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Analysis of Biomixtures to Determine the Fate of Pesticides

29 th Sept 2015

1Institute of Bio- and Geosciences (IBG-3), Agrosphere Institute, Forschungszentrum Jülich

GmbH, 52425 Jülich, Germany2BASF SE, 67117, Limburgerhof, Germany

3Sustainable Campus, Forschungszentrum Jülich GmbH, 52425 Jülich, Germany

Santanu Mukherjee*1, Lutz Weihermüller1, Wolfgang Tappe1, Diana Hofmann1, Stephan Köppchen1, Volker

Laabs2, Tom Schroeder2, Harry Vereecken1 and Peter Burauel3

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� Motivation

� Objectives

� Materials and Methods

� Biochar

� Digestate

�14C labelled Pesticides

� Experimental Setup

� Results from Incubation Study

� Results from Degradation Experiment

� Results from Sorption Experiment

� Take Away message

Overview

IBG-3 : Agrosphere

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Pesticides in water:sources of contamination

Diffuse Point Source

DriftDrain flowSurface flowSeepage Leaching

Tank filling Waste disposal Washings Faulty equipmentSpillages

Motivation

IBG-3 : Agrosphere

• 40,000 t of pesticides applied in Germany between 2006 and 2011(www.umweltbundesamt.de)

• Approx. > 50% of the water pollution due to leaching and mixing of pesticides from the

agriculture practices (Agrawal et al., 2010)

• Point pollution contributes approx. 40-90 % of surface and ground-water contamination

(De Wilde et. al., 2009)

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Pesticides in water:sources of contamination

Diffuse Point Source

DriftDrain flowSurface flowSeepage Leaching

Tank filling Waste disposal Washings Faulty equipmentSpillages

Motivation

IBG-3 : Agrosphere

• 40,000 t pesticides applied in Germany between 2006 and 2011 (www.umweltbundesamt.de)

• Approx. > 50% of the water pollution due to leaching and mixing of pesticides from the

agriculture practices (Agrawal et al., 2010)

• Point pollution contributes approx. 40-90% of surface and ground-water contamination

(De Wilde et al., 2009)

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• Study the fate of test compounds (Bentazone, Boscalid & Pyrimethanil)

on soils mixed with organic amendments (biochar and digestate)

Objectives

� Results should lead to improved Biofilter systems

1. Analyze the long-term stability of organic mixtures (Chapter 1)

2. Analyze the pesticide degradation behavior (Chapter 2)

3. Analyze the sorption-desorption behavior of pesticide (Chapter 3)

Biobac FranceBiomassbed Italy Biofilter Belgium Biobeds UK

IBG-3 : Agrosphere

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• Study the fate of test compounds (Bentazone, Boscalid & Pyrimethanil)

on soils mixed with organic amendments (biochar and digestate)

Objectives

� Results should lead to improved Biofilter systems

Biobac FranceBiomassbed Italy Biofilter Belgium Biobeds UK

IBG-3 : Agrosphere

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Materials

Soils

Kaldenkirchen Merzenhausen(Silt loam)(Loamy sand)

Amendments

Biochar Digestate

Pesticides

Bentazone BoscalidPyrimethanil(Herbicide) (Fungicide) (Fungicide)

Degradation potential

Leaching potential

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Pesticide Degradation Experiment

� 10 x field application of Bentazone ,

Boscalid and Pyrimethanil.

� ~ 60 % WHCmax

� CO2 trapped by NaOH

� Residue extraction using H2O /

Methanol

Incubator for Degradation Experiment (~ 25 °C)

Methods (Chapter 1)Respiration Experiment

� 2 soils and 13 different biomixtures

� Biomixtures = soil + Biochar + digestate

� Variation in % amendents

� Weekly measurements

Respirometer system

IBG-3 : Agrosphere

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Respiration Merzenhausen (silt loam)

� Not proportional degradation of C with increasing amount of digestate

� Large reduction after biochar addition

� Larger reduction for LB compared to HB

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0 10 20 30 40 50 60 70 80 900.0

