Model
Formulation; Assessment of Model Components and Parametrization.
The mobility and transport of trace metals in groundwater systems is
strongly affected by biological activities. Biological processes can
be exploited to immobilize trace metals or alternatively mobilize them
to accelerate cleanup of contaminated sites. Ongoing efforts of researchers
of the NABIR program are focusing on the many biological and geochemical
processes that impact trace metal mobility in groundwater systems. The
proposed research aims to lay the foundations for constructing reliable
models. An assessment will be made on the laboratory and field data
needed to generate a hierarchy of models of varying fidelity. The study
will involve surveying the current NABIR experimental efforts and contacting
the PI's as well as drawing together a prioritized host of modeling
tools and issues. The outcome of this one-year study will be a document
presenting a set of plans, needs, and recommendations for generating
a set of models with the aim for coordinating with NABIR experiments
to assess the fate of trace metal contaminants in groundwaters during
bioremediation processes.
Assessment
of Model/Data Links. Regardless of the outcome of the planning effort
described in Section I and the level of complexity of the final models,
two initiatives will be required for any formulation interfaced with
the data being collected: (1) identification of suitable means to couple
biological reactive transport with chemical speciation, (2) implementation
of nonlinear mathematical techniques to identify the key variables and
their correlations, so that the structure observed in the field is preserved
in the models. As these efforts are generic to any future model development,
we suggest that they be given immediate priority to assure an efficient
and sound initiation of the subsequent model development program.
The field
study that is being conducted at the South Oyster field research site
as part of the NABIR project provides an ideal setting for such an effort.
This effort will exploit the data obtained at this site for the purposes
discussed above.