Nitrogen sparging assisted anoxic biological water treatment system

A method for treating water containing dissolved nitrate and other oxidized inorganic contaminants amenable to biological conversion, the method comprising:

• feeding the water as influent into an anoxic contactor packed with media;
• feeding additives to the water to facilitate biological conversion of the dissolved nitrate and the other oxidized inorganic contaminants;
• introducing nitrogen gas through a diffuser positioned at a bottom of the anoxic contactor to sparge and remove dissolved oxygen from the water;
• establishing colonies of microorganisms to convert the dissolved nitrate to additional nitrogen gas within the anoxic contactor;
• introducing air or oxygen gas to the water in a reaeration unit;
• establishing colonies of microorganisms assimilating residual dissolved nitrate and consuming residual dissolved organic carbon within an aerobic filter or bed;
• removing particulates from the water via the aerobic filter or bed;
• and
• expelling an effluent from the aerobic filter or bed, the effluent including a lower nitrate concentration than the water fed into the anoxic contactor as the influent.