LAUSR

Abstract An elimination process of gaseous nitric oxide (NO) by new Fenton process based on synergistic catalysis of Cu2+ and Fe2+ (i.e., Cu2+/Fe2+-catalytic Fenton wet scrubbing process) was developed. In a bubbling scrubber, experimental works were implemented to evaluate the influence of several principal technological parameters on gaseous NO elimination. Elimination mechanisms and paths of gaseous NO by Cu2+/Fe2+-catalytic Fenton wet scrubbing process were also elucidated. The experimental results showed that NO elimination was obviously strengthened after adding Cu2+ into original Fenton oxidative process. The synergistic role produced by Cu2+ and Fe2+ in Cu2+/Fe2+-catalytic Fenton wet scrubbing process contributed to more hydroxyl radicals, which led to a synergistic enhancement for NO elimination. NO elimination was elevated when concentration of Cu2+, Fe2+ or H2O2 (in the range of low concentration) increased, while was reduced by the raise of reacting temperature, and concentrations of NO and SO2, but was not almost affected by concentration of CO2 and O2. Reagent pH and concentrations of CO32− and HCO3− exhibited different impacts on NO elimination in different ranges. Gaseous NO was eliminated through four paths: (1) the synergistic role between Cu2+ and Fe2+ in Cu2+/Fe2+-catalytic Fenton wet scrubbing process inducing more OH to oxidize NO; (2) the original Fenton oxidative process producing OH to oxidize NO; (3) the Cu2+/H2O2 process forming OH to oxidize NO; (4) the H2O2 directly oxidizing NO. The dominance of paths follows the following order: path (2) > path (1) > path (3) > path (4).