Characterization of Ion Components in Atmospheric Aerosol in Tokyo District

Hiroki KAMATAKI*†, Tetsuhito KOMEIJI and Masaaki YAMADA

Tokyo Metropolitan Institute of Environmental Protection; 7-5, Shinsuna 1-chome, Koto-ku, Tokyo 136-0075 Japan
Department of Technological Chemistry, Graduate Course of Engineering, Tokyo Metropolitan University; 1-1 Minamiohsawa, Hachiouji-shi 192-0397 Japan

To make clear trend and chemical components formation mechanism of aerosol in urban area, aerosol sampling and experiment was carried out at 5 sites in Tokyo for 5 years.
Sampling was for 24 hours (72 hours at mountain site) once a month from May 1993 to March 1997, by using high volume air sampler.
TSP concentration was measured by weigh method and sampling solution extracted from TSP was analyzed to obtain pH, EC, cations and anions.
Variation of TSP concentration was changed larger after November 1995 than before at several sites.
TSP concentration in urban area is 2.4 times higher than in mountain area, while [H+] concentration in suburb and mountain area were higher tendency than in urban area.
EC value was high correlative with amount of several ions concentration.
It is appeared that counter ion to retain H+ cation is corresponded to SO4 2−anion, because of retaining experiment with quartz filter and high correlation between H+ and SO42−.
Moreover, [SO42−] concentration in urban area is higher than in mountain area, it was inferable that H2SO4 concentration before neutralization was also high level in urban area.

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