  In soft porous media, deformation drives solute transport via the intrinsic
coupling between flow of the fluid and rearrangement of the pore structure.
Solute transport driven by periodic loading, in particular, can be of great
relevance in applications ranging from the geomechanics of contaminants in the
subsurface to the biomechanics of nutrient transport in living tissues,
scaffolds for tissue engineering, and biomedically employed hydrogels. However,
the basic features of this process have not previously been systematically
investigated. Here, we fill this hole in the context of a 1D model problem. We
do so by expanding the results from a companion study, in which we explored the
poromechanics of periodic deformations, by introducing and analysing the impact
of the resulting fluid and solid motion on solute transport. We first
characterise the independent roles of the three main mechanisms of solute
transport in porous media - advection, molecular diffusion, and hydrodynamic
dispersion - by examining their impacts on the solute concentration profile
during one loading cycle. We next explore the impact of the transport
parameters, showing how these alter the relative importance of diffusion and
dispersion. We then explore the loading parameters by considering a range of
loading periods - from slow to fast, relative to the poroelastic timescale -
and amplitudes - from infinitesimal to large. We show that solute spreading
over several loading cycle increases monotonically with amplitude, but is
maximised for intermediate periods because of the increasing poromechanical
localisation of the flow and deformation near the permeable boundary as the
period decreases.
