Applied Research Center Florida International University

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Applied Research CenterFlorida International
University
Remediation and Treatment Technology Development
and Support Modeling Mercury Distribution in the
Watersheds of the Oak Ridge Reservation MIKE
SHE and MIKE 11
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Water Environmental Resources Group
Rajiv Srivastava, PhD Associate
DirectorGeorgio Tachiev, PhD Project
ManagerAngelique Lawrence, MS, GISP Research
AnalystPrabhakar Pant, MS, PWS Research
ScientistWeihua Zhang, PhD Research
ScientistYelena Katsenovich, PhD Research
Scientist
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Background

• FIU-ARC is providing technical assistance and
  performing research on mercury remediation at the
  Oak Ridge site through
• TASK I Modeling of mercury speciation and
  distribution under buildings at Oak Ridge in the
  soil and groundwater.
• Provide new insight to the potential risks of
  mercury contamination during D D operations and
  thus develop strategies to minimize it.
• TASK II Identification and characterization of
  point and non-point sources of mercury in the
  LEFPC watershed to derive a conceptual model for
  the site with regard to mercury mass balance.
• Re-establishing framework for Hg TMDL criteria
  currently established by EPA.

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MIKE SHE MIKE 11

• MIKE SHE - Numerical Integrated Hydrology
  Modeling
• Covers the entire land phase of the hydrological
  cycle
• Not just a 3-D numerical groundwater model -
  Includes numerical models for
• overland flow
• unsaturated flow
• solute transport
• agricultural practice
• evapotranspiration
• By default coupled to MIKE 11
• Ideal for distributed rainfall-runoff modeling
• MIKE 11 - River and Channel Hydraulics
• Versatile one-dimensional hydrodynamic software
  package
• Includes process modules for
• advection-dispersion
• water quality and ecology
• sediment transport
• rainfall-runoff
• flood forecasting

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MIKE SHE Integrated
Surface Water and Ground Water Model

• Dynamic, user-friendly modeling tool
• Can simulate entire land phase of hydrologic
  cycle
• Is applicable on spatial scales ranging from
  single soil profiles (for infiltration studies)
  to regional watershed studies
• Integrated modeling environment
• Links regional and local scale models
• Can be linked to ESRI's ArcView for advanced GIS
  applications
• Includes advanced tools for
• Manipulating time varying data
• Model calibration
• Water and mass balance analysis
• Proven track record in hundreds of consultancy
  and research applications worldwide

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MIKE SHEHydrologic Processes simulated by MIKE
SHE
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MIKE 11Dynamic modeling of river, channel and
reservoir hydraulics
Industry standard for simulating Flow and water
level Water quality and sediment transport in
rivers, flood plains, irrigation canals,
reservoirs and other inland water
bodies Transport and spreading of conservative
pollutants and constituents with linear decay
(including heat). Dynamic integration with other
DHI software allows integration of river
floodplain models with models for watershed
processes, detailed floodplain representation,
sewer systems coastal processes Links to
external groundwater models and is OpenMI
compliant Significant components for FIU-ARC
work GIS Extension - Powerful extension for
ArcMAP providing features for Catchment/river
delineation Cross-section and DEM data Pollution
load estimates Flood visualization/animation as
2D maps Results presentation/analysis using
Temporal Analyst Stream Flow Characteristics and
Solute Transport modules. Includes Unit
hydrograph method A lumped conceptual continuous
hydrological model A monthly soil moisture
accounting model
Reference Graham, D.N. and M. B. Butts (2005)
Flexible, integrated watershed modelling with
MIKE SHE. Watershed Models, Eds. V.P. Singh
D.K. Frevert Pages 245-272, CRC Press. ISBN
0849336090.
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MIKE 11Modeling of non-point pollution
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Thank youQuestions?
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Thank youQuestions??
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• An integrated model showing the groundwater table
  as function of time for a period of 10 years. The
  following specifications are included
• -evapotranspiration
• -precipitation
• -saturated groundwater flow
• -unsaturated groundwater flow
• -river flow
• -exchange between
• River and groundwater
• Saturated and usaturated zone

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COMSOL MultiphysicsEarth Science Module

• Simulates physics involved in fluid flow, heat
  transfer, and solute transport
• Includes modeling interfaces for
• Heat Transfer
• Richards equation
• Darcys Law
• Solute transport in saturated and variably
  saturated media
• Also offers
• Unlimited multiphysics couplings - Ties
  seamlessly into COMSOL Multiphysics and other
  auxiliary modules to truly model coupled
  phenomena in the earth. These include
  poroelasticity, electromagnetic fields, acoustic
  and structural behavior, and chemical reactions.
• Equation-based modeling - All material
  properties, source terms, and boundary settings
  can be represented by any arbitrary function of
  pressure, temperature, concentrations, stress, or
  any other variable or parameter In particular,
  full two-phase flow in porous media can be
  simulated in this way.
• Accessing data - The module features unsurpassed
  ease with which users can work with
  field-gathered data and then couple these to
  descriptions of material properties.

