Experimental investigation and modeling of particulate transportation and deposition in vertical and horizontal flows

Saturated soil column experiments were conducted to determine the influences of flow direction, flow rate, and particle-size distribution characteristics on the transport and deposition of particles in saturated porous media. Two bimodal-distribution particles and one unimodal-distribution particle were employed in these studies, and soil column experiments were performed using a variety of particle-size distributions and flow conditions. In addition, a modified convection–dispersion model for particle transport and deposition was developed, considering dispersive flux on the deposition kinetics. The experimental breakthrough curves fit well with the analytical solution of the modified convection–dispersion model. Regardless of particle-size distribution, the particles’ mean velocity increases linearly with the mean interstitial fluid velocity. The particles’ mean velocity in horizontal flow is lower than that in vertical flow. Furthermore, dispersivity decreases with increasing flow rate in vertical flow. The range of the particles’ dispersivity in vertical flow is larger than that in horizontal flow. Finally, the rate of particle deposition increases with particle size. Overall, this study highlights the complicated interdependence of the effects of flow rate, flow direction, and particle-size distribution on particulate transportation and deposition.