Abstract
Conversion of NOx to NO2- on filters was investigated by using NaOH (NaCl) impregnated on filter, NaCl aerosol (H2O vapor) generated by nebulizer and 6.22-600ppm (v/v) NOx, to estimate the amount of particulate NO2- formation in the atmosphere.
By the reaction of NO2 with NaOH, particulate NO2- concentration formed (and/or collected) on filters was increased with a increase in both NO2- and NaCl-concentration, and the NO3--N/NO2--N ratio was decreased with a increase in NaOH concentration, but the ratio less than 1 was scarcely obtained.
By the reaction of NO2-NO-H2O-air mixture with NaCl, the amount of NO2--formation depended mainly on H2O and NaCl, as well as NOx and other experimental conditions, but thatof NO3- was almost constant, and the ratio of NO2--N/NO3--N formed under these conditions was about 1%.
Additional production of NO2- resulting from absorption of gaseous NO2 on particulate NO2- was not observed.
