A Geologic Framework for ReactiveA Geologic Framework for Reactive
Solute Transport Properties inSolute Transport Properties in
Sedimentary AquifersSedimentary AquifersDOE-ERSP Annual PI Meeting, April 7, DOE-ERSP Annual PI Meeting, April 7, ‘‘0808
Richelle M Allen-KingRichelle M Allen-King
University at Buffalo (SUNY)University at Buffalo (SUNY)
Heterogeneous distributions ofHeterogeneous distributions of
reactive transport propertiesreactive transport properties
Permeability, kPermeability, k
Reactivity, Reactivity, KdKd, , krkr, etc., etc.
k & k & KdKd ??
k & k & KdKd ??
k & k & KdKd ??
k & k & KdKd ??
SurficialSurficial geology of the US is... geology of the US is...
Surficial geology of US (Sollar & Reheis,
compilers, USGS open file report, 03-275
mostly sedimentary
sediments are blues,sediments are blues,greens, oranges, yellowsgreens, oranges, yellows
residual materialsresidual materialsdeveloped on sedimentarydeveloped on sedimentaryrocks are purples)rocks are purples)
in direct contact with anthropogenicpollutant sources
a
b
c
vv(a,b,or(a,b,or c)c)= = ff(K(Kii,Kd,Kdii,k,kii))
G d t flGround water flow
a
c
a
b
c
vv(a,b,or(a,b,or c)c)= = ff(K(Kii,Kd,Kdii,k,kii))
G d t flGround water flow
a
c
ConceptualConceptual
Model ofModel of
AquiferAquifer
HeterogeneityHeterogeneity
Erosion,Erosion,
transport,transport,
depositiondeposition
a
b
c
Facies 1
2
3
SourceSource
materialsmaterials
vv(a,b,or(a,b,or c) c)= = ff(K(Kii,Kd,Kdii))
Ground water flowGround water flow
Borden plumesBorden plumesGeologically youngGeologically young
sedimentssediments
Plumes (CT&PCE)Plumes (CT&PCE)
~20-400 m~20-400 m33 w/ w/
transport distancestransport distances
of meters to tens ofof meters to tens of
mm’’ss
Organic Organic CarbonaceousCarbonaceous
ContaminantContaminant MatterMatter
+
‘‘SimpleSimple’’
(sorption/(sorption/desorptiondesorption))
reactionreaction
Heterogeneous BordenHeterogeneous Borden
carbonaceous mattercarbonaceous matter
Petrography by Bertrand Petrography by Bertrand LouigiLouigi, University of , University of TTüübingenbingen
Incident white lightIncident white light Fluorescence modeFluorescence mode
••FusiniteFusinite
••VitriniteVitrinite ( (aVaV) w/) w/
small small inertiniteinertinite (i) (i)
••VitriniteVitrinite in amorphous groundmass in amorphous groundmass
••AmorphousAmorphous
organicorganic
matter inmatter in
networknetwork
~64 ~64 μμmm
~164 ~164 μμmm
~100 ~100 μμmm
~72 ~72 μμmm
AdAdsorption dominates atsorption dominates at
low aqueous concentrationlow aqueous concentration
Absorption (the standard empirical approach)Absorption (the standard empirical approach)dominates at high relative concentrations,dominates at high relative concentrations,C>~0.5%solubilityC>~0.5%solubility
10
1000
100000
10 1000 100000
C [ug/L]
q [
ug
/k
g]
observed
absorption
adsorption
total
0
10,000
20,000
30,000
0 10 20 30 40 50 60
Displacement (m)
C (
ug
/L)
NonreactiveLinear
Nonlinear
Impact of grain-scaleImpact of grain-scale
heterogeneity on transportheterogeneity on transport
ClCl and PCE and PCE
solutionsolution
Measure Measure
[[ClCl] and [PCE]] and [PCE]0.0
0.1
0.2
0.3
0 10 20 30 40 50
Displacement (m)
C/C
o Nonreactive
Linear
High C,
Nonlinear
0.0
0.1
0.2
0.3
0 10 20 30 40 50
Displacement (m)
C/C
o Nonreactive
