Fluid flow and colloid transport experiment in single-porosity sample; tracking of colloid transport behavior in a saturated micromodel

Release of colloids and their subsequent transport into the subsurface environments takes place during a wide range applications such as industrial, energy storage, agricultural activities. Therefore, processes contributing to transport, attachment, re-mobilization in porous media are attracting attention. A fraction released may cross soil vadose zone reach saturated groundwater. In this study, we explored colloid micromodel with high repulsion barrier where retention is assumed be low. Three major shortcomings were improved: pore space domain size, imaging resolution, speed imaging. The flow path 1357 size 4 µm tracked these enabled precise determination individual mechanism well integrated behavior system. Our direct observations have shown that even under unfavorable attachment conditions (defined based on DLVO theory) deposition occurred which was mainly due local velocity fluctuations grain surface heterogeneity. Using information from collective trajectories, quantified contribution differently behaved observed breakthrough curve show an integrated, macroscopic, system often only available when performing column or field scale experiments explore media. Furthermore, remobilization increased dispersion coefficient, consequently dispersivity value