Electrochemical reduction of nitrate using various anodes and a Cu/Zn cathode

Electrochemical reduction of nitrate was studied using a Cu/Zn cathode and Ti/Pt, Ti/IrO2–Pt and Ti/RuO2–Pt anodes in an undivided and unbuffered cell. A novel condition for performing both cathodic reduction of nitrate and anodic oxidation of the ammonia and nitrite by-products was achieved using Ti/Pt and Ti/IrO2–Pt anodes in the presence of NaCl, especially with Ti/IrO2–Pt anode. Nitrate could be completely removed using the Ti/IrO2–Pt and Ti/Pt anode, with neither ammonia nor nitrite detected in the treated solution. A low nitrate reduction rate was observed when using a Ti/RuO2–Pt anode in the presence of NaCl. However, in the absence of NaCl, all anodes showed good performance for nitrate reduction, with the Ti/Pt anode having the highest selectivity for reducing nitrate to nitrogen.