HR: 1340h
AN: B33C-1043 [Abstracts]
TI: New tools and concepts for understanding the evolution of mineral surface area for extrapolation of
environmental kinetics
AU: * Mueller, K
EM: ktm2@psu.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AU: Bandstra, J
EM: bandstra@ebs.ogi.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AU: Kubicki, J
EM: kubicki@geosc.psu.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AU: Criscenti, L
EM: ljcrisc@sandia.gov
AF: Sandia, National Laboratory, Albuquerque, NM 87185
United States
AU: Moore, J
EM: jxm957@psu.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AU: Washton, N
EM: nam@babylon.chem.psu.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AU: Brantley, S
EM: sxb7@psu.edu
AF: Center for Environmental Kinetics Analysis, 2217 EES Building, Univ Pk, PA 16802
United States
AB:
To extrapolate geochemical kinetics of abiotic mineral-water reactions across scales, one must quantify the rate constants
for reaction, activities of solution species involved in the reaction, and the surface area or reactivity of the
mineral-water interface. While significant effort has focused on modeling rate constants as a function of mineral and
solution composition, the complexities involved in measuring and predicting the mineral-water interfacial area and reactivity
have not been systematically addressed. In general, the surface area and reactivity are coupled to dissolution since we
know that roughness and reactivity vary as the dissolving surface evolves. In some cases, however, roughness, reactivity,
and surface site density may reach steady state values. We have begun an investigation to compare the reaction kinetics of
clusters of molecules modeled with ab initio techniques to the stochastic evolution of model mineral surfaces and to NMR
measurements related to reactive surface area. Such a comparison will yield conceptual tools to predict temporal evolution of
the surface area and reactivity terms, and should further our capacity to predict environmental kinetics.
DE: 0463 Microbe/mineral interactions
SC: Biogeosciences [B]
MN: Fall Meeting 2005