Phytoremediation of Phytoremediation of VOC’sVOC’s: Understanding : Understanding

Fate & Innovative ApplicationsFate & Innovative Applications

Joel G. BurkenJoel G. BurkenCivil, Architectural & Environmental EngineeringCivil, Architectural & Environmental Engineering

Univ. of MissouriUniv. of Missouri--Rolla Rolla

AcknowledgementsAcknowledgementsUMR: UMR: Graduate students Xingmao Ma, Garrett Graduate students Xingmao Ma, Garrett

Struckhoff, Jeff Weishaar, Sally BreiteStruckhoff, Jeff Weishaar, Sally Breite

USGS:USGS: John SchumacherJohn Schumacher

Weston Solutions: Weston Solutions: Matt McCaughey, Bill SchneiderMatt McCaughey, Bill Schneider

Univ. South CarolinaUniv. South Carolina:: Lee NewmanLee Newman

USGS

Volatile Compounds

Organics, metals

Xylem

Enhanced Biodegradation

Phloem

Phytoremediation ProcessesContaminant interactions•VOC Uptake & Volatilize•Plant Degradation•Enhanced Biodegradation

Volatile Compounds

Plant metabolism

Tree CoringTree CoringMethods: D. VrobleskyMethods: D. VrobleskyCollect a core sample of the Collect a core sample of the trunk/stemtrunk/stemCore sample placed into vialCore sample placed into vialAfter equilibration time headspace is After equilibration time headspace is analyzed via GCanalyzed via GCPartition coefficients used to Partition coefficients used to determine initial concentrationsdetermine initial concentrations

Headspace Analysis

USGS

Concentration in Biomass vs. heightConcentration in Biomass vs. height

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68

10

0 2 4 6 8

TCE in tree core (ug/g)

Cor

e he

ight

(m)

Concentration decreased exponentiallywith elevation up the trunk

Modeling configurationModeling configuration

J(z+∆z)

J(z)

J( r )

C(r,z)∆r

∆zJ( r+∆r )

Tree

R

Z

Processes involved in the modelProcesses involved in the model

Chemical transport upward in xylemChemical transport upward in xylemChemical transport downward in phloemSorption/desorptionDiffusionDiffusionMetabolism

Model Prediction: distributionModel Prediction: distribution

2

4

6

8

10

12

0 5 10 15 20 25 30 35Height (cm)

TCE

con

cent

ratio

ns in

the

trans

pira

tion

stre

am (p

pm)

MeasuredModel

Model Prediction: DiffusionModel Prediction: Diffusion

00.5

11.5

22.5

3

0 5 10 15 20 25 30Height (cm)

TCE

diffu

sion

(mg/

inch

.6d)

MeasuredCalculated

Effective Diffusivity was 0.4 – 2.5 x 10-6 cm2/s

Total diffusion mass vs. influent Total diffusion mass vs. influent

Accumulative Diffusion mass, 28 day dose period

y = 0.0146x - 0.323R2 = 0.9866

y = 0.007x + 0.0443R2 = 0.9814

02468

101214

0 200 400 600 800 1000Feed Concentration, ppm

TCE

Cap

ture

d, m

g Upper Diffusion TrapsLower Diffusion Traps

Relationship to Relationship to VadoseVadose zone zone Soil 1.2 m deepSoil 1.2 m deep

R2 = 0.88

0

1

10

100

1000

10000

100000

0.1 1 10 100 1000 10000 100000 1000000

μg PCE / kg media

mg

PCE

/ kg

tree

core

Vadose Concentration

GroundwaterR2 = 0.48

Re: Garrett Struckhoff

Aberdeen Proving Ground JAberdeen Proving Ground J--FieldField

RE: Jeff Weishaar

New Haven MissouriSampled by John Schumacher USGSRolla Missouri

0

200

400

600

800

1,000

1,200

1,400

3 5 7.5 12.5 16.5

Directional variability in tetrachloroethene(PCE) concentrations in core samples collected fromtree TW28 on June 30, 2003.

HEIGHT ABOVE LAND SURFACE, IN FEET

North side of tree

South side of tree

TW28

USGS

Perhaps – directional capability in a single tree?

