Controlling parameters for microbial pesticide degradation in

1

Institute of Environment & Resources Technical University of DenmarkH.-J. Albrechtsen

Controlling parameters for mControlling parameters for microbial icrobial pesticide degradation in pesticide degradation in subsurface and aquiferssubsurface and aquifers

Hans-Jørgen Albrechtsen

Liselotte Clausen, Philip G. Pedersen, Lars Toräng, Nina Tuxen, Niels Nyholm, Poul L. Bjerg,

Gry S. Janniche, Ellinor Lindberg, Christophe Mouvet

Warwick, 28 March 2006

Institute of Environment & Resources DTUTechnical University of Denmarkwww.er.dtu.dk / [email protected]


BackgroundBackgroundPesticides and degradation products are detected in an increasing number of aquifers all over the world, including Europe

Aquifer environments differ in many ways from topsoilLow concentrations of the pesticides

EU guideline: 0.1 µg/L

Low content of organic matter – effect on sorption

Low microbial numbers, densities and activities

Considering hydraulic residence times in aquifers of 30-60 years, half-lives of e.g. 10 years would still be relevant

AIM: Identify controlling parameters to be considered, when predicting the fate of pesticides in subsurface and aquifers

2


LTHE (Grenoble, France)CCBF (Perugia, Italy)

WRc (Medmenham, England)C3ED (Versailles, France)DTU (Lyngby, Denmark)

BRGM (Orléans, France)FZJ (Jülich, Germany)

Alterra (Wageningen, Holland)SLU (Uppsala, Sweden)

UKBH (Copenhagen, Denmark)EPFL (Lausanne, Switzerland)

Sampling in Denmark

EU’s 5th Framework Programme, key action water

PEGASE

Pesticides in European Groundwaters : detailed study of representative Aquifers and Simulation of possible Evolution

Sampling in Switzerland


Pesticides and aquifersPesticides and aquifers

Aquifers: Key pesticides:

Havdrup

Krauthausen

MartignyBrévilles

N N

NCl NHCH2CH3

NHCH(CH3)2

Cl

CH3

OCHCO2H

CH3

NHCON(CH3)2(CH3)2CH

Atrazine

MCPP Isoproturon

Deethylatrazine

N N

NCl NH2

NHCH(CH3)2

CH3

N

CH2CH3

CH2OCH2CH3

COCH2Cl

Acetochlor

Atrazine Deethylatrazine

MCPP Isoproturon

Acetochlor

3

DTU

3 cm

C2, 3.15 – 3.45 m 70 cm

Calcaire brun, fin, lité (mudstone); bioturbations (terriers) remplies de sédiments blancs

Niveau très fossilifère, poreux. Type Packstone

Calcaire fin beige, recristallisé sur les plans de fracturation, parfois poreux, souvent complètement cimenté

2 cm 2 cm 7 cm 10 cm6 cm 2 cm12 cm 5 cm


Delicate handling of sediment samplesDelicate handling of sediment samples

4


Degradation: Unsaturated zoneDegradation: Unsaturated zonePurpose:Mineralization of pesticides in depth profiles

Methods:Set up:

33 g dry sediment, 0.70-10.64 mL water (natural water content)

0.5 mL 14C-labelled pesticide added. Initial concentration 10 µg/kg

Measurements:14CO2 trapped in 2 mL 0.5 M sodium hydroxide


Brévilles: Sediment C1, unsaturated

0-0.25 0.25-0.40 3.10-3.25 6.0-6.25 9.0-9.12 13.0-13.12 mbs

5


Brévilles: Unsaturated zoneBrévilles: Unsaturated zone

Well C1, topsoil

0

5

10

15

20

25

30

35

40

0 10 20 30 40 50 60 70Days

14C

O2 (

% o

f ini

tial 14

C) MCPP

Isoproturon

Acetochlor

AtrazineDea


Brévilles: Unsaturated zoneBrévilles: Unsaturated zone

6


Brévilles: Unsaturated zone, C2


ConcentrationConcentration

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Degradation of 2,4Degradation of 2,4--D D aerobic, aquifer sediment, 10°Caerobic, aquifer sediment, 10°C

