Local equilibrium and retardation revisited
S.K. Hansen, V.V. Vesselinov
Groundwater2017DOI 10.1111/gwat.12551
Summary
In modeling solute transport with mobile-immobile mass transfer (MIMT), it is common to use an advection-dispersion equation (ADE) with a retardation factor, orretarded ADE. This is commonly referred to as making thelocal equilibrium assumption(LEA). Assuming local equilibrium, Eulerian textbook treatments derive the retarded ADE, ostensibly exactly.