Mobile subsurface colloids have received considerable attention because the migration of colloids and colloid-contaminant complexes through the porous matrix substantially increase the risk of groundwater pollution. Little information about mechanisms for colloid transport and colloid filtration in unsaturated porous media is readily available. In this poster we use a finite element program COMSOL Multiphysics® to investigate the transport of colloids around solid grains and air bubbles in a porous matrix. The COMSOL numerical code is validated against existing experimental measurements and numerical solutions of colloid deposition on a solid grain. The numerical simulation of the colloid movement around the bubble showed that more colloids collided with the bubble (a slip boundary) than with the solid grain (a no slip boundary). The slip boundary condition resulted in high pore water velocity around the bubble and large diffusive fluxes to the surface compared with the no slip condition where the low velocities hindered diffusion to the solid grain. By varying the flux, we show that pore water velocity has a substantial effect on the deposition and transport paths of the colloids. In addition we present results of unsaturated porous medium simulations on colloid transport and deposition with assemblages of solid grain and air bubble collectors.