title: Optimization of the cathode material for nitrate removal by a paired electrolysis process.
abstract: Ni, Cu, Cu(90)Ni(10) and Cu(70)Ni(30) were evaluated as cathode materials for the conversion of nitrate to nitrogen by a paired electrolysis process using an undivided flow-through electrolyzer. Firstly, corrosion measurements revealed that Ni and Cu(70)Ni(30) electrodes have a much better corrosion resistance than Cu and Cu(90)Ni(10) in the presence of chloride, nitrate and ammonia. Secondly, nitrate electroreduction experiments showed that the cupro-nickel electrodes are the most efficient for reducing nitrate to ammonia with a selectivity of 100%. Finally, paired electrolysis experiments confirmed the efficiency of Cu(70)Ni(30) and Cu(90)Ni(10) cathodes for the conversion of nitrate to nitrogen. During a typical electrolysis, the concentration of nitrate varied from 620ppm to less than 50ppm NO(3)(-) with an N(2) selectivity of 100% and a mean energy consumption of 20kWh/kg NO(3)(-) (compared to ∼35 and ∼220kWh/kg NO(3)(-) with Cu and Ni cathodes, respectively).
authors.affiliation: INRS Energie, Matériaux et Télécommunications, 1650 bd. Lionel-Boulet, Varennes (QC), J3X 1S2, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Reyter
authors.forename: Daniel
authors.initials: D
authors.lastname: Bélanger
authors.forename: Lionel
authors.initials: L
authors.lastname: Roué
mesh_terms: D003300:Copper / Q000737:chemistry; D003343:Corrosion; D004566:Electrodes; D004572:Electrolysis / Q000379:methods*; D009532:Nickel / Q000737:chemistry; D009566:Nitrates / Q000302:isolation & purification*
chemical_list: D009566:Nitrates; D003300:Copper; D009532:Nickel