We focus here on virus transport that, in the literature are treated either as solutes or as colloids, with sophisticated approaches including a three-phase system (immobile solid, aqueous, and colloidal phases). Viruses can absorb to larger natural colloids and compete for the sites with dissolved substances, but nobody has yet explored the impact of considerin their duality colloid/particle, that may explain the large distances traveled by some viruses under specific geochemical setups.
We will include here concepts such as aggregation of colloids, formation of self-colloids, and transport in a multicontinuum porous media, thus introducing new terms in the traditional virus transport equations.
The solution of the newequations will help explaining why (and when and how) wells or springs that are pathogen-free show a sudden outbreak. Solutions will be sought using fully meshless Lagrangian methods, as this framework allows dealing with the intrinsic natural heterogeneity of porous media and a variety of complex transport processes. These methods simulate solute transport by tracking in time a large number of particles injected into the system that interact between themselves and with the media.
The state, position, and mass of the particles are changed according to predefined relationships representing the actual processes occurring at different scales. This methodology avoids numerical difficulties such as numerical dispersion and oscillations. Multivariate statistics will be used to synthetically create geological images of aquifers including preferential pathways that concentrate flow and drive virus (and in general pollutant) migration, and recognized as crucial to characterize risk events.