Transport of Kinetically Adsorbing Contaminants in Randomly Heterogeneous Aquifers

One of the most promising approaches for modeling solute transport in heterogeneous aquifers describes the natural variability in hydraulic conductivity by means of a stationary random field. Therefore, the solute concentration distribution at a given time also becomes a random field. For the case of an inert solute, Dagan found a solution for the temporal evolution of the ensemble spatial moments of the concentration random field; this solution describes the impact of small-scale heterogeneity upon large-scale spreading of the plume (the so-called macrodispersion phenomenon). We extend Dagan's results to the case of a reactive solute undergoing linear reversible adsorption. We assume spatially uniform kinetic rate coefficients. The solution obtained explicitly quantifies the combined effect of nonequilibrium adsorption reactions and macrodispersion, for a range of possible time scales of both processes. We show that for very large times the effects of macrodispersion and kinetics are additive, while for shorter times they are related in a nonlinear fashion. As a particular application of the theory, we demonstrate that the conditions necessary for the existence of local equilibrium depend not only on the kinetic rate coefficients but also upon the spatial structure of the conductivity field.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Civil Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Quinodoz, Hernan Alfonso Maria

Contributors dc:contributor

• Valocchi, Albert J.

• Hydrology
• Engineering, Civil
• Engineering, Sanitary and Municipal
• Environmental Sciences

Identifier

(UMI)AAI9305660

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/72195