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The Akkar plain is the second largest agricultural area in Lebanon. This region produces huge amount of regular crops such as maize, fruits, and vegetables. In order to protect the crops, farmers use large quantities of many pesticides (including authorized and prohibited molecules) without respecting the recommended doses. In this work, we wanted to study the evolution of OCP and OPP residues at 3-year intervals in water wells in the Akkar region. Twenty OCPs and 8 OPPs were monitored in eight wells in different villages in the plain and mountains of Akkar. Solid phase extraction (SPE) method was used for pesticide extraction, followed by gas chromatography-mass spectrometry (GC-MS) analysis. The results revealed an increasing concentration of OCPs and OPPs in groundwater over the last 3 years (between 2017 and 2019-2020). This increase in contamination is due to the uncontrolled and still unregulated (by the authorities) use of pesticides, and also to the introduction of new crops. The concentrations found in groundwater confirm that some banned pesticides are still widely used. The calculation of the theoretical pesticide intake suggests that pesticide concentrations in Akkar represent a greater health risk for the population consuming well water during the rainy season.

International audience; Active functional groups in biofilms determine the adsorption and desorption of contaminants and nutrients. Epilithic biofilms were characterized in order to understand the association between the chemistry alteration patterns and the surrounding anthropic activities of the Guaporé River watershed. The instrumental analyses included pyrolysis coupled to gas chromatography and mass spectroscopy, spectroscopy in the IR region with attenuated total reflectance and two-dimensional nuclear magnetic resonance. Spectrometric techniques demonstrated that epilithic biofilms are mainly composed of polysaccharides, nitrogencontaining compounds, lipids, and aromatic and phenolic structures, which have functional groups characteristic of alcohols, esters, ethers and amides. The polysaccharide levels reflect well the environmental pressures. The chemical composition of epilithic biofilms can be an effective tool for environmental assessment in watercourses, since the different anthropic actions developed in watersheds, mainly agriculture and urban areas, can modify the organic fraction of biofilms.

International audience; A new green method for trace level quantification of four herbicides, glyphosate (GLYP), glufosinate (GLUF), and their main metabolites, aminomethylphosphonic acid (AMPA) and 3-(methyl-phosphinico)propionic acid (MPPA), was developed. The purification step without any derivatization was conducted by solid-phase extraction using Chelex-100 resin in the Fe (III) form, followed by elution with 5% NH4OH. The four analytes were quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry. The developed extraction method was validated on five fresh and sea water matrices with mean recoveries ranging from 80.1% to 109.4% (relative standard deviation < 20%). The extraction conditions were evaluated and certified for the high applicability of the extraction method too. The limits of detection (ng/L) in the five water matrices were in ranges 0.70 - 4.0, 2.4 - 3.9, 1.8 - 4.7, and 1.6 - 4.0 for GLYP, AMPA, GLUF, and MPPA, respectively. The method was successfully applied to detect the four compounds in surface waters sampled along the Red River Delta region in July 2019. The highest concentrations were detected at 565, 1,330, 234, and 871 ng/L for GLYP, AMPA, GLUF, and MPPA, respectively. These results showed the potential capacity of this new method for convenient monitoring of herbicides and their metabolites in the diverse natural water system.

The no-tillage system combining winter cover crops and crop rotation may increase the efficiency use of soil P and phosphate fertilizer. The objective of this study was to evaluate the effect of three decades of different soil management systems and winter cover crops on the fractions of P in a clayey Oxisol of Parana State, Brazil. The bi-factorial experiment with three replicates was established in 1986. The main plots consisted of seven winter cover crops. In the subplots, two tillage systems were used: no-tillage and conventional tillage. The soil was sampled in the 0–10 cm soil layer in each plot in the post-harvest of the corn (March 2015), the flowering of the winter cover crops (September 2015) and at soybean flowering (February 2016). Samples from a native forest adjacent to the experimental area were also taken for comparison. The different pools of P were evaluated. Results indicated that after 30 years of no-till with phosphate fertilizers addition, the amount of P organic pools and type of P organic compound were very similar to those observed in the natural biome. The no-tillage guaranteed higher inorganic and organic P, both rapid and moderately available, in comparison to the conventional tillage system. However, in the conventional tillage (40 years − 80 plows + 160 harrows), despite the addition of 3 Mg ha−1 of P2O5, the available and moderately labile P content in soil surface were very similar to soil under natural forest. In the natural biome, the amount of P stored in soil microbial biomass was stable in the time showing a homeostatic equilibrium. Nevertheless, in cultivated soil and fertilized with inorganic phosphate, there was a synchronism between plant demand and storage in soil microbial biomass. Except for P stored in soil microbial biomass, the other P pools, regardless its nature (organic or inorganic) or degree of bioavailability, had despicable or absent effect of winter cover plants, compared to winter fallow.

