Vapor–and Liquid–Phase Reactions between Nitrogen Dioxide and Water

Knowledge of the mechanisms involved in the aqueous absorption of nitrogen oxides is limited, and no definite evidence has been available to indicate if the major chemical reactions involved occur in the gas phase or in the liquid phase. This work was undertaken to determine in which phases the chemical reactions occur and to obtain additional information on the over-all mechanism of the removal process. The results of this investigation show that the rate of absorption of nitrogen oxides decreases significantly as the operating temperature is increased. The major portion of the chemical reactions occurs in the liquid film and the gas film, with an appreciable amount of the reactions occurring in each.