The application of a zero gap solid polymer electrolyte (ZGSPE) reactor to deminealise nitrate ions in aqueous wastewater is described. The following performance data for the reduction of a simulated alkaline solution with 16.1 mM nitrate ions under galvanostatic operation were achieved: percentage of nitrate removal up to 100%, rates of nitrate removal up to 0.057 mol cm(-2) h(-1), space-time yields up to 5.4 kg m(-3) h(-1), current efficiencies up to 24.5% and energy consumption between 40.1 and 63.3 kW h kg(-1). The beneficial effects of higher temperatures and nitrate ion concentrations and using a suitable electrolyte flow rate on the activity, selectivity and efficiency is reported. PdRh1.5/Ti mini-mesh electrode used in the study was stable after a cumulative use of 1000 h.