With questions emerging on the presence and risks associated with metabolites and transformation products (TPs) of organic contaminants in the aquatic environment, progress has been made in terms of monitoring and regulation of pesticide metabolites. However, less interest is shown for pharmaceutical residues, although their pseudo-persistence and adverse effects on non-target organisms are proven. This study provides original knowledge about the contamination of ten sites located along three French rivers (water, sediments, biofilms, clams) by pharmaceutical metabolites and TPs, as well as a preliminary environmental risk assessment. Studied compounds included carbamazepine with five metabolites and TPs, and diclofenac with three metabolites and TPs. Results show that metabolites and TPs are present in all studied compartments, with mean concentrations up to 0.52 µg L-1 in water, 229 ng g-1 in sediments, 2153 ng g-1 in biofilms, and 1149 ng g-1 in clams. QSAR estimations (OECD toolbox) were involved to predict the studied compounds ecotoxicities. QSAR models showed that diclofenac and its metabolites and TPs could be more toxic than carbamazepine and its metabolites and TPs to three aquatic species representing green algae, invertebrates, and fish. However, real ecotoxicological effects are still to be determined. The environmental risk assessment showed that hydroxydiclofenac, 2-[(2-chlorophenyl)-amino]-benzaldehyde and dibenzazepine could present a greater risk than other studied compounds for aquatic organisms. In addition, the risk associated with a mixture of diclofenac and its related metabolites and TPs has been found to be greater than that of the compounds considered individually.

The Bienne river (Jura Mountain, France) drains a basin of medium altitude mountains characterized by extensive cattle breeding (mostly dairy cows). A monitoring of the contamination by veterinary pharmaceuticals was performed using passive sampling devices - POCIS (Polar Organic Chemical Integrative Samplers), between September 2019 and January 2020. Four hydrological conditions were analysed: a sever low-flow periods, two flood events and a winter situation close to the mean interannual flow. Each time, POCIS were exposed over 2 weeks at 2 stations located in the upper and downstream reaches of the river. 19 pharmaceuticals were selected from information given by local veterinarians and analysed by LC MS-MS: endo and ectoparasites treatments; antibiotics and non-steroidal anti-inflammatory drugs. The monitoring shows that most of these chemicals (12 substances) are quantified in all POCIS samples and the others show relatively high occurrences, between 25 and 88%. Average concentrations in water (calculated with the sampling rate i.e. considering the time of exposition of POCIS samplers in the river) are remarkably close between the 2 monitoring stations. Concentrations are high all over the studied period and reach a maximum during flood events. Thus, hazardous effects are expected on freshwater organisms, especially for macrocyclic lactones and pyrethroids and organophosphates pesticides. The antibiotics concentrations ranges can also disturb microbial communities existing in the river. Such results highlight an important impregnation by these pharmaceuticals at the catchment scale, involving diffuse sources as grasslands receiving contaminated cow dungs and manures. Veterinary compounds are strongly remobilized during rain episodes by run off and infiltration in soils. In the hydrogeological context of the Bienne basin, karstic flows emphasize the connectivity between grasslands and the river. Therefore, an important part of the contaminated leaching waters can rapidly reach the river via the soil drains and surface / subsurface flows. Rather than another part goes through less porosity pathways and delivers pollutants over a longer period. Wastewater discharges and sludges from rural and urban treatment plants can also contribute to this pollution for pharmaceuticals also used in human medications.

International audience; Understanding the transformations of highly reduced enstatite chondrites (EC) in terrestrial environments, even on very short timescales, is important to make the best use of the cosmochemical and mineralogical information carried by these extraterrestrial rocks. Analogs of EC meteorites were synthesized at high pressure and high temperature. Then, their aqueous alterations, either abiotic or in the presence of the bacteria Acidithiobacillus ferrooxidans or Acidithiobacillus thiooxidans, were studied under air, at pH ~2, 20 °C, and atmospheric pressure. They stayed in shaken batch reactors for 15 days. Reference experiments were carried out separately by altering only one mineral phase among those composing the synthetic EC (i.e., sulfides: troilite or Mg‐Ca‐rich sulfides, enstatite, and Fe70Si30). Composition of the alteration aqueous media and microstructures of the weathered solids were monitored by inductively coupled plasma atomic emission spectroscopy and by scanning electron microscopy, respectively. Alteration sequence of the different mineral components of the synthetic EC was found to occur in the following order: magnesium‐calcium sulfides > troilite > iron‐silicon metallic phase > enstatite regardless of the presence or absence of the microorganisms. Such small biological effects might be due to the fact that the alteration conditions are far from biologically optimal, which is likely the case in most natural environments. The exposed surfaces of an EC meteorite falling on Earth in a wet and acidic environment could lose within a few hours their Ca‐ and Mg‐rich sulfides (oldhamite and niningerite). Then, in

International audience; The fate of pharmaceuticals during the treatment of effluents is of major concern since they are not completely degraded and because of their persistence and mobility in environment. Indeed, even at low concentrations they represent a risk to aquatic life and human health. In this work, fourteen pharmaceuticals were monitored in a constructed wetland wastewater treatment plants (WWTP) assessed in both influent and effluent samples. The basic water quality parameters were evaluated and the removal efficiency of pharmaceutical, potential for bioaccumulation and the impact of WWTP were assessed using Polar Organic Chemical Integrative Sampler (POCIS) and biofilms. The pharmaceuticals compounds were quantified by High Performance Liquid chromatography coupled to mass spectrometry. The sampling campaign was carried out during winter (July/2018) and summer (January/2019). The WWTP performed well regarding the removal of TSS, COD 5 ans BOD; succeeded to eliminate a significant part of the organic and inorganic pollution present in domestic wastewater but has low efficiency regarding the removal of pharmaceutical compounds. Biofilms were shown to interact with pharmaceuticals and were reported to play a role in their capture from water. The antibiotics were reported to display a high risk for aquatic organisms.

