The deep denitrification V-type filter is used to reduce TN, while the small-size filter material can effectively intercept suspended solids. Coagulants can also be added at the front end to remove phosphorus simultaneously, achieving the simultaneous removal of TP, TN, and SS. When the carbon source is properly added, the effluent TN can be ≤5mg/L, or even ≤3mg/L.
