Mineralogical Characteristics of Aerosols Collected at Matsue and Kanazawa with a Special Reference to Neutralizing Effect on Acid Pollutants

A high-volume air sampler was used for aerosol sampling in
Matsue(Oct. 1992 to Mar. 1994) and Kanazawa(Mar. 27 to Apr.3,
1994). Snow and rain samples werecollected during 1993 to 1995 in
Kanazawa. The mineral compositions in aerosols during one year period
from October, 1992 to September, 1993 were analyzed by scanning
electron microscope-energy dispersive X-ray analyzer and X-ray powder
diffractometer. Major particles were grouped into aerosol types
:crustal minerals(48-68%), fly ash(9-17%), sulfur constituents(4-26%),
sea salt(0-3%),biological(1-5%)and miscellaneous
particles(3-6%). About 80% of fly ashes had Al and Si as major
compositions. Calcite and clay minerals were often closely associated
with submicrometer S-rich particles, suggesting that they acted as
carriers of surfur pollutants and played an important role in the
cycle of S constituents during transport. The experiment of reaction
between aerosols and simulated acid rain solutions showed that aerosol
with high Kosa flux had a relatively large neutralizing
ability.Calcite in aerosol played an important role in neutralization
of acids in the solutions. The results indicated that acid rain is
depended not only on the sulfate ion concentration in the
atmosphere,but also upon other factors such as the presence of some
materials available for neutralizing acids such as clay minerals and
calcite.