The fate of pharmaceuticals during the treatment of effluents is of major concern since they are not completely degraded and because of their persistence and mobility in environment. Indeed, even at low concentrations, they represent a risk to aquatic life and human health. In this work, fourteen pharmaceuticals were monitored in a constructed wetland wastewater treatment plants (WWTP) assessed in both influent and effluent samples. The basic water quality parameters were evaluated, and the removal efficiency of pharmaceutical, potential for bioaccumulation, and the impact of WWTP were assessed using Polar Organic Chemical Integrative Sampler (POCIS) and biofilms. The pharmaceutical compounds were quantified by High Performance Liquid chromatography coupled to mass spectrometry. The sampling campaign was carried out during winter (July/2018) and summer (January/2019). The WWTP performed well regarding the removal of TSS, COD, and BOD

International audience; Since the early 20's antibiotics have been massively produced and consumed for the benefit of bothhuman and animal health. Nevertheless, antibiotics have also reached the aquatic environmentthrough diffuse sources (e.g. veterinary treatment, contaminated manure application...) and throughwastewater. Consequently, antibiotics concentrations between the ng/L and μg/L range are regularlydetected in surface water and those molecules have also been found in sediments and aquatic biota.The ubiquitous presence of antibiotics exerts a selective pressure on microbial communities leading tothe acquisition and dissemination of antibioresistance in the environment. While both antibiotics andantibioresistance have been found in different aquatic compartments, more investigation is requiredto better understand their distribution and to identify hot spots of accumulation.In this context, we investigated the repartition of antibiotics and antibioresistance in different aquaticcompartments on 4 stations belonging to regional observatories and presenting contrasting levels ofpharmaceuticals: 2 on the Arve river belonging to Sipibel observatory and 2 on Lake Geneva belongingto the Observatory on Lakes. On the Arve river, the 2 stations were located up- and down- stream thedischarge place of a wastewater treatment plant (WWTP) collecting both urban and hospitalwastewaters. On Lake Geneva, one station was located in a relatively pristine area while the secondwas close to the discharge of an urban WWTP. To better identify a potential temporal dynamic ofantibiotics and antibioresistances over seasons, 6 samplings were conducted during 1.5 year. On eachsampling campaign, the following parameters were determined: (i) antibiotics levels in water,sediments and periphyton; (ii) antibioresistance in periphyton and sediments using various techniques:detection of resistance genes, integrons quantification, detection of tolerance acquisition via a PICT(Pollution Induced Community Tolerance) approach; (iii) antibiotics biodegradation potential ofmicrobial community from sediments (by radiorespirometric measurement); (iv) diversity of bacteriaand diatoms in periphyton and sediments; (v) physico-chemical parameters and (vi) metalliccontamination in sediments.While microbial resistance to antibiotics is commonly assessed by quantifying resistance genes orisolating antibiotic resistant bacteria, antibiotic resistance can also be estimated by measuring theacquisition of antibiotics tolerance at community level, following a PICT approach. In our study,periphytic microbial communities from the Arve river were found to have a higher tolerance to thetested antibiotics (ciprofloxacin, ofloxacin, sulfamethazine and erythromycin) than communities fromLake Geneva, in agreement with the expected levels of contamination. In addition, in some cases, ahigher tolerance was also found at stations close to WWTP effluents than in upstream/protectedstations. For example, periphytic microbial communities collected downstream the WWTP on the Arveriver were generally found to have a higher tolerance to ciprofloxacin than the upstream communities.Comparing whole community tolerance to other classical indicators of antibioresistance and toantibiotics levels in the aquatic ecosystems allows us to better understand the interconnectionbetween pharmaceutical exposure, in situ tolerance and genetic potential for antibioresistance.

Brazil is one of the largest consumers of pesticides in the world. The high rainfall rate and inadequate soil use and management promote the transfer of these compounds to the aquatic system. The aim of this study was to identify and quantify pesticides present in epilithic biofilms in order to evaluate the effectiveness of this matrix as a bioindicator able to discriminate areas and periods with different inputs of pesticides. Among the 25 pesticides analyzed in the biofilms, 20 compounds were detected. The epilithic biofilms picked up pesticides independent of their polarities, even in the period of lower use. The frequency and median concentration of five herbicides (2,4-D, atrazine, desethyl-atrazine, simazine, nicosulfuron), three fungicides (carbendazim, epoxiconazole, tebuconazole), and one insecticide (imidacloprid) were highest in biofilms sampled in summer crops during the growing period. Biofilms collected in the upper region of the catchment, where genetically modified soybean and corn cultivated in a no-tillage system prevail, the highest frequency and median concentration of three herbicides (2,4-D, thifensulfuron, isoproturon), four fungicides (carbendazim, epoxiconazole, tebuconazole, metconazole), and one insecticide (imidacloprid) were observed. Despite the excessive amounts of pesticides used in the catchment, the median values of all pesticides in the epilithic biofilm were considered low. The lower diversity and concentration of pesticides observed in the autumn/winter season is representative of lower use of pesticides, barriers to pesticide transfer from soil to water, and the biofilm's resilience capacity to decompose pesticides.

