HR: 13:40h
AN: H13I-01    [Abstracts]
TI: Experimental and Theoretical Investigations of Reaction-Coupled Flow and Transport in Porous Media
AU: * Kim, J
EM: jkkim@kowaco.or.kr
AF: Korean Institute of Water and Environment, Korean Water Resources Corporation San 6-2 Yeonchuk dong Daedeok-gu, Daejeon, 306-711 Korea, Republic of
AU: Schwartz, F W
EM: schwartz.11@osu.edu
AF: Department of Geological Sciences, The Ohio State University 125 S. Oval Mall, Columbus, OH 43210 United States
AB: In some systems, it is possible to observe complex patterns of coupling between fluid and flow and mass transport when reactions involving a solid phase are operative. For example, dissolution and precipitation reactions can change a porous medium's physical properties such as porosity and permeability. These changes influence fluid flow, which affect the concentration of dissolved solids, the composition of solid phases, and the rate and direction of advective transport. Both experimental and modeling studies were conducted to investigate the coupling between flow and transport due to effects of fluid density, dissolution/precipitation reactions, and heterogeneity in medium properties. The complex chemical system is created by pumping a dilute Fe(ClO4)3 solution through a medium created by mixing glass beads and crushed calcite. Fe3+ rapidly hydrolyzes to produce hydroxo complexes and H+. As pH increases through reaction with calcite, a poorly crystallized solid, ferric oxyhydroxide precipitates. Two-dimensional flow tank studies are use to verify a novel modeling approach. In the model, there is full coupling of flow and transport due to permeability changes from dissolution/precipitation reactions. Further, TOUGHREACT is used to study reaction-front dynamics, and how the aqueous phase concentrations depend upon this pattern of evolution. Both the experimental and theoretical results highlight the complexity of coupling in systems with heterogeneous reactions. The important implication of this study is that details of interactions between pore fluid and the porous medium need to be well characterized in order to predict the changing aqueous concentrations.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting