es030029d_si_001.pdf (174.61 kB)
Modeling Expected Solute Concentration in Randomly Heterogeneous Flow Systems with Multicomponent Reactions
journal contribution
posted on 2004-05-01, 00:00 authored by Maria E. Malmström, Georgia Destouni, Philippe MartinetMany environmental problems require assessment of
extensive reaction systems within natural subsurface flow
systems exhibiting large physical and biogeochemical
heterogeneity. We present an approach to couple stochastic
advective-reactive modeling of physical solute transport
(LaSAR) with the geochemical model PHREEQC for modeling
solute concentrations in systems with variable flow
velocity and multicomponent reactions. PHREEQC allows
for general and flexible quantification of a multitude of linear
and nonlinear geochemical processes, while LaSAR
efficiently handles field-scale solute spreading in stochastic
heterogeneous flow fields. The combined LaSAR−PHREEQC approach requires very modest computational
efforts, thereby allowing a large number of reactive transport
problems to be readily assessed and facilitating handling
of quantifiable uncertainty in environmental model
applications. Computational efficiency and explicit handling
of field-scale dispersion without introduction of excessive
fluid mixing that may impair model results are general
advantages of the LaSAR compared with alternative solute
transport modeling approaches. The LaSAR−PHREEQC
approach is restricted to steady or unidirectional flow fields,
and our specific application examples are limited to
homogeneous reaction systems without local or transverse
dispersion-diffusion, although these are not general
methodological limitations. As a comprehensive application
example, we simulate the spreading of acid mine drainage
in a groundwater focusing on Zn2+ and including relevant,
major-component geochemistry. Model results show that
Zn2+ may be substantially attenuated by both sorption and
precipitation, with flow heterogeneity greatly affecting
expected solute concentrations downstream of the mine
waste deposit in both cases.
History
Usage metrics
Categories
Keywords
geochemical model PHREEQCapplicationnonlinear geochemical processesalternative solute transport modeling approachesheterogeneityflow fieldsreaction systemsmodeling solute concentrationsModel results showmine waste depositZnacid mine drainagereactive transport problemshandlingRandomly Heterogeneous Flow SystemsLaSAR
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC