Estimation–identification problem for diffusive transport in porous materials based on single reservoir test: Results for silica hydrogel

In this paper the problems of selection of an appropriate model of diffusive transport in silica hydrogel and estimation of model parameters are considered. The analytical solutions and simulations of diffusive transport in a single reservoir test with equilibrium model of sorption are developed. The mathematical models refer to transport of solute from a porous material to water or in reverse direction assuming arbitrary initial concentrations and Dirichlet or mixed type of boundary conditions. In order to quantify the relative importance of the model parameters, logarithmic sensitivity analysis of solute concentration with respect to estimated parameters describing diffusion, sorption, and interfacial effects is performed. The application of the discussed models for estimation of transport parameters is discussed using experimental results for diffusion of sodium chloride in silica hydrogel.

Analytical solutions, simulations, and sensitivity analysis of model of diffusive transport in porous material studied in the single reservoir test are presented. Equilibrium sorption, arbitrary spatially homogeneous initial concentrations, and Dirichlet or mixed type of boundary conditions are assumed. The identification procedure to find the model and parameters of diffusive transport is presented for silica hydrogel.Figure optionsDownload as PowerPoint slide