Denitrification tank

The utility model relates to a denitrification tank which comprises a tank body, an effluent weir arranged in the tank body, a water inlet pipe connected to the lower end of the tank body, a water outlet pipe arranged above the tank body and a treatment mechanism for treating sewage, the treatment mechanism comprises a filter plate fixed in an inner cavity of the tank body, a supporting layer arranged above the filter plate and a filter material layer arranged above the supporting layer, a plurality of water passing pipes are arranged on the filter plate in a penetrating manner, liquid at the upper end and the lower end of the filter plate is communicated through the water passing pipes, flow meters are arranged on the water passing pipes, and the flow meters are communicated with the filter material layer through the supporting layer. And the flow meter is electrically connected with a control background for sewage treatment. The flow meter is used for detecting the flow passing through the water passing pip