International audience

The UV/chlorine process as a potential tertiary municipal wastewater treatment alternative for removing refractory PPCPs has been widely investigated. However, the role of effluent organic matter (EfOM) on the radical chemistry and toxicity alteration is unclear. The elimination of two model PPCPs, primidone (PRM) and caffeine (CAF), by the co-exposure of UV and free chlorine was investigated to elucidate the impact of EfOM. Experimental results indicated that both •OH and reactive chlorine species (RCS) were importantly involved in the decay of PRM at acidic condition, while ClO• played dominant role at alkaline pH. The decay of CAF was dominated by ClO• under all conditions. Chlorine dose, initial contaminant concentration, solution pH, and water matrix affect the process efficiency at varying degree resulting from their specific effect on the radical speciation in the system. Presence of EfOM isolate remarkably inhibited the decay of PRM and CAF by preferentially scavenging RCS and particularly ClO•. Good correlations (linear for PRM and exponential for CAF) between UV absorbance at 254 nm and the observed pseudo first-order rate constants (k'obs) for all EfOM solutions were obtained, demonstrating the importance of aromatic moieties in inhibiting the degradation of targeted contaminants by UV/chlorine process. Degradation of PRM/CAF in reconstituted effluent spiked with the major effluent constituents (i.e., EfOM isolates, Cl-, HCO3-, and NO3-) was comparable to the results obtained with the real WWTP effluent and fit well to the correlation between k'obs and UV absorbance at 254 nm, suggesting that EfOM isolates can be used to determine the efficiency of UV/chlorine process in real effluent. EfOM serves as the main precursor of adsorbable organic chlorine in the UV/chlorine treatment. Bioassays indicated that chlorine-containing compounds could induce oxidative stress, mitochondrial dysfunction, and increase the cell DNA damage. Among evaluated treatment conditions, the nature of EfOM, hydrophobic versus transphilic fraction, is likely the predominant factor affecting the cytotoxicity. Meanwhile the UV/chlorine treatment can significantly reduce the cytotoxicity of EfOM isolates. However, adding high level of selected contaminants (e.g., PRM and CAF) can inhibit this phenomenon due to the competition with reactive radicals.

The widespread adoption of the sediment fingerprinting approach to guide catchment management has been limited by the cost and the difficulty to prepare and process samples for geochemical and radionuclide analyses. Spectral properties have recently been shown to provide a rapid and cost-efficient alternative for this purpose. The current research objective was (i) to quantify the sediment source contributions in a 1.19-km2 rural catchment of Southern Brazil by using mid-infrared (MIR) spectroscopy, and (ii) to compare these results with those obtained with geochemical approach and near-infrared (NIR) and ultraviolet-visible (UV-VIS) spectroscopy methods. The sediment sources to discriminate were cropland surface (n = 20), unpaved roads (n = 10) and stream channel banks (n = 10). Twenty-nine suspended sediment samples were collected at the catchment outlet during nine significant flood events. The sources could be distinguished by MIR spectroscopy. Cropland and channel bank sources mainly differed in their clay mineral contents, but their similar organic matter content complicated the MIR-model predictions. Unpaved road contributions were discriminated from the other sources by their lower organic carbon content. When the results of the current research based on MIR spectroscopy are compared to those obtained using other sediment fingerprinting approaches, based on geochemistry and NIR and UV-VIS spectroscopy, an overestimation of channel banks contribution and an underestimation of cropland and unpaved road contributions is found. These results suggest that MIR spectroscopy can provide a useful tool that is non-destructive, rapid and cheap for tracing sediment sources in rural catchments and for guiding the implementation of soil and water conservation measures.

The total cultivated area in Brazil reached to 62 million ha in 2018, with the predominance of genetically modified soybean and corn (36 and 17 million ha, respectively) in no-tillage systems. In 2018, 5.3 × 105 Mg of active ingredient of pesticides was applied in cropfields, representing about 7.3 L of commercial product by habitant. However, the monitoring of water courses contamination by pesticides remains scarce and is based on traditional grab sampling systems. In this study, we used the grab (water) and passive sampling (Polar Organic Chemical Integrative Sampler—POCIS) to monitor pesticide contamination in the river network of a representative agricultural catchment of southern Brazil. We selected 18 sampling sites located in tributaries and in the main course of the Guapore River, in Rio Grande do Sul State, with different land use predominance including forest, urban, and agricultural areas. Altogether, 79 and 23 pesticides were, respectively, analyzed in water and POCIS samples. The water of Guapore River and its tributaries were highly contaminated by many pesticides, especially by four herbicides (2,4-D, atrazine, deethyl-atrazine, and simazine), three fungicides (carbendazim, tebuconazole, and epoxiconazole), and one insecticide (imidacloprid). The amount, type, and concentration of pesticides detected were completely different depending on the sampling technic used. POCIS was effective to discriminate the contamination according to the main land use of each sampling site. The monitored areas with the predominance of soybean cultivation under no-tillage tended to have higher concentrations of fungicide, while in the more diversified region, the herbicides showed higher values. The presence of five herbicides used in corn and grassland forage production was correlated with areas of integrated crop-livestock systems, in contrast to higher contamination by 2,4-D in areas of intensive production of soybean and winter cereals.

