Oxidation of aqueous sulfite ion by nitrogen dioxide

Abstract

The reaction of nitrogen dioxide with aqueous sulfite solutions, in the presence and in the absence of oxygen, has been studied using Raman spectroscopy to determine product concentrations. The products observed include nitrite, sulfate, and dithionate ions. The reaction appears to initially produce nitrite ion and sulfite radical: NO2 + S032" -* NO2-+ SO3•-. The sulfite radical can undergo either recombination or reaction with oxygen to form SO5•-. In the absence of oxygen, we obtain a ratio of [S042-]/[S2C>62-] = 1.8 ± 0.3, reflecting the branching of the recombination of sulfite radical: SO3-+ SO3•--* S2O62-or SO3•-+ S03--*• SO32-+ SO3. The production of S03-and SO5•-radicals from the nitrogen dioxidesulfite ion reaction suggests that this reaction could contribute significantly to S(IV) oxidation in atmospheric aerosols under suitable conditions.

An Observation-Based Model for Secondary Inorganic Aerosols

“…Laboratory experiments have established that the reaction is faster under higher pH conditions (Lee and Schwartz, 1983;Clifton et al, 1988;Littlejohn et al, 1993) and in the presence of O 2 (Littlejohn et al, 1993;Shen and Rochelle, 1998).…”

Technical Note: Quantification of interferences of wet chemical HONO LOPAP measurements under simulated polar conditions

“…The sampling conditions used for the LOPAP instrument also have the advantage that HONO is completely sampled at low pH, for which several known chemical interferences caused by, e.g. NO 2 and SO 2 (Littlejohn et al, 1993;Spindler et al, 2003), NO 2 and phenols (e.g. Alfassi et al, 1986;Coombes et al, 1994;Ammann et al, 2005), NO 2 +aromatic amines (Saltzman, 1954) or PAN hydrolysis (Frenzel et al, 2000) are minimised (Heland et al, 2001;Kleffmann et al, 2002Kleffmann et al, , 2006.…”

“…In addition, since the kinetics of most known interfering liquid phase reactions, i.e. PAN hydrolysis (Frenzel et al, 2000), NO 2 +SO 2 (Littlejohn et al, 1993;Spindler et al, 2003), NO 2 +phenols (Alfassi et al, 1986;Coombes et al, 1994;Ammann et al, 2005) or NO 2 +aromatic amines (Saltzman, 1954), increase with increasing pH, these chemical interferences are expected to be even more severe for instruments that collect air samples under neutral or even basic conditions (see for example, Spindler et al, 2003;Genfa et al, 2003). In contrast, in the LOPAP instrument very acidic sampling conditions are applied (pH=0).…”

Influence of Oxidizing Reactor on Flue Gas Denitrification by Ozonation and Possibility of by-Product Separation

“…In the earlier work (Głomba et al, 2016) it was demonstrated that ozonation of gas containing sulphur dioxide, promotes the conversion of sulphite to sulphate being absorbed in the alkaline solution although complete oxidation of sulphite required the ratio The agent is nitrogen dioxide, which accelerates oxidation of SO3 2-ions. Littlejohn et al (1993) suggest that NO2 acts catalytically in this process.…”