Deposition and re-entrainment of model colloids in saturated consolidated porous media: Experimental study

Deposition and release of negatively charged colloidal latex particles in consolidated porous media were experimentally investigated. Special attention was paid to particle release due to physicochemical perturbations. Experimental data are presented in terms of breakthrough curves and interpreted through the particle–collector interaction potential profiles, calculated using the Born-DLVO theory. A phenomenological model is proposed to predict particle release assessing that most of mobilized colloids are those previously deposited in secondary minimum. It is shown that particle release is quantitatively reversible but the colloid–collector binding energy may change. This was assessed by performing successive deposition–release cycles that show a continuous decrease of the amount of mobilized particles from one cycle to another. At the end of the last cycle, no particle release was detected suggesting that the binding energy changes from one cycle to the following one.

A correlation between the experimental values of the fraction of mobilized colloids, FMC, and the detachment efficiency, β, has been established applying a Maxwell speed distribution model.Figure optionsDownload as PowerPoint slide