Why we need upscaling to describe microbiological processes in groundwater: Examples from fractured porous media and bioaugmentation technologies

P.J. Binning

Two problems where upscaling is needed

Bioaugmentation

Enhanced biodegradation in clays

Pesticide contamination of groundwater

GEUS, 2006, 2009

% W

ater

sup

ply

wel

ls w

ith p

estic

ides

Non detect

0 %

100 %

“the technique for improvement of the capacity of a contaminated matrix (...) to remove pollution by the introduction of specific competent strains or consortia of microorganisms”(El Fantroussi and Agathos, Curr. Opin. Microbiol. 2005)

liquid microbial culture immobilized

microbes

activated soil microbes with mobile genes rhizosphere

biaogumentation

Boldt et al. 2004

phyto-augmentation

Shimidzu et al. 2002

Bioaugmentation

Immobilized microbes

Time (day)

0 5 10 15 20 25 30

Sim

azin

e (m

g kg

-1)

020406080

100120

• simazine, agricultural soil• 50% water saturation• 2-mm alginate beads• Pseudomonas sp. MHP41

Morgante et al. (2010) FEMS Microbiol. Ecol. 71:114-126

Data

Model

Linuron

Herbicide used since 1965, now banned in 7 of 27 EU countries

Suspected developmental or reproductive toxin

First-order mineralization rate

Time (h)

0 96 192 288 384 480

14C

O2 (

% o

f ini

tial 14

C)

0

20

40

60

80

100

( )ktCC −= exp0

k=0.216 day-1

Reaction time scales about 5 days

Variovorax sp. SRS16

Diffusive transport

0)()(=+∇+•∇−

∂+∂

wwwaHwwaHw kCCK

tCK θθθθθ

aw DD

Expected diffusive time scales17 days for 20mm bead separation

Mineralization time scale

Bead spacing (mm)

5 10 15 20 25 30

Tim

e (d

ay)

102

103

104

105

106

100%35%10%

90% removal, 2mm beads

1 year

20 years

saturation

, ,w b b w s sb s eff

b s b s

m V m Vdm k k k mdt V V V V

θ θ= − − = −

+ +

, ,w b b b w s s seff

b s

k V k Vk

V Vθ θ+

=+

( )tkmm eff−= exp0

A simple mixing model

sV

bVFor Vb/(Vs+Vb)=1% reaction rate reduced by a factor of 100

Bead spacing (mm)

0 20 40 60 80 100

k eff

(day

-1)

10-7

10-6

10-5

10-4

10-3

10-2

10-1

100

t 90%

(day

)

100

101

102

103

104

105

106

Simple mixing model

Degradation rate in beads

Degradation rate for soil

effk 90t

2mm beads, 100% saturation

Application of technologyRequire ~24 tons 2mm beads for 1 ha to remove 90% linuron in 100 days

(spaced at <10 mm in a layer of 100 mm)

ww

w.g

eogr

aph.

org.

uk/p

hoto

/393

25

Effect of water infiltration

0)()(=+

∂∂

+∇+•∇−∂

+∂ww

wwwaHw

waHw kCz

CqCKt

CK θθθθθaw DD

Effect of water infiltration

Bead spacing (mm)

5 10 15 20 25 30

C/C

0

0,0

0,2

0,4

0,6

0,8

1,0

100%35% 10%

column 18.5 cm

Reduction in outlet concentration

100%35% 10%

Saturation

Increasing column length, decreasing

bead density

mineralization rate predicted by the model(% of benzoate mineralized per day)

0.0 0.5 1.0 1.5 2.0 2.5 3.0

expe

rimen

tal m

iner

aliz

atio

n ra

te(%

of b

enzo

ate

min

eral

ized

per

day

)

0

10

20

30

40

50

60

70

7%27%68%

Effect of cell dispersal

Dechesne et al. (2010) Env. Sci. Technol. 44:2386-2392

full colonization=bugs everywhere

minor colonization=bugs in beads

Conclusions

Bioaugmentation has poorer performance in field than expected from lab results

Models developed to predict field performance• Simple Mixing Models: Can upscaling help here?• Process models

Soil moisture, infiltration and other environmental conditions affect performance

Cell dispersal may potentially improve the technology (observed in sand, but limited in soil)

Sand aquiferChalk aquifer

Clayey till

DTU og Orbicon

Enhanced biodegradation in clays

•Long term secondary source of contamination!

