In this project, the partners from the scientific community and the economic sector propose to respond to the problems of the shellfish industry with the primary ambition to propose a new treatment process to protect early stage farms of marine molluscs (hollow oysters, flat oysters and clams), evaluate and compare it with existing disinfection and decontamination systems and feed water.
Studies from IFREMER have shown the presence of chemical contamination in the nearshore waters that feed the marine mollusc hatcheries (Ifremer ROCCH network, INSEV3i projects, SQUALE (SMIDAP funding) and LEAUPOLD (Loire Bretagne Water Agency funding). More specifically, the Marine Molluscs Experimental Platform of Bouin, France, works in the field of securing shellfish production and has been developing for 6 years projects to inactivate shellfish pathogens (DESIMER project) and the elimination of pesticides in seawater (ADAQUA project) with the objective of validating processes under real-life conditions (from larval to adult stages) .
AMU has studied the membrane filtration of seawater and the optimization of processes on industrial scales for different cases (i) depollution of contaminated seawater before its discharge to the sea in the case of bilge waters (SNCM, Société des Eaux de Marseille) or washing waters (CMACGM), (ii) disinfecting seawater (bacteria, virus, suspended solids) in the context of ballast water management (BIO-UV; CMACGM, Marseille FRET) and (iii) in the context of specific pollution (gametes) from hatcheries .
ENSCR, through the Chemistry and Process Engineering team, has a long history of working on the elimination of trace pollutants (ng.L-1 to µg.L-1) in complex environments (water, air). Adsorption processes are part of effective treatments to achieve this goal. During numerous research projects (Véolia, ANR PARME, Regional Projects, ANSES, etc.), efficient, selective, sustainable and economic processes were developed and benefited many partners (private companies, water unions, etc.). The CIP team also has extensive experience in modelling the removal of organic micropollutants in granular activated carbon filters and powdered activated carbon reactors. These technological developments are based on the understanding of fundamental physico-chemical phenomena (diffusion, interactions, reactions) and on the physical and chemical characterization of porous adsorbent materials. To do this, multiple analytical means are used (77K nitrogen adsorption, mercury porosimetry, thermogravimetry, etc.). Similarly, trace pollutants are detected and quantified by state-of-the-art analytical tools (chromatographs associated with mass spectrometry, on-line solid phase concentration, high-resolution mass spectrometry). Targeted or semi-targeted analyses make it possible to evaluate the effectiveness of adsorption processes under real conditions.
IMT Atlantique has already studied, via the ADAQUA projects in collaboration with Ifremer
the adsorption process used upstream of shellfish farms to prevent farms from any chemical contamination possibly present in seawater. The presence of chemical contaminants in French coastal oysters and mussels has been known for many years . It is due to the intensification of human activities in these areas which lead to discharges at sea from industry and wastewater treatment plants, for example, but also from leached soils during rainy periods. In this case, the polder of Bouin, France has an agricultural activity positioned directly around the oyster activities, and the occasional presence of certain phytosanitary products has been highlighted. The projects initially focused on simazine and metolachlor. Static and dynamic activated carbon adsorption tests were performed at the laboratory scale to obtain adsorption isotherms and breakthrough curves. The results obtained provided design elements and recommendations for the operation of the pilot unit implemented by the project partners. In a second phase, the project focused on glyphosate and AMPA, its by-product. These molecules require the development of specific analytical methods and are difficult to adsorb onto activated carbon . The prospects are to identify other adsorbents that can be better adapted to the retention of these molecules. Various studies indicate that zeolites or resins, some of which may be functionalized, could provide satisfactory responses to glyphosate retention [4, 5]. The particularity of the projects carried out by IMT Atlantique is to study these adsorbents under specific saltwater conditions. The particularity of the projects carried out by IMT Atlantique is to study these adsorbents under specific saltwater conditions.
The motivation of the four academic partners is therefore to make their complementary skills available to such a project. The industrial recognition of these partners is also in line with the objective of innovative technology transfer. The project thus implemented will allow the development of the following points:
- The performance of a system combining ultraviolet (UV) radiation and activated carbon adsorption will be evaluated in terms of elimination and fate of chemical contaminants and their potential by-products.
- On the other hand, with the same aims, a system combining ultrafiltration (UF) and adsorption will be developed and relevance will be demonstrated for the growth of juvenile oysters.
- The scientific knowledge acquired at the laboratory level will be confronted with controlled conditions on the experimental platforms of Ifremer at the semi-industrial scale, with initial milestones leading to the integration of couplings for the operation of larval farms for the two commercial hatcheries partners of the project, which will be the subject of the technology transfer. Indeed, the installation of water treatment pilot plants in the most optimal configuration will also be carried out at the two production sites. Essential information on the impact of UV disinfection systems, which are widespread in shellfish hatcheries, will also be acquired.