Straight-line sewage treatment system for enhanced treatment of low C/N domestic sewage

A straight-line sewage treatment system for enhanced treatment of domestic sewage, comprising a sewage intake tank (1), wherein the sewage intake tank (1) is in communication with an enhanced denitrification tank (3) through a pipeline, an effluent outlet of the enhanced denitrification tank (3) is in communication with an effluent pipe (4), a first storage tank (5) is arranged below the effluent pipe (4), the effluent from the enhanced denitrification tank (3) flows into the first storage tank (5) through the effluent pipe (4), the first storage tank (5) is in communication with an enhanced phosphorus removal tank (6) through a pipeline, the enhanced phosphorus removal tank (6) is in communication with a second storage tank (7) through a pipeline, and the second storage tank (7) is in communication with a disinfection tank (8) and the sewage intake tank (1) through pipelines respectively;

• wherein a rotary sealing cover (3-1) is arranged at the top of the enhanced denitrification tank (3), a molecular polymer introduction layer (3-2) and a first water collecting layer (3-3) are arranged in sequence from top to bottom in the enhanced denitrification tank (3), and the molecular polymer introduction layer (3-2) is filled with a molecular polycaprolactone polymer.