Réduction des micropolluants par les traitements complémentaires : fossé construit sur sol imperméable, filtres garnis de matériaux adsorbants (ARMISTIQ – Action B)
Le projet ARMISTIQ (« Amélioration de la réduction des micropolluants dans les stations de traitement des eaux usées domestiques ») a pour objectif d’évaluer et d’améliorer la connaissance et la maîtrise de technologies de traitements secondaire et complémentaire des substances prioritaires et émergentes présentes dans les eaux usées et les boues urbaines. L’action B porte sur deux procédés complémentaires susceptibles d’éliminer des micropolluants contenus dans les rejets de stations de traitement des eaux usées des communes rurales. Il s’agissait d’une part, d’étudier les rendements d’élimination de micropolluants par un fossé de 80 mètres de long construit sur sol imperméable (installation grandeur réelle), et d’autre part, d’étudier les rendements d’élimination de micropolluants par trois matériaux rapportés, adsorbants en grain (charbon actif, zéolite ou argile expansée), étudiés à l’échelle du laboratoire et à l’échelle de pilotes semi-industriels. Des protocoles d’analyses chimiques, fiables et robustes, ont été appliqués pour déterminer les concentrations de 16 métaux, 19 médicaments, 19 hydrocarbures aromatiques polycycliques (HAP), 6 alkylphénols (AKP) et 6 pesticides, choisis en raison de leurs différentes propriétés physicochimiques et leur persistance aux traitements secondaires. Le fossé de 80 mètres de long construit sur sol imperméable a montré une efficacité très limitée vis-à-vis de la réduction des micropolluants étudiés (rendements inférieurs à 30% pour les micropolluants réfractaires au traitement secondaire). Néanmoins, des rendements d’élimination compris entre 30 et 70% ont été mesurés pour quelques substances qui s’expliquent soit par adsorption sur l’argile du sol pour quelques métaux (cobalt, zinc, cadmium) soit par photodégradation pour quelques micropolluants organiques (paracétamol, ibuprofène). Des rendements d’élimination proches de 100% pendant plus de 330 jours ont été mesurés pour le filtre à charbon actif fonctionnant avec un temps de séjour hydraulique (HRT) de 1,5 heure. Seul le nonylphénol et quelques métaux ont eu des rendements moindres (50 à 80%). Un kilogramme de charbon actif a adsorbé les micropolluants contenus dans au moins 8 m3 d’eau usée traitée. Des rendements d’élimination supérieurs à 70% pour la moitié des substances pharmaceutiques et phytosanitaires étudiées ont été mesurés pour les filtres garnis de matériaux adsorbants en grain (argile expansée ou zéolite), alternatifs au charbon actif, avec un HRT de 24 heures. Les rendements d’élimination obtenus pour les autres substances sont bien moindres qu’avec le charbon actif, mais restent supérieurs à ceux mesurés avec des filtres à graviers ou à apatite. Un kilogramme d’argile ou de zéolite a adsorbé les micropolluants contenus dans environ 0,3 m3 d’eau usée traitée, et les filtres ont saturé au bout de quelques mois. Avec un HRT plus court (4 heures), la saturation est intervenue au bout d’une vingtaine de jours seulement. Les perspectives de ce travail concernent l’évaluation d’autres procédés complémentaires, comprenant une succession de bassins de faibles profondeurs d’eau libre, ainsi que des procédés construits sur sol perméable.
(pp. 64, 30/08/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Bioaccumulation of perfluoroalkyl compounds in midge (Chironomus riparius) larvae exposed to sediment
Midge larvae (Chironomus riparius) were exposed to sediments from a deposition sampled at a site along the Rhône River (France) downstream of an industrial site releasing various perfluorinated chemicals. This sediment is characterized by high concentrations of perfluoroundecanoic acid (PFUnA) and perfluorotridecanoic acid (PFTrDA) and a low perfluorooctane sulfonate (PFOS) concentration. Concentrations of 23 perfluoroalkyl compounds, including C4eC14 carboxylate acids, C4eC10 sulfonates, and seven precursors, were analyzed in overlying and pore water, sediment, and larvae. Midge larvae accumulated carboxylate acids (C11eC14), PFOS, and two precursors (perfluorooctane sulfonamide: FOSA and 6:2 fluorotelomer sulfonic acid, 6:2 FTSA). These substances accumulated mainly during the fourth instar larvae exponential growth phase. Accumulation of 6:2 FTSA, PFUnA, and PFOS occured via trophic and tegumentary routes. Other compounds mainly accumulated from food. Kinetics followed a partition model, from which uptake and elimination constants were derived.