International audience; Freshwater ecosystems are continuously affected by anthropogenic pressure. One of the main sources of contamination comes from wastewater treatment plant (WWTP) effluents that contain wide range of micro- and macropollutants. Chemical composition, toxicity levels and impact of treated effluents (TEs) on the recipient aquatic ecosystems may strongly differ depending on the wastewater origin. Compared to urban TEs, hospital ones may contain more active pharmaceutical substances. Benthic diatoms are relevant ecological indicators because of their high species and ecological diversity and rapid response to human pressure. They are routinely used for water quality monitoring. However, there is a knowledge gap on diatom communities' development and behavior in treated wastewater in relation to prevailing micro- and macropollutants. In this study, we aim to (1) investigate the response of diatom communities to urban and hospital TEs, and (2) evaluate TEs effect on communities in the recipient river. Environmental biofilms were colonized in TEs and the recipient river up- and downstream from the WWTP output to study benthic diatoms using DNA metabarcoding combined with high-throughput sequencing (HTS). In parallel, concentrations of nutrients, pharmaceuticals and seasonal conditions were recorded. Diatom metabarcoding showed that benthic communities differed strongly in their diversity and structure depending on the habitat. TE sites were generally dominated by few genera with polysaprobic preferences belonging to the motile guild, while river sites favored diverse communities from oligotrophic and oligosaprobic groups. Seasonal changes were visible to lower extent. To categorize parameters important for diatom changes we performed redundancy analysis which suggested that communities within TE sites were associated to higher concentrations of beta-blockers and non-steroidal anti-inflammatory drugs in urban effluents vs. antibiotics and orthophosphate in hospital effluents. Furthermore, indicator species analysis showed that 27% of OTUs detected in river downstream communities were indicator for urban or hospital TE sites and were absent in the river upstream. Finally, biological diatom index (BDI) calculated to evaluate the ecological status of the recipient river suggested water quality decrease linked to the release of TEs. Thus, in-depth assessment of diatom community composition using DNA metabarcoding is proposed as a promising technique to highlight the disturbing effect of pollutants in Alpine rivers.

Epilithic biofilms are communities of microorganisms composed mainly of microbial cells, extracellular polymeric substances from the metabolism of microorganisms, and inorganic materials. Biofilms are a useful tool to assess the impact of anthropic action on aquatic environments including the presence of pesticide residues such as glyphosate. The present work seeks to monitor the occurrence of glyphosate and AMPA residues in epilithic biofilms occurring in a watershed. For this, epilithic biofilm samples were collected in the Guaporé River watershed in the fall and spring seasons of 2016 at eight points. Physicochemical properties of the water and biofilms were determined. The determination of glyphosate and AMPA was performed using an ultra-high performance liquid chromatograph coupled to a tandem mass spectrometer. The concentrations of glyphosate and AMPA detected in epilithic biofilms vary with the season (from 90 to 305 μg kg−1 for glyphosate and from 50 to 240 μg kg−1 for AMPA, in fall and spring, respectively) and are strongly influenced by the amount of herbicide applications. Protected locations and those with poor access not demonstrate the presence of these contaminants. In the other seven points of the Guaporé River watershed, glyphosate was detected in concentrations ranging from 10 to 305 μg kg−1, and concentrations of AMPA ranged from 50 to 670 μg kg−1. An overview of the contamination in the Guaporé watershed shows that the most affected areas are located in the Marau sub-watershed, which are strongly influenced by the presence of the city of Marau. This confirms the indiscriminate use of glyphosate in the urban area (weed control, domestic gardens and horticulture) and constitutes a problem for human and animal health. The results showed that biofilms can accumulate glyphosate resulting from the contamination of water courses and are sensitive to the sources of pollution and pesticides present in rivers. Fil: Fernandes, Gracieli. Universidade Federal de Santa Maria; Brasil Fil: Aparicio, Virginia Carolina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina Fil: Bastos, Marilia Camotti. Université de Lorraine; Francia Fil: de Gerónimo, Eduardo. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Sur. Estación Experimental Agropecuaria Balcarce. Área de Investigación en Agronomía; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina Fil: Labanowski, Jérôme. Université de Poitiers; Francia Fil: Prestes, Osmar Damian. Universidade Federal de Santa Maria; Brasil Fil: Zanella, Renato. Universidade Federal de Santa Maria; Brasil Fil: dos Santos, Danilo Rheinheimer. Universidade Federal de Santa Maria; Brasil