1.0

2.0

3.0

4.0

5.0

day of incubation

ca

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[%C

]

control

1.0% HTB

2.5% HTB

5.0% HTB

1.0% LTB

2.5% LTB

5.0% LTB

5.0% DG

15.0% DG

30.0% DG

5% DG 1% HTB

5% DG 5% HTB

5% DG 1% LTB

5% DG 5% LTB

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

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Respiration Kaldenkirchen (loamy sand)

� Not proportional degradation of C with increasing amount of digestate

� Large reduction after biochar addition

� Higher relative degradation compared to MRZ

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0 10 20 30 40 50 60 70 80 900.0

1.0

2.0

3.0

4.0

5.0

day of incubation

ca

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[%C

]

control

1.0% HTB

2.5% HTB

5.0% HTB

1.0% LTB

2.5% LTB

5.0% LTB

5.0% DG

15.0% DG

30.0% DG

5% DG 1% HTB

5% DG 5% HTB

5% DG 1% LTB

5% DG 5% LTB

10.0

15.0

20.0

25.0

30.0

35.0

40.0

45.0

50.0

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Measurement of Dissolved Organic Carbon (DOC) and Calculation of SUVA

Sample ID Mean DOC (mg L-1) Mean UVA254 nm

(m-1) Mean SUVA

(L mg-1 m-1)

Soil (KK) 12.00 ± 2.40 21.93 ± 2.42 1.85 ± 0.16

Soil (KK) + 30% DG 50.10 ± 6.63 332.00 ± 101. 23 6.80 ± 2.88

Soil (KK) + 30% DG+ 5% Biochar 4.06 ± 0.29 5.65 ± 0.38 1.40 ± 0.08

5.89 ± 3.88 14.80 ± 11. 75 1.52 ± 1.12

Soil (KK) + 5% DG 12.20 ± 1.22 38.24 ± 12.84 3.12 ± 0.90

Soil (KK) + 5% Biochar+ 5% DG 4.13 ± 0.72 9.30 ± 1.78 2.26 ± 0.40

Soil (KK) + 5% Biochar

� 5 g of each and every following biomixtures was extracted with 10 ml 10 mM CaCl2 in horizontal shaker

for 15 min, centrifugation was done at 3210 g for 15 min

� Filtration of the supernatant was done with 0.45 µm polycarbonate filter

� SUVA (L mg-1 m-1) = UVA (cm-1) / DOC (mg L-1) * 100

IBG-3 : Agrosphere

Principle findings :

�Adsorption of DOC from digestate onto biochar surface

� Soil and Digestate mixture released max. amount of DOC

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Large reduction of C degradation when biochar added to soil / digestate mixtures

Principle Finding

Proposed Hypotheses

�Adsorption of DOC onto the biochar surface

�Chances of ammonia toxicity at higher concentration of nitrogen enriched substances

�Chemisorption of CO2 to biochar surface

�Precipitation of CO2 as mineral carbonates

�At a certain threshold, compounds from biochar could potentiallybecome microbiologically toxic

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Pesticide Degradation Experiment

� 10 x field application of Bentazone ,

Boscalid and Pyrimethanil.

� ~ 60 % WHCmax

� CO2 trapped by NaOH

� Residue extraction using H2O /

Methanol

Incubator for Degradation Experiment (~ 25 °C)

Methods (Chapter 2)Respiration Experiment

� 2 soils and 13 different biomixtures

� Biomixtures = soil + biochar + digestate

� Variation in % amendents

� Weekly measurements

Respirometer system

IBG-3 : Agrosphere

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� Highest mineralization in case of 30% DG followed by 30% DG and 5% biochar

� Lowest mineralization in case of soil and 5% biochar

� Mineralization not proportional to DG concentration

� Addition of digestate enhanced bentazone mineralization (~20%) compared to blank soil

Bentazone Mineralization (Kaldenkirchen)

Application Rate :12.80 mg kg-1 mixture

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day of incubation

% M

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%

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Pyrimethanil Mineralization (Kaldenkirchen)

