Solute transport in heterogeneous model porous media under different flow rates: Experimental and modelling study

The present paper focuses on solute transport behaviour in a Model Heterogeneous Porous Medium (MHPM) under different flow rates. We report tracer experiments stationary hydraulic conditions, with 7 rates spanning two orders of magnitude. Several replicates are carried out several MHPMs, allowing for sound statistical assessment experimental imprecision. BreakThrough Curves (BTCs) exhibit dual mode agreement previously-reported field scale experiments. This is shown to be flow-rate independent suitable variable change, the BTCs superposing limit uncertainty. experiment modelled using classical Multi-Region Advection-Dispersion (MRAD) model only mobile regions. rate reformulation MRAD that allows both water and continuity preserved during calibration process. Assuming linear dependence dispersion exchange coefficients yield satisfactory behaviour. confirms linearity coefficient respect rate, often suggested literature, over wide range conditions.