Linear
High C,
NonlinearLow C,
Nonlinear
a
b
c
vv(a,b,or(a,b,or c)c)= = ff(K(Kii,Kd,Kdii,k,kii))
G d t flGround water flow
a
c
a
b
c
vv(a,b,or(a,b,or c)c)= = ff(K(Kii,Kd,Kdii,k,kii))
G d t flGround water flow
a
c
ConceptualConceptual
Model ofModel of
AquiferAquifer
HeterogeneityHeterogeneity
Erosion,Erosion,
transport,transport,
depositiondeposition
a
b
c
Facies 1
2
3
SourceSource
materialsmaterials
vv(a,b,or(a,b,or c) c)= = ff(K(Kii,Kd,Kdii))
Ground water flowGround water flow
Contour plot of Contour plot of lnln-transformed-transformed
permeability from 11 corespermeability from 11 cores
N=859
5 6 7 8 9 10 11 12 13 14 15
horizontal distance along section (m)
-3.0-2.5-2.0
depth
bgs
(m)
-17.00 -15.89 -14.78 -13.67
MCGMCG
massivemassive
coarse grainedcoarse grained
DPLDPL
distinct planedistinct plane
laminatedlaminated
MFG MFG
massive massive
fine grainedfine grained
Create Create ‘‘indicatorindicator’’ data data
by mapping by mapping lithofacieslithofacies
IndicatorIndicator
cross sectioncross section
MCGMCG
DPLDPL
MFG MFG
Permeability (k) distributionPermeability (k) distribution
differs by differs by lithofacieslithofacies
0
0.2
0.4
0.6
0.8
1
-17 -16 -15 -14 -13
ln k
cu
mu
lati
ve d
istr
ibu
tio
n
fun
cti
on Z
DPL
MFG
MCG
Z=silt
DPL=distinct plane
laminated
MFG=massive fine
grained
MCG=massive
coarse grained
MCGMCG
DPLDPL
MFG MFG
Permeability contrasts focus flowPermeability contrasts focus flow
Geophysical data provides Geophysical data provides faciesfacies
classifications between coresclassifications between cores
Permeability-reactivity relation isPermeability-reactivity relation is
not simple!not simple!
-3
-2
-1
0
1
2
-17 -16 -15 -14 -13ln k [ln (cm2)]
ln P
CE
Kd
[ln
(m
L/g
)]
FaciesFacies (or groups of (or groups of faciesfacies) have) have
distinct permeability & reactivity distinct permeability & reactivity cdfscdfs!!
0
0.2
0.4
0.6
0.8
1
-17 -16 -15 -14 -13
ln k
cu
mu
lati
ve d
istr
ibu
tio
n
fun
cti
on Z
DPL
MFG
MCG
0
0.2
0.4
0.6
0.8
1
-3 -2 -1 0 1 2
ln Kd
cu
mu
lati
ve
dis
trib
uti
on
fun
cti
on
Z
DPLMFG MCG
Different distribution patterns indicate that neither (+) or (-)
k-Kd correlation is appropriate (as commonly assumed)
Representative lithofacies samples from >90 cores and
based on nKd>500; nk>1100
Reactivity and permeability areReactivity and permeability are
correlated to correlated to lithofacieslithofacies
LithofaciesLithofacies
Permeability, kPermeability, k Reactivity, Reactivity, KdKd
0
0
permeability
rea
cti
vit
y
Correlation is not simpleCorrelation is not simple
MCGMCG
DPLDPL
MFG MFG
Hanford plumeHanford plumeGeologically oldGeologically old
sediments withsediments with
significantsignificant
diagenesisdiagenesis
CT PlumeCT Plume
~ 0.5 km~ 0.5 km33 & &
transporttransport
distances ofdistances of
kmskms
More complex reactions More complex reactions ––
redoxredox and pH sensitive and pH sensitive
e- Cl-
S-Fe(II)S-Fe(III)
+
ConclusionsConclusions
Plume transport dynamics can be controlled byPlume transport dynamics can be controlled by
geochemistrygeochemistry
Extremely small proportion of the total aquiferExtremely small proportion of the total aquifer
comprising very small particles can controlcomprising very small particles can control
on transport.on transport.
