Effects of Ionic Strength on Fine Particle Clogging of Soil Filters

Abstract

The effects of ionic strength of the permeating fluid on the clogging of soil filters and drainage layers are addressed using both experimental and modeling investigations. In the experimental phase, a sandy soil representative of soil filters was permeated with pore fluids containing kaolinite particles. The ionic strength of the solutions was changed using different concentrations of NaOH and KCl. The permeability reductions of the soil filter were determined by varying pore fluid and particle suspension parameters. Higher ionic strength caused more flocculation of the kaolinite particles and resulted in more rapid reduction of permeability. In the modeling phase, a physical clogging model developed previously by the authors, was used to account for the ionic strength effects. A lumped parameter