Titre : Interrelationship between cathodic protection and microbiologically influenced corrosion in marine environment: brief-review and prospects
Année : 2003
Auteur(s) : Pineau S. Dupont-Morral I. Braisaz T.
Abstract : Cathodic protection is widely used to prevent corrosion of steel constructions exposed to seawater. This protection causes a calcareous deposit as well as a biofilm formation. The Sulphate-Reducing Bacteria (SRB) and Thiosulphate-Reducing Bacteria (TRB) are involved in the steel biodegradation phenomena in marine environment. The surface colonization by these species under cathodic protection are described particularly for the TRB and with immersion periods of over 30 days. After a brief-review, preliminary studies explain the first results of our investigation in natural seawater and carbon steel during 4 to 8 weeks experiment. We have made experiments with natural strains of SRB/TRB, with monoculture of Desulfovibrio halophilus (SRB) and Dethiosulfovibrio peptidovorans (TRB), with potential a Cathodic Protection (CP) of –900 mV/SCE and –1000 mV/SCE and without CP. These results seem indicate that the effects of CP on the sulphide-producing bacteria metabolism is the reduction of their corrosive activity.
Harbour Congress Proceeding, Antwerpen-Belgium, March-April 2003. Proceedings p.169-178
Titre : Impact de la protection cathodique sur l’activité corrosive de la flore sulfurogène
Année : 2003
Auteur(s) : Pineau S. Lefèvre Y. Dupont-Morral I.
Abstract : La protection cathodique (PC) de l’acier au carbone en milieu marin est connue pour son effet inhibiteur vis-à-vis de la colonisation des genres bactériens aérobies [1]. En revanche, il a été démontré qu’un potentiel compris entre -900 mV/ECS et -1000 mV/ECS (généralement appliqué en zones portuaires françaises) est sans effet limitant vis-à-vis de la colonisation de la flore anaérobie de type sulfurogène telles que les Bactéries Sulfato-Réductrices (BSR) et Thiosulfato-Réductrices (BTR) [2][3][4][5]. Lors d’essais en laboratoire, il a été démontré que la rupture du système de PC accélère les phénomènes de biodétérioration, alors que ceux-ci semblent inhibés en temps normal [3][6]. Par conséquent, la PC modifierait le métabolisme bactérien et/ou l’action du produit du métabolisme bactérien. Plusieurs hypothèses sont émises, notamment le rôle de l’hydrogénase et l’inhibition de l’action des sulfures.
6ème forum de biodétérioration des matériaux, La Rochelle, 23-24 octobre 2003
Titre : formation du biofilm marin : conséquences et perspectives
Année : 2003
Auteur(s) : Pineau S.
Abstract : Non disponible
Séminaire VALOMER, pôle technologique de Bidart (Biarritz). 3-4 octobre 2003
Titre : Electrochemical deposition of thin films of green rusts 1 and 2 on inert gold substrate
Année : 2003
Auteur(s) : Peulon S. Legrand L. Antony H. Chaussé A.
Abstract : Green rusts are layered Fe(II)–Fe(III) hydroxy-salts that play an important role in iron corrosion, soil chemistry, and environmental engineering. Successful electrochemical depositions of thin layers of green rusts incorporating anions such as carbonate or chloride (GRs1) or sulphate (GR2) on gold substrate are presented. As far as we know, it is the first time that such synthesis has been reported. The thin layers of green rusts were characterized by ex situ methods such as XRD, SEM, EDS and FTIR. This new way of synthesis allowed us to get green rust particles with sizes significantly larger than those obtained from the ways reported until now.
Electrochemistry Communications, Volume 5, Issue 3, March 2003, Pages 208-213
Titre : Synthèse électrochimique et applications de films minces de composés HDL et rouilles vertes
Année : 2003
Auteur(s) : Legrand L. Antony H. Peulon S. Chaussé A.
Abstract : Non disponible
GFECI
Titre : Transformations rédox et phénomènes de passivation d’hydroxydes doubles lamellaires de type rouilles vertes
Année : 2003
Auteur(s) : Legrand L. Antony H. Alhajji E. Peulon S. Chaussé A.