Spatial information and underlying geochemicalSpatial information and underlying geochemical
(and physical) sedimentary aquifer(and physical) sedimentary aquifer
properties can be obtained throughproperties can be obtained through
lithofacieslithofacies mapping and correlation mapping and correlation
Questions - aquifer propertyQuestions - aquifer property
heterogeneity & reactive transportheterogeneity & reactive transport
What are the What are the biogeochemicallybiogeochemically reactive reactive
sites?sites?
What is the relationship of the reactivityWhat is the relationship of the reactivity
and permeability?and permeability?
At what spatial scales must we defineAt what spatial scales must we define
the aquifer reactivity and permeability inthe aquifer reactivity and permeability in
order to predict reactive transport?order to predict reactive transport?
AcknowledgementsAcknowledgements
CollaboratorsCollaborators
Rabideau, UBRabideau, UB
Knight & Moysey,Knight & Moysey,
StanfordStanford
Ritzi & Domenic, WrightRitzi & Domenic, Wright
State UState U
Weissmann, UNMWeissmann, UNM
Murray & Scheibe,Murray & Scheibe,
PNNLPNNL
Students and Students and PostdocsPostdocs
Polmanteer, Lilienthal,Polmanteer, Lilienthal,
Wang, Wang, McGraneMcGrane
Divine, Taylor & manyDivine, Taylor & many
undergrad researchersundergrad researchers
Financial sponsorsFinancial sponsors
NSF, HydrologicNSF, Hydrologic
SciencesSciences
DOE-This program!DOE-This program!
UB UB HydrogeochemHydrogeochem EnviroEnviro geosciences faculty geosciences faculty
Is micro-scale chemical heterogeneityIs micro-scale chemical heterogeneity
important to R prediction?important to R prediction?
What is the What is the sorbentsorbent causing causing
contaminant retardation?contaminant retardation?
Where is the Where is the sorbentsorbent??
What are the characteristics of What are the characteristics of sorbentsorbent
interactions with PCE?interactions with PCE?
Groundwater contaminantGroundwater contaminant
transporttransport
Predictions (models) used to:Predictions (models) used to:
•• To estimate long term societal/ecologicalTo estimate long term societal/ecological
impactsimpacts
•• Assign risk to prioritize remediation needsAssign risk to prioritize remediation needs
•• Plan efficient remedial designPlan efficient remedial design
Understanding and incorporatingUnderstanding and incorporating
heterogeneous distributions of subsurfaceheterogeneous distributions of subsurface
properties properties authenticallyauthentically will allow us to do will allow us to do
all of these better!all of these better!
Impact of grain-scaleImpact of grain-scale
heterogeneity on transportheterogeneity on transport
CFB BordenCFB Borden
Comparison betweenComparison between
distributions distributions –– same variance! same variance!
5 6 7 8 9 10 11 12 13 14 15
horizontal distance along section (m)
-3.0-2.5-2.0
dept
h bgs
(m
)
-2.50 -1.39 -0.28 0.83 1.94
5 6 7 8 9 10 11 12 13 14 15
horizontal distance along section (m)
-3.0-2.5-2.0
depth
bgs
(m)
Ln Kd
Ln k
Spatial distribution of Spatial distribution of lnln ( (KdKd))
N=374
5 6 7 8 9 10 11 12 13 14 15
horizontal distance along section (m)
-3.0-2.5-2.0
dept
h bgs
(m
)
-2.50 -1.39 -0.28 0.83 1.94
ES plume demonstrates ES plume demonstrates ““idealideal””
retardationretardation
0
2
4
6
0 200 400 600 800
Time (day)
R
ES Test
SW Test*
*Roberts et al., 1986
PCE
water
v
vR =
Empirical(Kd=Kocfoc)
Competitive sorption canCompetitive sorption can
result in transport trendsresult in transport trends
~3.8-6.3~3.8-6.32.7-5.92.7-5.9SWSW
1.7-2.61.7-2.61.4-2.01.4-2.0ESES
PredictedPredictedObservedObserved
10
1000
100000
10 1000 100000
C [ug/L]
q [
ug
/kg
]
Summary from our plumeSummary from our plume
sagasaga……
Different R (and trending R in SW) behavior isDifferent R (and trending R in SW) behavior is
consistent with our hypotheses about:consistent with our hypotheses about:
•• the grain-scale geochemical properties of thethe grain-scale geochemical properties of the
sorbentsorbent & &
•• interactions with contaminantsinteractions with contaminants
