| Popis: |
Behavior of sulfate, nitrate and other secondary pollutants in the long-range transport of air pollution was investigated by a co-operative field observation. It was conducted during 26–30 July 1983 in the large area from the coastal region around Tokyo Bay to the mountainous region in Central Japan. Gaseous HNO 3 and particulate NO − 3 , SO 2− 4 and NH + 4 increased notably along the route of the polluted air mass. In the inland area, the ion balance in aerosol between SO 2− 4 , NO − 3 , Cl − , NH + 4 , Na + , K + , Ca 2+ and Mg 2+ was usually good. However, when the long-range transport over 150 km caused high concentration of oxidants (Ox) in this area, the ion balance leaned towards the anion side. From this, the existence of droplets of H 2 SO 4 or NH 4 HSO 4 was suggested. Gaseous HNO 3 was converted into the aerosol phase when the polluted air mass moved over the mountain pass and was transported into the mountainous region. The conversion was found to follow the equilibrium relationship between gaseous HNO 3 , NH 3 and NH 4 NO 3 which depends on the temperature and relative humidity (rh). Finally, the oxidation of NO x to HNO 3 or NO − 3 was found to proceed almost at the same time as the Ox generation, but the oxidation of SO 2 to SO 2− 4 proceeded more slowly. |
