Tuning sedimentation through surface charge and particle shape

This is a Preprint and has not been peer reviewed. The published version of this Preprint is available: https://doi.org/10.1029/2020GL091251. This is version 1 of this Preprint.


Download Preprint


ALI SEIPHOORI , Andrew Gunn , Sébastien Kosgodagan Acharige, Paulo Arratia, Douglas J Jerolmack 


Mud forms the foundation of many coastal and tidal environments. Clay suspensions carried downstream from rivers encounter saline waters, which encourages aggregation and sedimentation by reducing electrostatic repulsion among particles. We perform experiments to examine the effects of surface charge on both the rate and style of sedimentation, using kaolinite particles as a model mud suspension and silica spheres with equivalent hydrodynamic radius as a control. Classic hindered settling theory reasonably describes sedimentation rate for repulsive clay particles and silica spheres, which form a highly concentrated jamming front. The hindered settling description breaks down for attractive clay particles, which aggregate to form clay gels that consolidate like a soft solid. Water flow form fracture-like channels in the bulk of the gel, which disappear as gel enters a creep regime. Results may help toward understanding the effect of surface charge and particle shape on the sedimentation and erodibility of natural mud.




Engineering, Physical Sciences and Mathematics


Surface charge, Hindered settling, Collapse transition, Consolidation, Clay gels


Published: 2020-10-22 19:15


CC BY Attribution 4.0 International

Add a Comment

You must log in to post a comment.


There are no comments or no comments have been made public for this article.