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……