Characteristics of Acid Precipitation in Kanazawa City

At the same time the rain, snow, hail and dust in atmosphere were sampled and concurrently were observed and analyzed by using an X-ray powder diffractometer, scanning electron microscope-energy dispersion diffractometer, and transmission type electron microscope. In general, the concentration of nitrogen dioxide is higher in the cities than that in mountainous region and the river catchment area, and therefore it is influenced by a topography and wind direction.

At an initial stage of rainfall, pH is low and a lot of acid precipitation is observed. In the dust sampled in the atmosphere of tunnel and cities, by using an X-ray powder diffractometer, the quartz, feldspar, clay mineral, gypsum and so forth were recognized. Based on an observation through the electron microscope, the sulphur constituents cover a surface of mineral grain and pollen, and moreover its microshape presents thin film shape or particle shape, and furthermore frequently is agglomerated.