Premium
Mass arrival of sorptive solute in heterogeneous porous media
Author(s) -
Cvetkovic Vladimir D.,
Shapiro Allen M.
Publication year - 1990
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr026i009p02057
Subject(s) - sorption , hydraulic conductivity , desorption , thermodynamics , non equilibrium thermodynamics , porous medium , chemistry , materials science , soil science , porosity , physics , adsorption , environmental science , soil water , organic chemistry
The stochastic arrival time analysis of nonreactive solute movement in heterogeneous porous media is extended to consider solute that undergo sorption‐desorption governed by first‐order linear kinetics. For an instantaneous solute injection, a general expression for the expected mass flux at any distance from the injection point is derived in terms of the three‐dimensional velocity field and the forward‐ and reverse‐sorption rate coefficients. This general expression is reduced for three special cases: (1) equilibrium sorption‐desorption where the retardation coefficient is either correlated or uncorrelated with the hydraulic conductivity field, (2) solute degradation where the rate coefficient is uncorrelated with the hydraulic conductivity, and (3) nonequilibrium sorption‐desorption with constant sorption rate coefficients. These cases are analyzed for a lognormally distributed and statistically isotropic spatial correlation of the hydraulic conductivity; other assumptions of spatial correlation in the hydraulic conductivity can also be used. The influence of spatial variability in the sorption rate coefficients for nonequilibrium sorption‐desorption is investigated for the special case of a stratified porous medium. For equilibrium sorption‐desorption, the spatial variability in the retardation coefficient may notably delay the breakthrough of solute at a given location. The spatial variability in the degradation parameter does not influence solute breakthrough significantly for the considered range of parameters. For a stratified porous medium, spatial variability in the sorption rate coefficients has a significant effect on the cumulative mass arrival at a given location. Using the harmonic mean of the sorption rate coefficients most closely approximates the results generated using variable sorption‐rate coefficients for the stratified formation case.