Upscaling solute transport in porous media in the presence of an irreversible bimolecular reaction

► Continuum-scale modeling of homogeneous reactive transport has been questioned. ► A transient closure is needed to upscale advection-dominated reactive transport. ► Upscaled dispersive fluxes are intimately linked with the chemistry of the problem. ► Effective dispersion based on tracer data may not be suited to reactive transport. ► Adopting time-varying effective reaction rates is consistent with upscaling theory.