International audience; The 2.1‐billion‐year‐old (Ga) Francevillian series in Gabon hosts some of the oldest reported macroscopic fossils of various sizes and shapes, stimulating new debates on the origin, evolution and organization of early complex life. Here, we document ten representative types of exceptionally well‐preserved mat‐related structures, comprising “elephant‐skin” textures, putative macro‐tufted microbial mats, domal buildups, flat pyritized structures, discoidal microbial colonies, horizontal mat growth patterns, wrinkle structures, “kinneyia” structures, linear patterns and nodule‐like structures. A combination of petrographic analyses, scanning electron microscopy, Raman spectroscopy and organic elemental analyses of carbon‐rich laminae and microtexture, indicate a biological origin for these structures. The observed microtextures encompass oriented grains, floating silt‐sized quartz grains, concentrated heavy minerals, randomly oriented clays, wavy‐crinkly laminae and pyritized structures. Based on comparisons with modern analogues, as well as an average δ13C organic matter (Corg) composition of −32.94 ± 1.17‰ (1 standard deviation, SD) with an outlier of −41.26‰, we argue that the mat‐related structures contain relicts of multiple carbon pathways including heterotrophic recycling of photosynthetically derived Corg. Moreover, the relatively close association of the macroscopic fossil assemblages to the microbial mats may imply that microbial communities acted as potential benthic O2 oases linked to oxyphototrophic cyanobacterial mats and grazing grounds. In addition, the mat's presence likely improved the preservation of the oldest large colonial organisms, as they are known to strongly biostabilize sediments. Our findings highlight the oldest community assemblage of microscopic and macroscopic biota in the aftermath of the “Great Oxidation Event,” widening our understanding of biological organization during Earth's middle age.

International audience; Sorption of pharmaceuticals onto sediments is frequently related to organic matter content. Thus, the present work aimed to compare the effect of humic substances (HS) extracted from a river sediment versus Aldrich (HS) on the sorption of selected pharmaceuticals onto this river sediment. The results exhibited no “unique” effect of the presence of HS from the same origin. Thus, the sediment HS increased the sorption of sulfamethoxazole (SMX), diclofenac (DCF), and trimethoprim (TMP), but reduced the sorption of atenolol (ATN). The presence of Aldrich HS increased the sorption of TMP and ATN and decreased the sorption of SMX and DCF. Fluorescence quenching measurements revealed that these effects cannot be explained only by the presence of pharmaceutical HS associations. The use of several sorption models suggested that the sorption of SMX, DCF, and ATN involves multilayer mechanisms. Furthermore, it was pointed out that the presence of HS does not change the sorption mechanisms although it was observed interaction between HS and the sediment. Indeed, the sediment HS sorbs onto the sediment whereas the Aldrich HS tends to mobilize organic compounds from the sediment to the solution.

The work was done in collaboration with V. Lecomte (GRAIE). We thank B. Montuelle, F. Rimet, R. Sommaruga, and anonymous reviewers for their constructive comments on the manuscript.; International audience; Wastewater treatment plants (WWTP) are the main sources of a broad spectrum of pharmaceuticals found in freshwater ecosystems. These pollutants raise environmental health concerns because of their highly bioactive nature and their chronic releases. Despite this, pharmaceuticals' effects on aquatic environments are poorly defined. Biofilms represent a major part of the microbial life in rivers and streams. They can drive key metabolic cycles and their organizations reflect exposures to changing chemical, physical, and biological constraints. This study estimated the concentrations, over a 3-year period, of ten pharmaceuticals and five nutrients in a river contaminated by a conventional WWTP fed by urban and hospital wastewaters. Variations in these concentrations were related to biofilm bacterial community dynamics. Rock biofilms had developed over defined periods and were harvested at four locations in the river from the up- and downstream WWTP discharge point. Pharmaceuticals were found in all locations in concentrations ranging from not being detected to 192 ng L-1. Despite the high dilution factor of the WWTP effluents by the receiving river, pharmaceuticals were found more concentrated downstream than upstream the WWTP. Shifts in bacterial community structures linked to the environmental emission of pharmaceuticals were superior to seasonal community changes. A community structure from a site located downstream but close to the WWTP was more strongly associated with high pharmaceutical loads and different from those of biofilm samples from the WWTP upstream or far downstream sites. These latter sites were more strongly associated with high nutrient contents. Low environmental concentrations of pharmaceuticals can thus be transferred from WWTP effluents to a connected stream and induce bacterial aquatic community changes over time.

International audience

Qualité des Milieux Naturels

International audience; Hospital wastewater (HWW) receives increasing attention because of its specific composition and higher concentrations of some micropollutants. Better knowledge of HWW is needed in order to improve management strategies and to ensure the preservation of wastewater treatment efficiency and freshwater ecosystems. This context pushed forward the development of a pilot study site named Site Pilote de Bellecombe (SIPIBEL), which collects and treats HWW separately from urban wastewater, applying the same conventional treatment process. This particular configuration offers the opportunity for various scientific investigations. It enables to compare hospital and urban wastewater, the efficiency of the two parallel treatment lines, and the composition of the resulting hospital and urban treated effluents, as well as the evaluation of their effects on the environment. The study site takes into account environmental, economic, and social issues and promotes scientific and technical multidisciplinary actions. ᅟ.