Enhanced dispersion in SW test is consistentEnhanced dispersion in SW test is consistent
with the plume-scale distribution of sedimentwith the plume-scale distribution of sediment
geochemical propertiesgeochemical properties
LithofaciesLithofacies predict k well in predict k well in
most casesmost cases
0
0.2
0.4
0.6
0.8
1
-18 -17 -16 -15 -14 -13
lnk
cd
f
Z
XSS
LPXS
Comparisons between twoComparisons between two
mapped directionsmapped directions
Permeability well predicted for 7 of 9Permeability well predicted for 7 of 9
lithofacieslithofacies
Poor predictions for two Poor predictions for two faciesfacies
•• (sorting implicated, ongoing work)(sorting implicated, ongoing work)
LithofaciesLithofacies distribution is also well distribution is also well
predictedpredicted
•• fraction of occurrencesfraction of occurrences
•• average thicknessaverage thickness
Borden & Hanford Borden & Hanford ‘‘bookendsbookends’’
~0.5 km~0.5 km33
10s of 10s of kmskms
~20 ~20 –– 400 m 400 m33
10s of meters10s of meters
Plume size &Plume size &
transport distancestransport distances
Old (Pliocene),Old (Pliocene),
significantsignificant
diagenesisdiagenesis
Young,Young,
little little diagenesisdiagenesis
SedimentsSediments
????Retarded,Retarded,
not transformednot transformed
CTCT
HanfordHanfordBordenBorden
Highlight some insightsHighlight some insights
And some outstanding questionsAnd some outstanding questions
Questions Questions –– at what at what scale(sscale(s) and for what problems do rate limited) and for what problems do rate limitedreactions at the grain scale limit overall mass flux (source/sink)reactions at the grain scale limit overall mass flux (source/sink)
Flux concept (not just concentration)Flux concept (not just concentration)
What features (physical, What features (physical, lithologiclithologic) and at what resolution (particularly) and at what resolution (particularlyin the vertical) do (various) geophysical techniques resolve in the vertical) do (various) geophysical techniques resolve lithologylithology,,what what hydrogeologichydrogeologic property insights are gained from geophysical work property insights are gained from geophysical work
Stochastic versus deterministic (type) approaches and scale ofStochastic versus deterministic (type) approaches and scale oftransporttransport
What scale of geochemical and physical What scale of geochemical and physical heterogeneityiesheterogeneityies combined combinedaffect (control) reactive solute transport (or have significant affects on)affect (control) reactive solute transport (or have significant affects on)
very fine particles and/or a very tiny proportion of the aquifer material very fine particles and/or a very tiny proportion of the aquifer materialcan exert an impact on overall plume transportcan exert an impact on overall plume transport
What is the relationship between k and What is the relationship between k and KdKd
notesnotes
Add flow arrows to cross sectionAdd flow arrows to cross section
Wrap up word slide provides summary of importance of Wrap up word slide provides summary of importance of sedsedarchitecture on architecture on hydrogeologichydrogeologic picture picture
What about geophysics What about geophysics –– well, what do the GPR images well, what do the GPR imagesactually show us? What information at what spatial scales doesactually show us? What information at what spatial scales doesgeophysics provide? (a vignette here)geophysics provide? (a vignette here)
Important for small scale field efforts that, in many ways mimicImportant for small scale field efforts that, in many ways mimicscale of importance for contaminant transportscale of importance for contaminant transport
Aside notes Aside notes –– important themes on what scale of geologic important themes on what scale of geologicfeatures (heterogeneity) impact transport features (heterogeneity) impact transport acrrossacrross an entire an entireplume? (maybe quite small), what plume? (maybe quite small), what proporstionsproporstions and so and so ontont……