Abstract
Water-saturated column experiment was conducted to investigate the filtration of polystyrene latex (PSL) particles through the columns packed with glass beads and Kanuma Soil from the aspects of surface charge properties of colloidal particles and grains. Zeta potential of PSL particles was measured by microelectrophoresis measurement and that of grains was determined by streaming potential technique. It was confirmed that PSL particles and glass beads are negatively charged and each absolute value increases with decreasing NaCl concentration. In contrast, zeta potential of Kanuma Soil was found to be almost zero despite NaCl concentration change between 10-4 M and 0.05 M. These results are corresponding to the result that Kanuma Soil trapped PSL particles more than glass beads in the column experiment. Namely, low zeta potential leads to achieving high filter efficiency of Kanuma Soil. Moreover, observing the surface shape of Kanuma Soil with scanning electron microscope, we confirmed that Kanuma Soil has the micro asperity that is the same scale of PSL particles. It can contribute to high performance of Kanuma Soil in filtration.