Application Rate :10.67 mg kg-1 mixture

� Highest mineralization in case of 30% DG followed by 30% DG and 5% biochar

� Lowest mineralization in case of soil and 5% biochar� Mineralization not proportional to DG concentration

� Digestate enhanced pyrimethanil mineralization (~400%) compared to bare soil

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Boscalid Mineralization (Kaldenkirchen)

Application Rate :1.33 mg kg-1 mixture

� Highest mineralization in case of 30% DG followed by 30 % DG and 5 % biochar

� Lowest mineralization in case of soil and 5% biochar

� Mineralization not proportional to DG concentration

� Addition of digestate enhanced mineralization (~32%) compared to blank soil

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% M

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% of applied radioactivity after 120 days of incubation

IBG-3 : Agrosphere

13%

49%

38%

reference soil

18%9%

73%

5% DG + 5% BC

4%

50%

46%

6% 2%

92%

2%

59%

39%

Bentazone

Boscalid

Pyrimethanil

2% 3%

95%

Mineralized

Extracted

Non-extracted

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�Digestate blending with char exerted a positive effect on the mineralization rates for all pesticides

�Pesticide mineralization was not proportional to the amount of added digestate

�A 40 days of lag phase observed for pyrimethanil

Principle Findings

Proposed Hypotheses�Biochar can act as a good habitat for soil microbes

�Water extractable DOC quantity is not proportional to the digestate content

�Adaptation time needed for the microbial community

�Biochar acts as a sorbent to pesticides

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IBG-3 : Agrosphere

96 hrs 168 hrs

Soil : Solution ratios and Equilibrium time (hr) : Soil (KK)

Bentazone Bentazone

Boscalid Boscalid

Pyrimethanil

Methods (Chapter 3)

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Soil : Solution ratios and Equilibrium time (hr) : Soil (KK) + 30% DG+ 5% Char

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Soil Soil + 5% DG

Soil + 30% DG Soil + 5% DG + 5 % BC

Soil + 30% DG + 5% BC

Bentazone sorption-desorption

(Kaldenkirchen)

IBG-3 : Agrosphere

� Higher KOC and Kd values for biochar

and digestate based mixtures

� 1/nf <1

� 30% DG showed higher sorption

affinity than reference soil and 5%

DG mixture (higher KL and Smax

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Soil + 5% DG

Soil + 5% DG + 5 % BC

Soil + 30% DG + 5% BC

Boscalid sorption-desorption

(Kaldenkirchen)

Soil

Soil + 30 % DG

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Soil Soil + 5% DG

Soil + 5% DG + 5 % BC

Soil + 30% DG + 5% BC

Pyrimethanil sorption-desorption

(Kaldenkirchen)

Soil + 30% DG

IBG-3 : Agrosphere

� Higher KOC and Kd, Kf and KL values for

biochar and digestate based mixtures.

� 1/nf <1

� Kfdes < Kfads

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�Kd and KOC values were higher for hydrophobic pesticides

�L-type sorption isotherms observed mostly for all soil and digestate based mixtures (1/nf <1) and C-type (1/nf ~1) for biochar and digestate based mixtuIn general, 1/nfdes << 1/nfads observed.

�Lower DOC content of biochar and digestate mixture enhanced sorption

Principle Findings

Proposed Hypotheses�Higher organic C content attributed to the enhanced sorption

�Water extractable DOC competes for the sorption sites

�Highest lignin content of 30% DG mixture enhanced bentazone and pyrimethanil sorption

�Stronger retention lead to difficulties in desorption of hydrophobic pesticide

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�C degradation is not proportional to the input of the digestate

(in respiration study)

�Biochar reduces C degradation from soil/digestate mixture (in

respiration study)

�Mixture of biochar & digestate = highest pesticide

mineralization

�Biochar adddition reduces pesticide mineralization

�Biochar showed largest NE residues followed by mixture of

char & digestate

�Stronger retention of the hydrophobic pesticides observed in

the biomixtures

Take away message

� Mixture of char & digestate most appropriate (5% DG and 5% BC) IBG-3 : Agrosphere

