The removal of Nitrate-nitrogen from ground water by electrodialysis

In this study, the effects of applied voltage, solution pH and coexistence of other ions such as sulfate ion (SO42-) and chlorideion (Cl-) were investigated on the removal of nitrate-nitrogen (NO3--N) from ground water by electrodialysis. The examinedoperating conditions were evaluated for optimizing the removal efficiency of NO3--N. Real ground water samples taken from arural area of Yongin city and artificial ones with components similar to the real ground water were tested for the study, whichcontained NO3--N concentration of 17mg/L that exceeds current drinking water quality standard of 10 mg/L. The increase in theremoval rate of NO3--N was observed as the applied voltage increased from 5V to 30V, while no significant increase in theremoval rate appeared at the applied voltage beyond 20V during a given operating time. The removal rate appeared to getlower at both acidic and basic condition, compared to neutral pH. Coexistence of of SO42-and Cl-demanded much longeroperating time to achieve a given removal rate or to meet a certain level of treated water concentration. When nitrate ion wascombined with SO42-and Cl-, the removal rate was reduced by 4.29% and 10.83%, respectively.