Abstract : Non disponible
GFECI
Titre : Behavior of thin layers of green rusts electrochemically deposited on iron and inert substrates
Année : 2003
Auteur(s) : Antony H. Legrand L. Chaussé A. Peulon S.
Abstract : The corrosion of iron is a well-know problem in
many domains like environment, nuclear, … Even if anticorrosion
solutions exist, it is practically impossible to
avoid the formation of oxidation products, especially in
the case of long-time contact of iron with corrosive
media.
The formation and structure of corrosion layers
are often very complex because a variety of corrosion
products can be formed, depending essentially on the
species present in the medium (soil, water, …).
Understanding the transformation pathways that occur
during the growth and evolution of a corrosion layer is a
hard challenge since it is difficult to clearly identify the
contributions of each corrosion product and the influence
of the iron substrate. Moreover, intermediate compounds
like green rusts [1] or amorphous ferric phases, are
particularly reactive and could induce local modifications
that can result from redox or adsorption reactions with
species present in the corrosive media .
That is why the studies on the behavior of an
oxidation product formed alone dependently and
independently of iron or another compound are very
interesting for many applications. In this case, it is
possible to get a better understanding of the
transformation or the stability of the compound and the
relationships with its local environment (oxidant or
reductive media), with the presence of inhibiting species
like silicate or phosphate ions, … Moreover the
interactivity of the product can be studied when it is in
contact with very redox-active species like chromate,
actinides, ….[2].
In this way, we studied the electrochemical
synthesis of thin layers of iron corrosion products on iron
and inert substrates (Au, Pt). Common corrosion products
(goethite, siderite, magnetite,…) could be formed
following this way of synthesis, as well as some
intermediate products such as green rusts (GR1 and GR2),
amorphous ferric phases, … In the case of green rusts and
as far as we know, it is the first time that the synthesis of
such thin layers has been reported on an inert substrate.
Studying the corrosion product as a thin layer on
a conducting substrate has many advantages compared to
a powder or a suspension : (i) the manipulation of samples
and their treatment (rinsing, drying) is generally easier,
(ii) electrochemical measurements can be directly
performed and coupled to in-situ techniques such as
electrochemical quartz microbalance (EQCM), micro-
Raman spectroscopy, (iii) ex-situ analyses (SEM, XPS,
IRRAS) are more easily operated even if the amount of
product is low.
This presentation will be particularly focussed on
the synthesis of thin layers of green rusts incorporating
anions such as carbonate or chloride (GRs1) or sulphate
(GR2) on iron, platinum or gold substrates, and on their
electrochemical behavior. These compounds belong to the
layered double hydroxides (LDH) group and have the
general formula FeII
(1-x)FeIII
x(OH)2].[x/nAn-,mH2O]. They
are intermediate products that may play an important role
during the building and evolution of corrosion layers. The
influence of parameters like concentration, pH
temperature or potential on the synthesis will be detailed,
as well as the characterization of the films by means of
usual techniques such as FTIR, XRD, SEM, EDS …
Figure 1 gives the SEM image of a carbonate green rust
layer, showing large well-crystallized particles. Figure 2
illustrates the kind of information that can be obtained
from a voltammetric study performed with a carbonate
green rust (GRc) layer in contact with a solution of
hydrogenocarbonate. The GRc-into-Fe(III)* solid-state
oxidation is revealed by the anodic peak ; two cathodic
peaks are observed on the reverse scan due to the
progressive transformation of Fe(III)* into Fe(III) [3].
Such electrochemical measurements give information on
the behavior of green rusts and on the transformation
pathways involving these species.
ECS
Titre : Influence de la protection cathodique, d’acier immergé en milieu marin, sur la vitesse de colonisation de la flore sulfurogène
Titre : Interactions entre la germination du dépôt calcomagnésien et la croissance de Desulfovibrio halophilus et Dethiosulfovibrio peptidovorans à la surface d’un acier carbone sous protection cathodique