Change axis scale

% 14

C re

mai

ning

Con

cent

ratio

n (µ

g/L)

Toräng et al., 2003, ES&T


ConcentrationConcentration

IS IMPORTANT

Kinetics may shift depending of concentration (µg/L)Thresholds: Above: faster, growth based

Below: slower, non-growth based

Implications:Degradation experiments to estimate rates should becarried out at relevant (low) concentrations

Results from top soil cannot be transferred to subsurface

Results from contaminated sites (higher concentrations) cannot be transferred to ’non-contaminated’ aquifers (lower concentrations)

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ExposureExposure

How much – over time?


Field injection experimentField injection experiment• Aquifer

– Unconfined– Aerobic

• Injection– Natural gradient– Continuous injection for

216 days– 40 µg/L of MCPP and

dichlorprop

• Sampling– At least every second

week

Broholm et al., 2001, WWR

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Tuxen et al., 2002, ES&T



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Institute of Environment & Resources Technical University of DenmarkH.-J. Albrechtsen de Lipthay et al. (2003), AEM, 69, 461-467


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2,4-D2,4-D

degraders

Total bacteria

Bio

mas

s (c

ells

/g)

Con

cent

ratio

n ( µ

g/L)


2,42,4--D, specific degraders (D, specific degraders (1414CC--MPN) MPN) Total bacterial counts (AODCTotal bacterial counts (AODC--staining)staining)

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Degradation of 2,4Degradation of 2,4--DDSpecific and total bacteriaSpecific and total bacteria

Unpolluted aquiferUnpolluted aquifer

(Shown on the previous slide)


Initial conc. 0 µg/L 1 µg/L 100 µg/L (=0.45 µM)


Degradation of 2,4Degradation of 2,4--D D Specific and total bacteria Specific and total bacteria

Weakly preWeakly pre--exposed aquiferexposed aquifer



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Degradation of 2,4Degradation of 2,4--D D Specific and total bacteria Specific and total bacteria

Highly preHighly pre--exposed aquiferexposed aquifer




Redox conditionsRedox conditions

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Effect of oxygenEffect of oxygenHavdrupHavdrup, MCPP, MCPP

MC

PP C

/C0

1.0

0.8

0.6

0.4

0.2

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

Days

Havdrup (Ha-A) Anaerobic



MC

PP C

/C0

Days

1.0

0.8

0.6

0.4

0.2

1.0

0.8

0.6

0.4

0.2

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

Havdrup (Ha-D) Anaerobic

Havdrup (Ha-A) Anaerobic

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MC

PP C

/C0

Days

1.0

0.8

0.6

0.4

0.2

1.0

0.8

0.6

0.4

0.2

1.0

0.8

0.6

0.4

0.2

0 100 200 300 0 100 200 300

1.0

0.8

0.6

0.4

0.2

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

0,0

0,2

0,4

0,6

0,8

1,0

0 200 400 6000,0

0,2

0,4

0,6

0,8

1,0

0 200 400 600

Havdrup (Ha-D) Anaerobic Havdrup (Ha-D) +Oxygen

Havdrup (Ha-A) Anaerobic Havdrup (Ha-A) +Oxygen


Effects of oxygen

concentration on degradation

Tuxen et al., 2006, GWMR

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SorptionSorptionPurpose:

Determine (Kd) parameters for modelling purposes

Investigate sorption ranges within and between aquifers

Investigate the interactions between sorption and degradation

Methods:Batch experiments: 5 mL water. 5 g sediment. 10°C. Concentrations: 50 µg/L

Equilibrium time: 7 days (MCPP, acetochlor), 14 days (atrazine, deethylatrazine, isoproturon)

Measurements: 14C-pesticide and 14CO2


BV 1

8.4-

18.7

BV-1

8.5-

18.9

BV-

22.6

-22.

9

BV

38.

5-38

.7

BV

39.

0-39

.3

BV 4

6.8-

47.1

KR

-A 1

.7-1

.9

KR

-B 1

.7-1

.9

Ma-

A 2.

5-3.

