and the aerobic reaction chamber; a sludge inlet is formed below a second interface of the filtering clarifying chamber; and a sludge backflow pipe opening to the oxygen-poor reaction chamber is arranged in the bottom of a first interface of the filtering clarifying chamber. In the filtering clarifying chamber, clear water flows out through an upper clear water overflow weir, so that the sewage purifying process is finished; and adsorbed and deposited active sludge flows back into the oxygen-poor reaction chamber for a new cy