(Environmental Pollution. vol. 189, n° 0269-7491, pp. p. 27 - p. 34, 30/08/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, ECCC
Fluid Seepage in Relation to Seabed Deformation on the Central Nile Deep-Sea Fan, Part 1: Evidence from Sidescan Sonar Data,
The central Nile Deep-Sea Fan contains a broad area of seabed destabilisation in association with fluid seepage: slope-parallel sediment undulations are associated with multibeam high-backscatter patches (HBPs) related to authigenic carbonates. During the 2011 APINIL campaign, a deep-towed sidescan and profiling system (SAR) was used to acquire high-resolution data along three transects across water depths of 1,700-2,650 m. Three seabed domains are distinguished, all developed within stratified sediments overlying mass-transport deposits (MTDs). Upslope of the undulations (<1,950 m), sidescan HBPs record focused fluid seepage via seabed cracks. In the western area of undulations, sidescan HBPs are distinct from intermediate-backscatter patches (IBPs) that extend up to 850 m parallel to the undulations, mainly along their downslope flanks; some contain sub-circular HBPs up to 300 m wide, three associated with smaller (<10 m) hydroacoustic gas flares. Focused fluid seeps are inferred to have shifted over time to form elongate carbonate pavements, preferentially along the footwalls of faults beneath the undulations that provide pathways for fluid flow. In contrast, in the eastern area of undulations, sidescan imagery reveal only slope-transverse furrows formed by turbulent flows, interpreted to indicate that fossil carbonates sampled during submersible operations have been exhumed by erosion.
(Advances in Natural and Technological Hazards Research. vol. 37, pp. 129-139, 30/08/2026)
GEOAZUR 7329, INSU - CNRS, UniCA, CNRS, IRD [Occitanie], IRD, UniCA, OGS, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Single and mixture effects of pesticides and a degradation product on fluvial biofilms
The Morcille River located in the Beaujolais vineyard area (Eastern France) is subjected to strong vine-growing pressure leading to the contamination by a range of herbicides and fungicides of the surrounding freshwater environment. Particularly high concentrations of norflurazon, desmethyl norflurazon and tebuconazole were recorded in spring 2010 at the downstream site of the river. Despite their occurrence in rivers, scarce toxicity data are available for these products, in particular in the case of desmethyl norflurazon (main norflurazon degradation product). Furthermore, the toxicity data are generally available only for single compounds and are issued from single species toxicity tests, leading to a lack of ecological relevance. Consequently, this study was undertaken to evaluate the toxic effects of norflurazon, desmethyl norflurazon and tebuconazole singly and in a ternary mixture on fluvial biofilm. Toxicity tests were performed in microplates for 48 h. Photosynthetic endpointsweremeasured using pulse amplitude-modulated fluorometry; diatom densities and taxonomic composition were determined. After 48 h of exposure, significant effects on optimal quantumyield (Fv/Fm) for desmethyl norflurazon and mixturewere observed.
(Environmental Monitoring and Assessment. vol. 186, n° 0167-6369, pp. 3931-3939, 30/08/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Removal Of Non-Conventional Contaminants From Wastewaters
Removal Of Non-Conventional Contaminants From Wastewaters
(pp. 20, 30/08/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
PCB contamination in fish community from the Gironde Estuary (France): Blast from the past
The contamination of the Gironde Estuary, southwest of France, by polychlorinated biphenyls (PCBs) was assessed using six fish of high ecological and economic importance as bioindicator species. The concentrations of 21 PCB congeners and total fat contents were determined in the muscle and liver of eels (Anguilla anguilla), seabass (Dicentrarchus labrax), flounders (Platichthys flesus), meagres (Argyrosomus regius), mullets (Liza ramada), and soles (Solea vulgaris). In addition, information regarding the trophic ecology of the studied fish was obtained through the analysis of carbon and nitrogen stable isotopes (i.e., d13C and d15N) in muscle. Results revealed high PCB concentrations in fish compared to monitored European estuaries. The muscle of eels was by far the most contaminated fish flesh (R7PCBs = 1000 ± 440 ng g1 on a dry weight basis), while the higher PCB concentrations in liver were measured in flounder (R7PCBs = 2040 ± 1160 ng g1 d.w.). A quantile regression approach allowed to investigate the fate of PCBs in the Gironde estuarine fish assemblage, and revealed a general process of trophic magnification. Finally, most of the analysed fish presented PCB concentrations in muscle meat above the current European maximum limits for sea products, while the derived 'Toxic Equivalent Quantity' (TEQ) revealed human health concerns only for high-fat fish consumption.
