Abstract
Samples of water and suspended solids (SS) collected from the Hinuma river system over one year were analyzed by PIXE (Particle Induced X-ray Emission) to determine elemental concentrations.
The average SS concentrations at the 11 sampling sites ranged from 1.4 to 12.7mg·l-1 during ordinary water discharge. The SS concentrations were the highest in the upstream reaches of the Hinuma River, but were lower from the middle to downstream reaches, suggesting that the SS may have settled to the riverbed. All of the SS samples contained relatively high concentrations of Al, Fe, Ca, K and Mg, suggesting that the SS consist of particles from the earth's crust. Variations in elemental ratios to Al of Na, Mg, K, Ca and Cu in the SS among the sampling sites may have been due to differences in geology, land use, drainage from quarries, or brackishness of the water. Moreover the highest Fe: Al ratio was observed at a site where a large microbial mat had developed; the Cu: Al ratio was remarkably high at another site where intensive pig farming was practiced.
