Feasibility of Using Industrial Anion Exchange Resin to Remove Nitrate from Tile Water.

Presence of nitrate in tile water is one of the major environmental challenges facing Midwestern agriculture. This project evaluated the feasibility of using industrial anion exchange resin to remove nitrate from tile water. The resin is commonly used by water works departments and can be repeatedly recharged with solution containing chloride anions. Laboratory leaching of 100 mg L-1 nitrate solution through the 50 mL resin column showed retention of 13.3 g of nitrate per kilogram of the resin. Breakthrough curve showed center of the mass appearing at 310 pore volume with a partitioning coefficient of 141; a nearly instantaneous retention. After nitrate leaching, the resin was recharged with sodium chloride (NaCl) solution and the waste water containing sodium nitrate was incubated with wood chips to denitrify nitrate. Further studies are underway to assess (1) the use of potash solution as a recharging agent, thus recycling waste water as a KNO3 fertilizer, and (2) the frequency with which to recharge resin under field conditions.