Patent ID: 7731842

Claim:
A wastewater treatment apparatus including a tank having a floor and defining an inlet for the introduction of wastewater and a nitrate rich water into the tank, said wastewater containing BOD to be removed therefrom, and an outlet for the discharge of treated wastewater from said tank, said tank having a fluid level defining a top surface of said wastewater within said tank, comprising: an anoxic chamber configured to have a vertical rise velocity of at least approximately 30 feet per hour, said anoxic chamber in flow communication with said inlet to receive said wastewater and said nitrate rich water, said anoxic chamber being divided into a plurality of reactor cells arranged in series to define alternating vertical flow paths through succeeding reactor cells from a first reactor cell in flow communication with said inlet, said wastewater and said nitrate rich water being mixed together within said first reactor cell, to a last reactor cell having a discharge of said treated wastewater therefrom, said alternating vertical flow paths defining a vertical serpentine flow path through said anoxic chamber.