Présentation du projet ANTIBIO-TOOLS au comité de gestion de SIPIBEL (Site Pilote de Bellecombe)

International audience; Short-term variations of soil conditions affect the form, mobility and bioavailability of metal pollutants. Released metals migrate toward depth where they are intercepted or precipitate, leading to variable spatial metal distribution patterns, at a macro-, meso- and microscale. Studies at a mesoscale give access to trace metal (TM) associations induced by pedological processes. Although scarcely documented, such meso-scale studies represent an essential step for relevant environmental risk assessment, halfway between field- and molecular-scale investigations. We argued for such approach by performing optical microscopy and micro-X-ray fluorescence on thin sections from two soils, contaminated either by industrial zinc-smelter waste or by urban wastewater. Consistent correlation between key indicators of pedological processes (Fe, Mn, and Ca) and trace metals (Zn, Pb, and Cu) on some 20 elemental maps of TM-hosting soil constituents and pedofeatures reveal distinct coinciding localizations, illustrating TM-accumulation via interception or (co)-precipitation processes. Micromorphological interpretation of characteristic pedofeatures in subsurface horizons (crystals, argillans, ferrans, and mangans) containing significant amounts of TM provide valuable insight into the contaminant dynamics in terms of lixiviation, colloidal transport, redox conditions, or fungal activity. Our mesoscale approach stresses the importance of pedology-based sampling strategies, instead of systematic soil-depth sampling, for soil contamination research in natural ecosystems

International audience; During the 20th century, the local economy of the Upper Loire Basin (ULB) was essentially based on industrial coal mining extraction. One of the major French coal districts with associated urban/industrial activities and numerous coking/gas plants were developed in the Ondaine-Furan subbasins, two tributaries of the upper Loire main stream. To determine the compositional assemblage, the level and the potential sources of contamination, the historical sedimentary chronicle of the 16 US EPA priority polycyclic aromatic hydrocarbons (PAHs) has been investigated. PAH concentrations were determined using gas chromatography/mass spectrometry (GC/MS) in a dated core, sampled in the Villerest flood-control reservoir located downstream of the Ondaine-Furan corridor (OFC). The most contaminated sediments were deposited prior to 1983 (Σ16PAHs ca. 4429–13,348 ng/g) and during flood events (Σ16PAHs ca. 6380 ng/g – 1996 flood; 5360 ng/g – 2003 flood; 6075 ng/g – 2008 flood), especially in medium and high molecular weight PAHs. Among them, typical pyrogenic PAHs such as FLT, PYR, BbF and BaP were prevalent in most of the core samples. In addition, some PAHs last decade data is available from the Loire Bretagne Water Agency and were analyzed using high-performance liquid chromatography with postcolumn fluorescence derivatization (HPLC/FLD). These results confirm that the most highly contaminated sediments were found downstream of OFC (Σ16PAHs ca. 2264–7460 ng/g). According to the observed molecular distribution, PAHs are originated largely from high-temperature pyrolytic processes. Major sources of pyrogenic PAHs have been emphasized by calculation of specific ratios and by comparison to reported data. Atmospheric deposition of urban and industrial areas, wood combustion and degraded coal tar derived from former factories of coking/gas plants seem to be the major pyrogenic sources. Specifically, particular solid transport conditions that can occur during major flood events lead us to emphasize weathering of former contamination sources, such as more preserved coal tar.

International audience; The fate of tembotrione (TBT) and sulcotrione (SCT) during chlorination was investigated in this work. Chlorination kinetics of TBT and SCT were studied by using a continuous-flow reactor in the pH range 2-12 with an excess of total chlorine. Second-order reaction was observed and rate constants of 9.69 (+/- 0.15) x 10(3) M(-1)s(-1) for TBT and 9.48 (+/- 0.62) x 10(3) M(-1)s(-1) for SCT were obtained at pH 7. Intrinsic rate constants for the elementary reactions of chlorine species with neutral and deprotonated forms of TBT and SCT were also calculated, leading to the conclusion that the reaction between hypochlorous acid and the deprotonated form of the pesticide is predominant at neutral pH. Several degradation products during chlorination of TBT and SCT were identified by LC-MS/MS and a reaction pathway was proposed. Chlorine initially reacted on the a-carbon of the three carbonyl functional groups. This reaction initiated the well-known haloform reaction and produced chloroform as end-product. Molar yields of 0.99 mol CHCl3/mol and 0.91 mol CHCl3/mol were obtained for TBT and SCT, respectively at pH 7. Moreover, a toxicity evaluation using Vibrio fischeri was carried out to study the toxicity pattern during TBT and SCT chlorination. An increase in toxicity was observed but it could not be clearly assigned to the identified byproducts. (

International audience; Metallurgical activities can generate a huge amount of partially vitrified waste products which are either landfilled or recycled. Lead Blast Furnace (LBF) slags are often disposed of in the vicinity of metallurgical plants, and are prone to weathering, releasing potentially toxic chemical components into the local environment. To simulate natural weathering in a slag heap, bioweathering of these LBF slags was studied in the presence of a pure heterotrophic bacterial strain (Pseudomonas aeruginosa) and in a semi-flow through reactor with intermittent leachate renewal. The evolution of water chemistry, slag composition and texture were monitored during the experiments. The cumulative bulk release of dissolved Fe, Si, Ca and Mg doubled in the presence of bacteria, probably due to the release of soluble complexing organic molecules (e.g. siderophores). In addition, bacterial biomass served as the bioadsorbent for Pb, Fe and Zn as 70-80% of Pb and Fe, 40-60% of Zn released are attached to and immobilized by the bacterial biomass.