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IBG-3 : Agrosphere

Publications�Mukherjee, S., Weihermueller, L., Tappe, W., Vereecken, H., Burauel, P., 2015. Microbial respiration of biochar and digestate based mixtures. Biology and Fertility of Soils (Published)- Chapter 1

�Mukherjee, S., Tappe, W., Weihermueller, L., Hofmann, D., Köppchen, S., Laabs, V., Schroeder, T., Vereecken, H., Burauel, P., 2015. Dissipation of contrasting pesticides in biochar and digestate based soil mixtures for biopurification systems. Science of the total Environment (Submitted)-Chapter 2

�Mukherjee, S., Weihermueller, L., Tappe, W., Hofmann, D., Köppchen, S., Laabs, V., Schroeder, T., Vereecken, H., Burauel, P., 2015. Sorption-desorption behaviour of Pesticides in biochar and digestate based soil mixtures for biopurification systems (under preparation) - Chapter 3

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Acknowledgements

Ulrich Disko

Sirgit Kummer

Martina Krause

Andrea Kubica

IBG-3 : Agrosphere

Mitglied der Helmholtz-Gemeinschaft

IBG

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Degradation Experiment Set up :

Field rate of application of Bentazone : 960 g/ha

Rate of application in Experiment : 12.80 µg/g soil mixtures

(B.D = 1.5 g/cm3 , Soil layer = top 1 cm )

Thermostat Incubator for Degradation Set up ( Temp. ~ 25 °C)

Water content of biomixture ~ 60 % of WHC max.

Total Applied Radioactivity/3.15 kg biomixture : 1.52 MBq ± 0.04

Evolution of 14 CO2 as a product of mineralization is measured by 1.5 ml 2 M NaOH

solution .

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Some features of Test Substances proposed for Degradation Study :

Characters Bentazone Boscalid Pyrimethanil

Type Herbicide Fungicide Fungicide

Chemical Group Benzothiazone Carboxamide Anilopyrimidine

Water Solubility

(mg/L)

570 4.6 121

Principle metabolite n-methyl bentazone NA 2-amino-4,6-methyl

pyrimidine

Proposed

pesticide/soil

mixture (mg/100g

dry mass basis )

1.28 0.133 1.067

Proposed

radioactivity (kBq)

46.85 6.66 224.7

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Some useful informations about Sorbents:

Materials Soil 1 Soil 2 BC400 BC 800 Digestate

Source /place and texture Kaldenkirchen (loamy sand)

Merzenhausen (silty loam)

Woodchips§ Woodchips§§ Maize-silage, Chicken manure and Beef waste

pH 5.7* 7.0* n.d n.d n.d

CEC(cmolc kg-1) 7.8* 11.4* n.d n.d n.d

COC (%) 1.07* 1.24* 75.9§ 74.4§§ 40

H

_ _

1.64§ 0.5§§

_

O

_ _

5.05§ 10.6§§

_

H/C Atomic Ratio

_ _

0.26 0.08

_

O/C Atomic Ratio

_ _

0.05 0.11

_

Surface Area (N2) (m2/g) n.d n.d 231 225 3.09

Surface Area (CO2) (m2/g) n.d n.d 634 625 37.90

Micropore volume (cc/g)

_ _

0.22 0.21 0.01

*(Kasteel et. al. , 2010), §(Carbon Terra, 2011) and §§(Pyreg, 2011)

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Digestate : Solid material remaining after the anaerobic digestion of a biodegradable

feedstock.

Fiber: Solid fraction of digestate with low nutrients

- used as soil conditioner

(http://en.planet-biogas.de)

Approx. Elemental Composition On Dry Matter Basis

(g/kg )

* Wheat Straw *Solid Digestate

Organic C 429 404

Total N 5.6 93

Lignin 177 200

C/N 76.6 4.34

Selected characteristics of the Straw and Digestate:

*(Tambone et. al., 2009)

IBG-3 : Agrosphere