Solute transport of charged species in porous media is significantly affected by the electrochemical migration term resulting from the charge-induced interactions among the dissolved ions as well as with solid surfaces. Therefore, the characterization of such electrochemical processes is of utmost importance for assessing the fate and transport of charged solutes in porous media. This work presents a detailed investigation of the electrochemical effects during conservative and reactive multicomponent ionic transport in homogeneous and heterogeneous domains by means of laboratory bench-scale experiments and numerical simulations. The investigation aims at quantifying the key role of small-scale electrostatic interactions in flow-through systems, especially when advection is the dominant mass-transfer process. By performing a series of quasi two-dimensional flow-through experiments with different electrolyte solutions, we study the specific influence of charge effects on steady-state and transient transport of multicomponent ionic species in saturated porous media. The outcomes of steady-state experiments reveal that Coulombic cross-coupling of diffusive/dispersive fluxes significantly affects the lateral displacement of charged species not only in diffusion-dominated systems but also in advection-dominated flow regimes. We also show that these charge effects do not vanish during transport in spatially variable flow-fields in physically heterogeneous porous media. Furthermore, the electrostatic interactions were found to significantly impact the pH fronts propagation depending on the solution composition as well as on the concentration gradients of the other charged species in a multicomponent environment. Experiments were also performed under transient transport conditions. The results demonstrate that ionic interactions significantly influence the transient multicomponent ionic transport and lead to remarkable differences in solute breakthroughs and dilution behaviors of different ionic species. Each experiment has been quantitatively evaluated with numerical simulations. The experiments have been accompanied by stepwise model development in which a multicomponent ionic formulation, explicitly accounting for charge interactions, was adopted. A new two-dimensional multicomponent ionic transport model has been proposed. The modeling approach is based on the local charge balance, multicomponent formulation of diffusive/dispersive fluxes, and improved description of compound-specific hydrodynamic dispersion coefficients. The multicomponent ionic transport code was coupled with the widely used geochemical code PHREEQC (using IPhreeqc module) and, thus, provides a comprehensive framework to perform Darcy- to field-scale reactive transport simulations, explicitly considering electrochemical migration as well as geochemical calculations included in PHREEQC’s reaction package. Numerical simulations, performed with the newly proposed model, showed that electrostatic interactions among charged species affect conservative and reactive transport also in field-scale domains containing both physical and geochemical heterogeneities.