Mathieu ETIENNE

CNRS - Université de Lorraine, LCPME, Nancy, Francemathieu.etienne@univ-lorraine.fr

Laboratoire de Chimie Physique et Microbiologie pour les Matériaux et l’EnvironnementUMR 7564, CNRS – Université de Lorraine,405, rue de Vandoeuvre, 54600 Villers-lès-Nancy, France.

1

Processus électromicrobiologiques pour le traitement des eaux

Journées de Promotion Procédés Produits (J3P)2018 – Procédés électrochimiques avancés pour le traitement des eaux – Jeudi 5 Juilletcampus de l’Ensic, Nancy, 1 rue Grandville 54000 Nanc

• Biofilm is an organized bacteria community embedded in autoproducedextracellular polymeric substances and fixed on a support

2

• About 109 bacteria cells by cm3 of biofilm

• Found on many type of surfaces : living tissues, sols, metals or chirurgical devices, …

Biofilm E. coli, Ch. Beloin, J.-M. Ghigo, Instit. Pasteur Paris

Biofilm E. coli, B.A. Annous and al., Food Science 2009

Biofilm

• Present a problem of diseases riskin hospital and contamination infood storage

• Many beneficial applications in environment as biodepollution, water treatment and energy production in microbial fuel cell

3

S. Pinck, F. Jorand, M. Etienne, Electrochemistry of Biofilms, in: Ref. Modul. Chem. Mol. Sci. Chem. Eng., Elsevier, 2017. doi:10.1016/B978-0-12-409547-2.13805-3.

Extracellular electron transfer in electroactive biofilm

CymA

MtrA

MtrB

MtrCOmcA OmcA

Electrodee - e -

e -

e -

e -

OM

PS

IMMenaquinol pool

Outer membrane

Periplasme

Inner membrane

Shewanella oneidensis

S. Pinck, F.P.A. Jorand, M. Etienne, Electrochemistry of Biofilms, in: Encycl. Interfacial Chem. Surf. Sci. Electrochem., 2017. doi:10.1016/B978-0-12-409547-2.13805-3.

• Shewanella oneidensis MR-1 as electroactive bacteria

• c1 from bovin heart as electron shuttle

• Multi-walled carbon nanotubes (MWCNT) as conductive nanowire

ELECTRODE

Living & conductivebiocomposite

Formate CO2

CNT

Cytochrome cBacteria

e-

5

MWCNT

S. Pinck, M. Etienne, M. Dossot, F.P.A. Jorand, A rapid and simple protocol to prepare a living biocomposite that mimics electroactive biofilms, Bioelectrochemistry. 118 (2017) 131–138. doi:10.1016/j.bioelechem.2017.07.010.

The system that we have studied

2 µm 2 µm 2 µm

A B C

In the suspension On a glassy carbon electrode

ELECTRODE

Living & conductivebiocomposite

Formate CO2

CNT

Cytochrome cBacteria

e-

A biofilm-like biocomposite

7

MWCNT

c1

Extracellular space

Outer membrane

Periplasmic space

Inner membrane

Cytoplasm

Oxidation of formate: bioanode

8

50 mV.s-1

S. oneidensis MR-1MWCNTand c1

Electrochemical responses of the biocomposites

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6-8

-6

-4

-2

0

2

4

6

8

J /

µA

cm

-2

E vs. Ag/AgCl / V

9

50 mV.s-1

S. oneidensis MR-1MWCNTand c1

in presence of 0.3 mM formate

Electrochemical responses of the biocomposites

-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6-8

-6

-4

-2

0

2

4

6

8

J /

µA

cm

-2

E vs. Ag/AgCl / V

10

Reduction of fumarate: biocathode

MWCNT

Exogenous cytochromeExtracellular space

Outer membrane

Periplasmic space

Inner membrane

Cytoplasm

11

5 mV.s1

Electrochemical responses of the biocompositesMade with Shewanella oneidensis, MWCNT and c3 Desulfovibrio vulgaris Hildenborough

-500 0 500

-250

-200

-150

-100

-50

0

50

100

150

I /

µA

E vs. SHE / mV

no fumarate

50 mM fumarate

S. Pinck, M. Xu, R. Clément, E. Lojou, F.P.A. Jorand, M. Etienne, Influence of cytochrome charge and potentialon the cathodic current of electroactive artificial biofilms, Bioelectrochemistry. (2018) under revision.

Anaerobic electron transfer pathways

Y. Chen, F. Wang, Front. Mar. Sci. 2015, 1, 1–9.

K. Rabaey, R.A. Rozendal, Microbial electrosynthesis - revisiting the electrical route for microbialproduction., Nat. Rev. Microbiol. 8 (2010) 706–16. doi:10.1038/nrmicro2422.

