Removal of nitrate by electrodialysis: effect of operation parameters

We investigated the effect of applied voltage and electrolyte concentration on the nitrate removal and its energy/current efficiency during the electrodialysis. The current increased as the applied voltage increased up to 30 V showing the limiting current density around 20 V. The nitrate removal efficiency (31 to 71% in 240 min) and energy consumption (11 to 77 W∙h/L) gradually increased as the applied voltage increased from 10 to 30 V. The highest current efficiency was obtained at 20 V. The increase in electrolyte concentration from 100 to 500 mM led to the dramatic increase of nitrate removal efficiency with much faster removal kinetics (100 % in 10 min).