Quantitative description of multi-component reactive transport in porous media: An empirical approach

We propose a general method for the description of multi-component reactive transport in porous media. The approach is based on the local equilibrium assumption and consists of four steps: (i) measurement of the adsorbed amounts of all components of interest by means of laboratory batch experiments, (ii) construction of a simple, empirical binding model consistent with the experimental data by means of constrained, regularized least-squares, (iii) calculations of multi-component breakthrough curves based on numerical solutions of the transport equations coupled to the empirical binding model, (iv) verification of these model predictions with laboratory column experiments. We demonstrate the applicability of the procedure by investigating simultaneous transport of cadmium and zinc at constant pH in a silica sand column.