(Chemosphere. vol. 98, n° 0045-6535, pp. 66-72, 30/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR EME, IRD, IFREMER, UM, UR EABX, IRSTEA
Removal of xenobiotics from effluent discharge by adsorption on zeolite and expanded clay: an alternative to activated carbon?
Xenobiotics such as pesticides and pharmaceuticals are an increasingly large problem in aquatic environments. A fixed-bed adsorption filter, used as tertiary stage of sewage treatment, could be a solution to decrease xenobiotics concentrations in wastewater treatment plants (WWTPs) effluent. The adsorption efficiency of two mineral adsorbent materials (expanded clay (EC) and zeolite (ZE)), both seen as a possible alternative to activated carbon (AC), was evaluated in batch tests. Experiments involving secondary treated domestic wastewater spiked with a cocktail of ten xenobiotics (eight pharmaceuticals and two pesticides) known to be poorly eliminated in conventional biological process were carried out. Removal efficiencies and partitions coefficientswere calculated for two levels of initial xenobiotic concentration, i.e, concentrations lower to 10 microg/L and concentrations ranged from 100 to 1,000 microg/L. While AC was the most efficient adsorbent material, both alternative adsorbent materials showed good adsorption efficiencies for all ten xenobiotics (from 50 to 100 % depending on the xenobiotic/adsorbent material pair). For all the targeted xenobiotics, at lower concentrations, EC presented the best adsorption potential with higher partition coefficients, confirming the results in terms of removal efficiencies. Nevertheless, Zeolite presents virtually the same adsorption potential for both high and low xenobiotics concentrations to be treated. According to this first batch investigation, ZE and EC could be used as alternative absorbent materials to AC in WWTP.
(Environmental Science and Pollution Research. vol. 21, n° 0944-1344, pp. 5660-5668, 30/08/2026)
UR MALY, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR Qualisud, Cirad, UM1, UM2, Montpellier SupAgro, AU, UR, UM, Montpellier SupAgro
Contributions and potential impacts of seven priority substances (As, Cd, Cu, Cr, Ni, Pb, and Zn) to a major European Estuary (Gironde Estuary, France) from urban wastewater
Urban wastewater metal inputs into coastal systems are of increasing interest to both scientists and managers facing restrictive environmental protection policies, population increase and changing metal applications. However, their impact and contribution to metal loads in estuarine and coastal environments is widely unknown due to the lack of (i) monitoring in both artificial and natural aquatic systems and (ii) an understanding of control parameters, such as spatial and temporal variations in hydrological conditions. We investigated the daily concentrations, fluxes and dynamics of seven EU priority contaminants (potentially toxic metals Cd, Cu, Cr, Ni, Pb, Zn and the metalloid As) transported by the Garonne River (La Réole site; watershed area ~ 57,000 km2) to those released into the freshwater reaches of the Gironde Estuary (Garonne Branch) by two main wastewater treatment plants (WWTPs) of Bordeaux under low river discharge and contrasting rainfall situations. During short intense summer rainstorms, wastewater flow into the WWTPs increased by up to 150% and 60%, respectively, resulting in an increase of 70% (As) to 200% (Pb) for fluxes entering the treatment plants. Overall resulting WWTP particulate and dissolved effluent concentrations were up to 2 (Cr), 3 (Pb, Cu and Ni) and 5 (Cd and Zn) times higher than measured upstream in the Garonne River, respectively. During low-discharge, maximum outlet fluxes at the WWTPs were similar to respective watershed-derived fluxes in the Garonne River. During rain events, Pb in all fractions, total and dissolved Cu and total and particulate Zn fluxes entering the fluvial estuary were close to the respective minimum flux values at the La Réole site. Furthermore, during rain episodes, particulate Cu and dissolved Zn fluxes from the WWTPs to the fluvial estuary were greater than those transported by the Garonne River at the La Réole site. Mixing of treated wastewater with highly turbid estuarine freshwater most likely results in a re-equilibration between the dissolved and particulate phases, although biogeochemical processes in downstream estuarine turbidity and salinity gradients may partly reverse contaminant adsorption on estuarine particles. Accordingly, urban wastewater contaminant release clearly impacts estuarine water quality before being expulsed to the Bay of Biscay.