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COMSOL Multiphysics 2-Phase Flow in Porous Media

• Flow of air and water within the domain. Uses
  Richards equation to describe
• Flow in Saturated zone
• Flow in Unsaturated zone
• Gas flow
• Transport of mercury in variably saturated media
  and in the gas phase. Takes into account exchange
  with infinite layer above the domain by diffusion
  and convection (wind effects)
• Incorporates physicochemical behavior of Hg in
  soil, water, air phases
• Adsorption
• Bio- and chemical transformation

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Visual MINTEQ

• This model is used for calculating the
  equilibrium mass distribution among dissolved
  species, adsorbed species, and multiple solid
  phases under a variety of conditions including a
  gas phase with constant partial pressures.
• Used to calculate equilibrium composition of
  aqueous solutions in ORR groundwater contaminated
  with 0.2µg/L of mercury.
• Field and laboratory analytical data used in the
  model were acquired from the OREIS database.

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Visual MINTEQ

• Mercury binding to humic substances is an
  important process in ground and surface waters.
• Visual MINTEQ permits use of three (3) different
  models for computing the complexation of mercury
  by dissolved organic matter (DOM).
• Gaussian
• Does not seem to compute mercury bound to DOM and
  results with DOM input were not differing from
  the inorganic mercury compounds distribution
  without DOM.
• NICA-Donnan Model Stockholm Humic Model (SHM)
• Results from these suggest that mercury is in the
  dissolved phase and almost 99.89 bound to DOM
  with concentrations starting as low as 0.5ppm.
• NICA-Donnan model is available only for aqueous
  mercury speciation and provides comparison
  between site-specific fulvic acid (FA), which are
  type 1 (carboxylic - FA1) and type 2 (phenolic
  and other - FA2).
• Preliminary modeling results indicate that the
  percentage of mercury bound to FA1 and FA2
  depends on groundwater ORP conditions.

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GEMS-PSI   Gibbs Energy Minimization
Selektor(PSI version)for Geochemical
Equilibrium Modeling

• Broad-purpose geochemical modeling code using an
  advanced convex programming method of Gibbs
  Energy Minimization (GEM) implemented in an
  efficient Interior Points Method (IPM) numerical
  module.
• Can compute equilibrium phase assemblage and
  speciation in a complex chemical system from its
  total bulk elemental composition at given
  temperature and pressure (optionally, with some
  metastability or kinetic constraints).
• Chemical interactions involving (dispersed)
  solids, solid solutions, gas mixture, aqueous
  electrolyte  (non-)electrostatic surface
  complexation, and ion exchange can be considered
  simultaneously in the chemical elemental
  stoichiometry ( electrical charge) of the
  system, i.e. without any additional mass balance
  constraints for ligands or surface sites.

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Progress To Date

• Delineation of Lower East Fork Poplar Creek
  (LEFPC) and White Oak Creek watersheds/sub-catchme
  nts using ArcGIS and the ArcHydro model.

• Preliminary simulation of overland and saturated
  flow in the White Oak Creek Watershed using MIKE
  SHE

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Progress To Date

• Creation of 3-D mesh for topography of Central
  Bethel Valley area to examine mercury
  contamination within ORNL area at a smaller scale
  as opposed to a watershed perspective.
• Creation of 3-D visualizations for Central Bethel
  Valley mercury contamination.

Melton Valley Access Rd
Bldgs. 4501/4505
Bethel Valley Rd.
White Oak Creek
2005 GW Hg. Conc. (µg/L)
First Creek
7500 Bridge
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Path Forward

• A multidisciplinary approach to complex
  environmental problems
• Physico-Chemistry, experimental work
• Transport on microscale
• GIS and regional modeling
• Regulatory compliance

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Project Overview

• Saltcake dissolution studies
• Hydraulic properties of saltcake simulants
• Oxidative Leaching
• Gas Release and Retention
• Modeling of flow through saltcake

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Saltcake Dissolution
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Saltcake Dissolution
Experimental Scale
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Saltcake Dissolution
Preferential Flow and DIssolution
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Saltcake Dissolution
Beginning and end of dissolution
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Saltcake Dissolution
Retrieval Efficiency
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Saltcake Dissolution
Sodium Retrieval Patterns
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Saltcake Dissolution
Aluminum Retrieval Patterns
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Saltcake Dissolution
Nitrite Retrieval Patterns
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Saltcake Dissolution
Phosphate Retrieval Patterns
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Hydraulic Parameters
Inverse modeling of effluent rates using van
Genuchtens theory for variably saturated flow
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Hydraulic Parameters
Hydraulic properties of aging simulant
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Hydraulic Parameters
Variation of hydraulic conductivity
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Hydraulic Parameters
Tracer Studies
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Numerical Modeling
Continuous retrieval and dispersion factors
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Numerical Modeling
Incremental Drainage and Resaturation
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Oxidative Leaching
Chromium (III) speciation
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Oxidative Leaching
Chromium (III) speciation
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Oxidative Leaching
Pu Predominance Diagram
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Oxidative Leaching
Pu Predominance Diagram
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Gas Release and Retention
Experimental Setup
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Gas Release and Retention
Argon Injection and Release
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Gas Release and Retention
Argon Injection and Release Time constants
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THE END
End