Special Session on:
Mixing and Reactions across Scales in Porous Media


Marco Dentz, Institute of Environmental Assessment and Water Research (IDAEA), Spanish National Research Council (CSIC), Barcelona, Spain
Diogo Bolster, Notre Dame University


Porous media exhibit physical and chemical heterogeneities on multiple scales ranging from the pore to reservoir scale. In general, mixing and chemical reactions are well understood for situations that are characterized by temporal and spatial scales over which local scale physical equilibrium holds so that the support volume can be considered equivalent to a well-mixed reactor. In such idealized situations reactive transport can be modeled by the advection-dispersion equation combined with source terms and boundary conditions to account for chemical reactions. Typically in practice, at hydrologically relevant temporal and spatial scales, such local equilibrium conditions are not fulfilled and the observed reaction and mixing dynamics cannot be explained by a local scale reactive transport approach adapted to the coarse grained support scale. Physical and chemical heterogeneity impact both large scale mixing and reaction. Lack of complete mixing can in turn lead to anomalous behaviors. The aim of this session is to discuss modeling and upscaling approaches to understand and quantify the diverse (anomalous) reaction and mixing phenomena observed in heterogeneous porous media. Key words for this session include: Eulerian and Lagrangian approaches for mixing quantification and reactive transport modeling, pore-scale models, multiscale models, multicontinuum approaches, stochastic-convective approaches, Lagrangian and Eulerian upscaling methods, hybrid models, PDF approaches for the quantification of concentration statistics, chaotic mixing, mixing models.