E versus SHE

Standard electrode potential calculated from Gibbs free energy data

The purpose of nitrate removal

EU regulations[1]:

• 50 mg/l of nitrate

• 0,5 mg/l of nitrite

• The following condition must be achieved:

[nitrate]/50 + [nitrite]/3 ≤ 1

However, water with >25 mg/l of nitrate should already be purified.[2]

USA regulations[3]:

• 10 mg/l of nitrate

• 1 mg/l of nitrite

The water intended for human consumption may contain maximum: The effects of too high concentration of nitrate:

On humans:

• Methemoglobinemia (blue baby syndrome)

• Carcinogenicity (gastric cancer)

On animals:

• Bad flavor and taste as well as toxic effect on fish

On the environment:

• Eutrophication of lakes and rivers[4]

[1]: COUNCIL DIRECTIVE 98/83/EC of 3 November 1998 on the quality of water intended for human consumption[2]: E. France, Pratiques agricoles et nitrates dans les milieux aquatiques, Collect. Les Syntheses 11 (2014) 16.[3]: United States Environmental Protection Agency (USEPA), 2009. EPA 816-F-09-004: National Primary Drinking Water Regulations Table.[4]: Ghafari, S., Hasan, M., Aroua, M. K., 2008 Bio-electrochemical removal of nitrate from water and wastewater—A review, Bioresour. Technol. 99, 3965-3974

Four reduction steps towards nitrogen gas (N2)[1]

• 𝑁𝑂3− + 2 𝑒− + 2 𝐻+ → 𝑁𝑂2

− + 𝐻2𝑂

𝐸°′ = +0,433 𝑉 𝑣𝑠 𝑆𝐻𝐸

• 𝑁𝑂2− + 𝑒− + 2 𝐻+ → 𝑁𝑂 + 𝐻2𝑂

𝐸°′ = +0,350 𝑉 𝑣𝑠 𝑆𝐻𝐸

• 𝑁𝑂 + 𝑒− + 𝐻+ → 1 2𝑁2𝑂 + 1 2𝐻2𝑂

𝐸°′ = +1,175 𝑉 𝑣𝑠 𝑆𝐻𝐸

• 1 2𝑁2𝑂 + 𝑒− + 𝐻+ → 1 2𝑵𝟐 + 1 2𝐻2𝑂

𝐸°′ = +1,355 𝑉 𝑣𝑠 𝑆𝐻𝐸

In total, 2 moles of nitrate and 10 moles of electrons per 1 mole of gas nitrogen (N2) are used:

• 2 𝑁𝑂3− + 10 𝑒− + 12 𝐻+ → 𝑁2 + 6 𝐻2𝑂

[1]: Clauwaert, P., Verstraete, W. et al., 2007, Biological Denitrification in Microbial Fuel Cells, Environ. Sci. Technol. 41, 3354-3360.

Microbial fuel celL

Organic matter

CO2

Cathode

e- e-

H+

PEM

Anode

O2

H2O

resistor

Air sparger

multimeter computer

Logan, B., Microbial Fuel Cells, John Wiley and Sons Inc, Hoboken, New Jersey, 2008.

Anodicbiofilm

Microbial fuel Cell for denitrification

Organic matter

CO2

resistor

e- e-

H+

PEM

Anode

NO3-

NO2-

N2

Cathode

Anodic biofilm

Cathodic biofilm

multimeter computer

Sediment microbial fuel cell

Aerobic zone - water

Anaerobic zone - sedimentSediment CO2

O2 H2O

H+ resistor

e-

e-Zabihallahpoor, A., Rahimnejad, M.,Talebniaab, F., 2015, Sedimentmicrobial fuel cells as a new source ofrenewable and sustainable energy:present status and future prospects,RSC Adv. 5, 94171-94183.

Microbial electrochemical snorkel

Aerobic zone - water

Anaerobic zone

Organics

CO2

O2

H2O

B. Erable, L. Etcheverry, A. Bergel, From microbial fuel cell (MFC) to microbialelectrochemical snorkel (MES): maximizing chemical oxygen demand (COD) removal from wastewater., Biofouling. 27 (2011) 319–326. doi:10.1080/08927014.2011.564615.

The quantitative objective is to double the denitrification rate which is in Rampillon typically

below 350 mg of N-NO3/m2/day

Low Nitrate ANR project: to fasten the denitrification in the wetland of Rampillon with electromicrobiology

Conclusions (suite à la table ronde)

L’électromicrobiologie donne l’opportunité de coupler les processus électrochimiques et microbiologique pour le traitement des eaux

Les verrous principaux verrous pour son application hors des laboratoires est la faible conductivité des solutions (mS/cm) et une densité de courant relativement faible (A/m2)

Les processus bioanodiques sont maintenant assez bien connus

Les opportunités se situes du côté des processus biocathodiques pour favoriser des processus de dénitrification, de production de biohydrogène ou encore la récupération de métaux à forte valeur

Intérêt industriel pour les biopiles microbiennes, qui donneraient des opportunités d’innovation dans la filière traitement d’eau

AcknowledgementsLCPME

Alain WalcariusManuel Dossot

Mengjie XuL2CM

Marie-Jo StébéBIP: Elisabth Lojou, Romain Clément

LowNitrate project, ANR-17-CE04-0004 Joanna Roginska (LCPME)Frédéric Jorand (LCPME)

Christelle Despas (LCPME)Claire Genois (LCPME)

Julien Tournebize (IRSTEA)Théodore Bouchez (IRSTEA)

Alain Bergel (LGC) Frédéric Barrière (ISCR)

Thank you very much for your kind attention