Catalytic hydrogenation of aqueous nitrate solutions in fixed-bed reactors

摘要: Abstract Liquid-phase hydrogenation using a solid Pd–Cu bimetallic catalyst offers promising technique for the removal of nitrates from contaminated drinking water. In this study, catalytic nitrate reduction was investigated in isothermal fixed-bed reactors at T  = 298 K and atmospheric pressure. Experiments carried out bubble-column reactor presence distilled water as reaction medium, demonstrate that can be efficiently removed liquid-phase, maximum contaminant level ammonium ions is not exceeded. The measured conversions are considerably influenced by variation volumetric flow rate either gas- or liquid-phase. order magnitude analysis apparent constant mass transfer coefficients confirms observed governed hydrogen into bulk Due to shorter mean residence times, lower trickle-bed reactor. At given conditions, particles were directly exposed gas-phase system, which drastically enhanced ammonia production. When used medium instead water, disappearance well selectivity decrease appreciably, attributed dissolved ionic species. Additionally, traces nitrites detected effluent.