1

Ma-

B 2

.5-3

.0

(Ha-

A)

(Ha-

B)

MCPPDeethylatrazine

AtrazineIsoproturon

Acetochlor0.00.51.01.52.02.53.03.54.04.55.0 MCPP

DeethylatrazineAtrazineIsoproturonAcetochlor

Sorption coefficients (Sorption coefficients (KKdd= C= Css//CCeqeq))

Anaerobic

TOC: 0.01-0.06%Ma ~0.5%

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Spatial variationSpatial variation


Brévilles 38.71- 38.91 mbs. (Pz 1)

0,0

0,2

0,4

0,6

0,8

1,0

0 50 100 150 200 250 300 350

Days

MC

PP C

/C0

38.71-38.75

38.75-38.79

38.79-38.83

38.83-38.87

38.87-38.91

Small scale variation Small scale variation Degradation: MCPPDegradation: MCPP

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Phenoxy acids

MCPP

MCPP

Significant plume of phenoxy acids

Tuxen et al., 2005

Degradation across the fringe

VariablesOxygenPhenoxy acid conc.Specific biomass

Tuxen et al., 2005

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Quantification of Quantification of tfdAtfdA, , tfdBtfdB and and tfdCtfdCin 50 aquifer sediment samplesin 50 aquifer sediment samples

tfdA: 102 – 103/g sediment in 3 samples (tfdA 100% match with R. eutrophaJMP134 tfdA)

tfdC: 102/g sediment in same 3 samples

tfdB: below detection limit

=> tfdA,C presence, but generally not correlated with MPN

36.5

37

37.5

38

38.5

39

39.5

0 1000 2000 3000 4000

#/g sediment

leve

l (m

)

tfdA tfdC specific degraders (MPN)

Lindberg et al., 2006


Controlling parameters in subsurfaceControlling parameters in subsurface

Concentration influences kinetics – even at very low concentrations (µg/L)

Exposure (µg/L) increases degradation

Spatial variation (cm) is not always just stochasticSearch for controlling parameters:

Redox, concentration

Degradation may leave a footprint or a trace in the microbial population

Tfd-genes

Composition of microbial populations

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Nnn

PEGASE

Funding Funding –– thanks tothanks to


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Coupe géologique n°3

PZ8 et 5

PZ7

PZ3

PZ1

140

80

120

100

60200 1200 1400400 600 800 1000

Distance (m)



Station hydrométrique

Source des Brévilles

PZ6

PZ7

PZ4

PZ2140

80

120

100

60

140

80

120

100

60

Alti

tude

NG

F (m

)

200 1200 1400400 600 800 1000

200 1200 1400400 600 800 1000

Niveau piézométrique le 20/02/01

le 14/05/03

SPRING

Water table

Discontinuous clay layer

BRGM

BrévillesBrévilles

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Effect of exposureEffect of exposure


(GEUS, 2003)

Detection of pesticides in water

supply wells in Denmark 1992-2002

> 0.1 µg/L

0.01-0.1 µg/L

0 50 km

Detection of pesticides in water Detection of pesticides in water supply wells in Denmark 1992supply wells in Denmark 1992--20022002

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Investigation period: 1993-1995Pesticides present

in 54% of the 1034 sites sampledin both agricultural (56%) and urban (47%) settings

39 pesticides detected of the 46 examinedTop 5:

Atrazine (38%) - 18% > 0.1 µg/LDeethylatrazine (34%) – metaboliteSimazine (18%)Metolachlor (15%)Prometon (14%) – urban area

Sites with pesticides: 73% ≥ 2 pesticides (25% ≥ 4)

Pesticides in groundwater, USAPesticides in groundwater, USA

Kolpin et al., 1998, ES&T


Danish aquifer sediments Danish aquifer sediments concentration after 1 year incubationconcentration after 1 year incubation

P.G. Pedersen, Thesis

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Zone of degradation at fringe?

Sediment core5 cm pieces50 microcosms

Tuxen et al., 2005


Microcosm studies

Oxygen control14C-labelled MCPPEvolved 14CO2

Tuxen et al., 2005

Documents

Controlling parameters for microbial pesticide degradation in