Relating non-equilibrium solute transport and porous media physical characteristics

Breakthrough data for solute tracer transport at different velocities, covering a wide range of particle sizes and particle shapes corresponding to 324 breakthrough curves, were used in this study. Analysis was carried out for three granular porous media: crushed granite, gravel, and Leca® (a commercial insulation material). Mobile-immobile phase (MIM) solute transport parameters (dispersivity, mass transfer, and mobile (active) porosity) for non-equilibrium mass transport were determined for each breakthrough curve by fitting a MIM solute transport model to the breakthrough data. The resulting set of solute transport parameters was correlated with porous medium physical properties (particle size distribution and particle shape) to establish a set of simple expressions for estimating the MIM solute transport parameters. Linear expressions for predicting the solute dispersivity, mass transfer, and mobile phase porosity from porous medium particle size distribution (mean particle diameter and width of particle size distribution) and particle shape were developed based on regression analysis. A partial validation of these expressions indicated that the developed expressions are able to accurately predict solute transport parameters from porous medium physical properties.