•Remediation of chlorinated solvents?

•Stimulated Reductive Dechlorination, SRD?

Geological characterizationGeostatistical toolsHydrogeological model

Modeling ofSRD in clay till

Optimization of enhancementSpreading of reagentsInjection methods

Remediation designPractical tools

Microbial and chemical process understanding

Biogeochemical site characterization

What do clays look like?

Christiansen et al. (2008). ES&T, 42, 570–576.

Fracture mapping

Sand lenses

Fracture distribution – Field data

SprækkeJAGG, 2008Klint, 2001, PhD Thesis

Cumulative fracture spacing (average distance between vertical/sub-vertical fractures)

Dep

th m

belo

w g

rou

nd

su

rface

(m

)Silstrup

Haslev 1

Gedser

Flakkebjerg

Avedøre

Havdrup

Fårdrup

Lillebæk

Ranzausgade

Slæggerup

Ringe

Haslev 2

Kamstrup

Estrup

Mammen

Grundfør

Højstrup 2HøjstrupGjorslev

TuneSigerslev 1

Sigerslev 2

Vasby

Location0 0,5 1 1,5 2 2,5 3 m

0

0.5

11.5

2

2.5

3

3.5

44.5

5

5.5

6

6.5

77.5

8

8.5

1

2

3

1

2

3

Anaerobic dechlorination

Only Dehalococcoides

species

Various microorganisms

Model system - simplification

Model developed in Comsol Multiphysics

ERD injection of donor and bacteria

fractures

Injection depths

Contaminant mass in matrixSum of chlorinated ethenes: TCE, DCE and VC

Mass in matrix

Full scale application of enhanced reductive dechlorination in clayey till (Sortebrovej, Denmark)

Anaerobic dechlorination associated with sandstringers in clayey till

14,2

14,3

14,4

14,5

14,6

14,7

0 1 2 3 4 5 6 7 8Chlorinated ethenes [mg/kg]

Dep

th [m

bgs

.]

TCE cis-DCE VC Ethen

Clay core

Modeling - scenarios

Injection of donor in high permeability conduitsSpecific degraders only related to sandstringers or fracturesReaction zones surrrounding sandstringers

Base line – no dechlorinationRZ10 – 10 cm reaction zoneRZ30 – 30 cm reaction zoneRZ60 – 60 cm reaction zoneBest case – entire matrix1 m

Generation of degradationproducts – treatment area

RZ305 year after start of remediation

Before remediation

Comparison with field data

Degree of dechlorination 2 years after remediation

Mass of contaminants in treatment area

Start of remediation at day 0

Case study challenges:

How do we model geology?

How do we model hydraulics, including injection of substrate?

Where are the bugs?

How do we model the biogeochemistry?

AcknowledgementsPart 1M. Owsianiak, A. Dechesne, B.F. SmetsMikołaj Owsianiak, Arnaud Dechesne, Philip J. Binning, Julie C. Chambon, Sebastian R. Sørensen, Barth F. Smets, Evaluation of Bioaugmentation with Entrapped Degrading Cells as a Soil Remediation Technology, Environmental Science and Technology, 44, 19, 7622-7626, doi: 10.1021/es101160u, 2010.

Part 2Julie Chambon, Gabriel Manoli, Philip Binning, Ida Damgaard, Mette Broholm, Camilla Christiansen, Gitte Lemming, Poul L. BjergJulie C. Chambon, Mette M. Broholm, Philip J. Binning and Poul L. Bjerg, Modeling multi-component transport and enhanced anaerobic dechlorination processes in a single fracture – clay matrix system, Journal of Contaminant Hydrology,112, 1-4, 77-90, 2010.