Patent ID: 8110109

Claim:
A method for removing nitrogen from water comprising: predetermining a high and a low threshold value for nitrate concentration in water; predetermining a high and a low threshold value for ammoniac concentration in water; measuring the nitrate concentration in the water; activating a continuous aeration mode if the nitrate concentration reaches the predetermined low threshold value for the nitrate concentration, wherein the continuous aeration mode comprises: aerating the water such that nitrification and denitrification reactions occur simultaneously in the water; activating a sequential aeration mode if the nitrate concentration reaches the predetermined high threshold value for the nitrate concentration, wherein in the sequential aeration mode comprises: measuring the ammoniac concentration in the water; stopping aeration when the ammoniac concentration reaches the predetermined low threshold value for the ammoniac concentration; initiating aeration when the ammoniac concentration reaches the predetermined high threshold high for the ammoniac concentration; and maintaining the sequential aeration mode until the nitrate concentration reaches the predetermined low threshold value for the nitrate concentration and then activating the continuous aeration mode.