From:U.S.G.S. Scientific Investigations Report 2004-5049,

Recent Site InvestigationsRecent Site Investigations

1,1,2,21,1,2,2--TeCA, APG West Canal area. Heavily TeCA, APG West Canal area. Heavily Wooded area, contaminated aquifer @ 15Wooded area, contaminated aquifer @ 15--20’20’PCE in Urban Setting, much of New Haven Missouri (next slide)PAHsPAHs at Field site: at Field site: NapthaleneNapthalene, , AnthraceneAnthracene –– 2 2 othersothersRecent paper by Don Vroblesky, USGS Groundwater Monitoring and Remediation, 2004Multiple sites, basesMultiple sites, bases

Mass RemovalMass RemovalDiffusion traps placed to collect Diffusion traps placed to collect VOCs VOCs Mass collection is related to Mass collection is related to efluxeflux..Using transpiration rates of Using transpiration rates of trees, mass removal from aquifer trees, mass removal from aquifer can be estimated (under way).can be estimated (under way).

Confirmed to date: PCE, TCE, Confirmed to date: PCE, TCE, CarbonTetrachlorideCarbonTetrachloride, BTEX , BTEX (Lab), Naphthalene & PAHs(Lab), Naphthalene & PAHs

ND

7.62 μg/day

12.12 μg/day

3.66-6.35 μg/day7.36-8.68 μg/day

0.40-4.01 μg/day8.09-8.18 μg/day

11.91 μg/day

0.62-1.05 μg/day

Potential: “VOC Lift”Potential: “VOC Lift”

As As VOCsVOCs translocatetranslocate, , potential exists to diffuse potential exists to diffuse subsurface.subsurface.Enhanced Enhanced biodegradation of biodegradation of hydrocarbonshydrocarbonsRelease with organic Release with organic substrates for reductive substrates for reductive dechlorinationdechlorination

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68

10

0 2 4 6 8

TCE in tree core (ug/g)C

ore

heig

ht (m

)

SummarySummary

Tree coring for VOCs can provide site Tree coring for VOCs can provide site investigation, plume delineation for shallow GWinvestigation, plume delineation for shallow GW

Quickly, inexpensively, in tight places, easilyQuickly, inexpensively, in tight places, easily

Diffusion of VOC in phytoremediation Diffusion of VOC in phytoremediation Soil, Soil, vadosevadose zone zone VOCsVOCs are closely related to are closely related to core concentrationscore concentrationsMultiple compounds are applicable, Multiple compounds are applicable, SemiVOCsSemiVOCs

Innovative approachesInnovative approaches

Vadose Zone, VaporVadose Zone, Vapor--phase Phytoremediationphase Phytoremediation

Monitoring & detailed delineation of plumesMonitoring & detailed delineation of plumes

Groundwater management, controlling Groundwater management, controlling infiltration and promoting contaminated infiltration and promoting contaminated groundwater acquisition.groundwater acquisition.

Thank you!Thank you!

Thanks for your valued time.Thanks for your valued time.

Funding provided by : Funding provided by : National Science Foundation, National Science Foundation, EPAEPA--MHSRC, BP, Weston MHSRC, BP, Weston Solutions, US Geological Solutions, US Geological Survey.Survey.

CollaborationsCollaborations

BP (Amoco BP (Amoco –– Atlantic Richfield) Atlantic Richfield) –– Petroleum Petroleum and Chlorinated VOCsand Chlorinated VOCsVirginia Tech Virginia Tech –– Creosote, Creosote, napthalenenapthaleneUS Army US Army –– Fort Leonard Wood & Aberdeen Fort Leonard Wood & Aberdeen Proving GroundProving GroundUniversity of Washington University of Washington –– Chlorinated Chlorinated solventssolventsPro2Serve: DOE facility Pro2Serve: DOE facility –– Chlorinated SolventsChlorinated Solvents

Concete drainage ditchStorm

sewer dropbox

Concrete slab

Front Street Building

Concrete slab

Property fence

Fence post

0 20 40 60 80 100 0 20 40 60 80 100

1.5 FEET ABOVE THE LAND SURFACE 7.0 FEET ABOVE THE LAND SURFACE

PERCENTAGE OF THE MAXIMUM PCE CONCENTRATION DETECTED AT EACHHEIGHT. DIRECTION IN DEGREES FROM NORTH

Not to Scale

0O

330O

300O

270O

240O

210O180O

150O

120O

90O

60O30O TW02

0O

330O

300O

270O

240O

210O180O

150O

120O

90O

60O30O

N

Soil and soil-gassample location

Soil boring done during theremedial investigation(U.S. Environmental ProtectionAgency, 2003)

TW02

RADIAL VARIABILITY

USGS