Atmospheric and marine CORrosions. Impact of chemical products - especially sulfur compounds - from Sargassum decomposition and role of microorganisms on corrosion of metAls. PhenomenologIcal and legal consideRations. – CORSAiR

The CORSAiR project is proposed by a multidisciplinary consortium of 9 partners with complementary scientific basis in molecular, biology, microbiology, corrosion, chemistry, applied physics in the fields of sensors and the design of electrochemical prototypes and in environmental law.
This complementarity was created in order to have the necessary tools to understand, characterize and model atmospheric and marine corrosion phenomena thus measuring their impact on metallic materials. The materials used mainly in electronic junctions in the atmosphere and those used for submerged structures.
In addition to the strong scientific composition of the consortium, the CORSAiR project has several advantages: the proximity of the field through two associations and the legislative approach that measures the impact on the population from a social angle.
This step is fundamental before being able to propose perennial solutions whose study of some are already taken into account in this project as well on the physicochemical aspect as on the legislative aspect.
In addition, the laboratories have a pool of complementary equipment that will also allow them to apprehend this project in the best conditions.

The CORSAiR project aims to assess the impact of Sargassum strandings on the degradation of metallic materials exposed to the aggressive and corrosive atmosphere but also to seawater laden with pollutants and bacterial communities participating in the sulfur cycle and responsible for biocorrosion, these two environments being consequences of the putrefaction of algae. After 6 months of initial work, the project identified several relevant sites for the exposure of metal samples and the study of corrosion on the Atlantic coast most affected by the Sargassum banks, but also a site inlands far from the littoral and another site on the Caribbean Coast much less impacted by the phenomenon. Several exhibition campaigns for metal samples of different types (zinc, copper, stainless steel, carbon steel) are planned with different durations of up to 2 years. Corrosion measurements via electrochemical and gravimetric methods have already started for the first campaigns and the first trends are emerging revealing differences depending on the terrain of exposure. In addition, in plus to an assessment of corrosivity, both physicochemical and biological solutions, as well as regulatory ones, must be provided in this project. Thus, the first extracts from a species of Sargassum showed significant inhibitory efficacy. Likewise, another species of marine algae, found in Caribbean seawaters, has shown interest in being studied as a biocidal and antifouling molecule. Finally, the exploration of the legal arsenal, carried out as exhaustively as possible, will make it possible to highlight the solutions that should be added to support the victims.

Concerning workpackage 1 (WP1, atmospheric corrosion), corrosion measurements on site and in the laboratory continue in order to qualify and quantify the degradation of materials linked to pollution of sargassum. the molecules responsible for the protection of metals in the plant extracts obtained will be identified and tested in field applications. Concerning WP2 (marine corrosion), the marine environment of the Sargassum will be characterized physically, chemically and biologically. The influence of the sulfur cycle bacteria communities on the degradation of materials will be evaluated. Formulations of biocidal and antifouling solutions obtained from the algae extracts studied will be applied to the materials in the field and in the laboratory. Regarding WP3 (legal approach), solutions will be proposed to address the problem of Sargassum after a survey of the population. Finally, concerning WP4 (Project management), a green class project for schoolchildren is currently being planned.

The project will allow the realization of several scientific articles on green corrosion inhibitors, green antifouling, corrosion related to the gaseous releases of Sargassum among others ...

The impacts associated with the stranding of Sargassum algae on the West Indian arc are numerous and diverse. Many sectors of the economy (tourism, fishing, degradation, ...), health (pneumology, ...), biodiversity, ... are affected.
The CORSAiR project, with its 9 partners in the West Indies and mainland France, aims to study the impact of these algae on the atmospheric and marine corrosion of metallic materials by also integrating a legal approach on these specific aspects. Indeed, many citizens, municipal authorities are worried about the premature degradation of many devices consisting of a metal envelope (refrigerator, ...) or plastic (computer, TV, ...) containing electronic cards. This generates significant costs and often plunges people into a state of desperation.
The objectives of the CORSAiR project are:
i) to quantify the kinetics of corrosion,
ii) to relate the phenomena of corrosion to the "presence" of Sargasso algae by identifying the mechanisms of degradation,
(iii) to find physicochemical solutions and to propose legal "arrangements",
iv) propose ways of valorization.
To carry out this project, the consortium will first rely on field feedback through 2 Martinique structures totally immersed and listening to the population and industry. This will make it possible to target the most scientifically sound coastal or inland areas, to benefit from a network of measures in place and to identify the demands coming from the citizens and the communities in order to answer them as well as possible. (legal approach).
The first area studied is that of atmospheric corrosion, the second area of marine corrosion and the third area concerns the legal approach to this problem.
The creation of a monitoring website for the "general public" project is also planned.