(Marine Chemistry. vol. 167, n° 0304-4203, pp. 123-134, 30/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Persistent Organic Pollutants in a marine bivalve on the Marennes-Oléron Bay and the Gironde Estuary (French Atlantic coast) -Part 2: Potential biological effects
Contaminant effects on defence responses of ecologically and economically important organisms, such as the Pacific oyster Crassostrea gigas, are likely to influence their ability to resist infectious diseases, particularly at the young stages. The aim of this study was to explore the potential relationships between organic contaminants accumulated in the soft tissues of juvenile oysters, defence responses and physiological condition. Oysters were transplanted during summer and winter periods in different sites in the Marennes-Oléron Bay, the first area of oyster production in France, and in the Gironde Estuary, the biggest estuary in Occidental Europe. Among the battery of biochemical and physiological biomarkers applied in the present work (superoxide dismutase -SOD-, catalase, glutathione peroxidase -GPx-, malondyaldehyde -MDA-, catecholase, laccase and lysozyme in gills, digestive gland, mantle and haemolymph, glycogen, proteins and lipids in the digestive gland and the condition index at the whole organism level), MDA and lysozyme in the digestive gland and SOD, GPx and laccase in plasma contibuted to significantly discriminate sites in which oysters bioaccumulated different levels of heavy polycyclic aromatic hydrocarbons (HPAHs), polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs) and lindane. These results strengthen the hypothesis that it is possible to differentiate sites depending on their contamination levels and biological effects by carrying out studies with transplanted juvenile oysters. In addition, correlations between antioxidant and immune defence responses and PAH and DDT body burdens in the first area of oyster production in France, the Marennes-Oléron Bay, and where massive oyster mortalities have been reported, suggest that the presence of organic chemical contaminants in the Marennes-Oléron Bay may influence defence responses in juveniles of C. gigas, and, therefore, could influence their ability to resist infectious diseases.
(Science of the Total Environment. vol. 514, n° 0048-9697, pp. 511-522, 30/08/2026)
PUJ, LIENSs, INSU - CNRS, ULR, CNRS, UB, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Influence of sediment composition on PAH toxicity using zebrafish (Danio rerio) and Japanese medaka (Oryzias latipes) embryo-larval assays
Due to hydrophobic and persistent properties, polycyclic aromatic hydrocarbons (PAHs) have a high capacity to accumulate in sediment. Sediment quality criteria, for the assessment of habitat quality and risk for aquatic life, include understanding the fate and effects of PAHs. In the context of European regulation (REACH and Water Framework Directive), the first objective was to assess the influence of sediment composition on the toxicity of two model PAHs, benzo[a]pyrene and fluoranthene using 10 day-zebrafish embryo-larval assay. This procedure was undertaken with an artificial sediment in order to limit natural sediment variability. A suitable sediment composition might be then validated for zebrafish and proposed in a new OECD guideline for chemicals testing. Second, a comparative study of toxicity responses from this exposure protocol was then performed using another OECD species, the Japanese medaka. The potential toxicity of both PAHs was assessed through lethal (e.g. survival, hatching success) and sublethal endpoints (e.g. abnormalities, PMR and EROD) measured at different developmental stages, adapted to the embryonic development time of both species. Regarding effects observed for both species, a suitable artificial sediment composition for PAH toxicity testing was set at 92.5 % dw silica of 0.2-0.5 mm grain size, 5 % dw kaolin clay without organic matter for zebrafish and 2.5 % dw blond peat in more only for Japanese medaka. PAH bioavailability and toxicity were highly dependent on the fraction of organic matter in sediment and of the Kow coefficients of the tested compounds. The biological responses observed were also dependent of the species under consideration. Japanese medaka embryos appeared more robust than zebrafish embryos for understanding the toxicity of PAHs due to the longer exposure duration and it lower sensitivity of sediment physical properties.
(Environmental Science and Pollution Research. vol. 21, n° 0944-1344, pp. 13703 - 13719, 30/08/2026)
LIENSs, INSU - CNRS, ULR, CNRS, IFREMER, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LPGP, INRA, Biosit : Biologie - Santé - Innovation Technologique