Transport and filtration of aggregate particles in a porous media

The transport of colloidal suspensions in confined environments like the pores of filters and soils often leads to the formation of partial or complete clogging. Depending on the particle size D and the channel width W, the pore is blocked by sieving a large particle, by formation of an arch or by progressive accumulation. However, even though the suspension used to determine the type of clogging are rather monodisperse, it turns out that aggregates present in minute quantities are mainly responsible of the clog formation, their rotation dynamics near the pore surface enhancing their deposition compared to spherical particles. Here, we study the impact of these aggregates on the clogging of interconnected pores within a porous medium. We develop an in-situ particle characterization and a clog detection which enable us determining both the type of particles that are captured and the temporal clogging dynamics of adjacent pores. We show that aggregates are mainly captured near the pore entrance and their deposition are enhances by the pore cross talk. These conclusions underline the importance of particle composition and concentration of the suspensions to filter. It also opens up interesting perspectives in the design of new filters in which pore clogging is delayed.