Sedimentation Behavior of Dispersions Composed of Large and Small Charged Colloidal Particles: Development of New Technology to Improve the Visibility of Small Lakes and Ponds

Abstract

Abstract In this study, we treat the dirty (small) and the adsorbing (large) particles, which are both of approximately micron-order or smaller, as charged and oppositely charged spheres and investigate the behavior of these particles under the gravity field by means of Brownian dynamics simulations. We have here mainly discussed the dependence of the adsorption rate on the particle diameter ratio, the volumetric fraction of large particles, and the input amount of large particles. Large particles adsorb much more small particles, per large particle, but the total number of small particles adsorbed by the large particles more significantly increases for large particles with smaller diameter if the same input amount of adsorbing agents (large particles) is used. This is because large particles with small diameter more actively perform random motion and move more extensively to adsorb small particles, although the surface area of large particles increases with decreasing diameter, leading to more opportunit...