The manganese oxide birnessite adsorbed and catalyzed the transformation of the anthelminthic drug niclosamide (NIS) into 2-chloro-4-nitroaniline (CNA) and 5-chlorosalicylic acid (CSA) at acidic pH. The adsorption of NIS was fitted using a linear isotherm for all conditions and reaction times. Linear adsorption constant Kd was 103 000 L kg−1 at pH 5.0. The rate of transformation was first order with respect to both MnO2 and NIS. At pH 5.0, the second order rate constant was 3.3 (±0.3) × 10−1 M−1 s−1. The adsorption constants and the rates of transformation decreased when pH increased from 4.0 to 5.5 because of increasing electrostatic repulsions between both negatively charged manganese oxide surface (pHzpc = 2.5) and NIS (pKa = 6.38). The presence of natural organic matter (NOM) extracted from surface water also significantly decreased the adsorption and the rates of transformation of NIS. The rate of transformation decreased by a factor of 20 in presence of 1.6 mgC L−1 even though significant amounts of NIS were adsorbed onto MnO2. The interactions between NOM and NIS were investigated by using the fluorescence quenching method and would explain that NIS adsorbed on the surface of manganese oxide was stable in presence of NOM. Thus, hydrolysis catalyzed by manganese oxide is probably not an important process compared to biodegradation and adsorption because of the presence of organic matter and pH values usually >5.5 in aquatic environment.

International audience; Wastewater treatment plants (WWTPs) are one of the main sources of pharmaceutical residue in surface water. Epilithic biofilms were collected downstream from 12 WWTPs of various types and capacities to study the impacts of their discharge through the changes in biofilm composition (compared to a corresponding upstream biofilm) in terms of pharmaceutical concentrations and bacterial community modifications (microbial diversity and resistance integrons). The biofilm is a promising indicator to evaluate the impacts of WWTPs on the surrounding aquatic environment. Indeed, the use of biofilms reveals contamination hot spots. All of the downstream biofilms present significant concentrations (up to 965 ng/g) of five to 11 pharmaceuticals (among the 12 analysed). Moreover, the exposition to the discharge point increases the presence of resistance integrons (three to 31 fold for Class 1) and modifies the diversity of the bacterial communities (for example cyanobacteria). The present study confirms that the discharge from WWTPs has an impact on the aquatic environment.

Hospital effluents cause growing interest, as they may be an important contamination source of micro- and macropollutants to WWTP influents. These effluents are usually characterised by higher concentrations and greater diversity of pollutants compared to urban wastewater. However, in certain cases, hospital effluents may represent only a small fraction of the total WWTP influent. Several recent studies report that their contribution to WWTP influents is limited and they are only one of the important sources of micropollutants in the environment. Nevertheless, specific micropollutants may exhibit relatively high hospital contribution, which may cause environmental risks. Several other important sources of micropollutants (chronic medication, nursing home, outpatients, cattle, etc.) are released in urban wastewaters. These sources should not be neglected, because they represent an important load that may impact aquatic environments.

This study aims at comparing low-pressure membrane fouling obtained with two different secondary effluents at bench and pilot-scale based on the determination of two fouling indices: the total fouling index (TFI) and the hydraulically irreversible fouling index (HIFI). The main objective was to investigate if simpler and less costly bench-scale experimentation can substitute for pilot-scale trials when assessing the fouling potential of secondary effluent in large scale membrane filtration plants producing recycled water. Absolute values for specific flux and total fouling index for the bench-scale system were higher than those determined from pilot-scale, nevertheless a statistically significant correlation (r(2) = 0.63, α = 0.1) was obtained for the total fouling index at both scales. On the contrary no such correlation was found for the hydraulically irreversible fouling index. Advanced water characterization tools such as excitation-emission matrix fluorescence spectroscopy (EEM) and liquid chromatography with organic carbon detection (LC-OCD) were used for the characterization of foulants. On the basis of statistical analysis, biopolymers and humic substances were found to be the major contribution to total fouling (r(2) = 0.95 and r(2) = 0.88, respectively). Adsorption of the low molecular weight neutral compounds to the membrane was attributed to hydraulically irreversible fouling (r(2) = 0.67).

Introduction: Streptococcus gordonii is one of the pioneer colonizer of the oral cavity and may be isolated from dental unit waterlines (DUWL) mixed with saliva because of antiretraction valve dysfunction.Aims: The behavior of S. gordonii in tap-water and the influence of low saliva concentrations (0–10% v/v) on bacterial proliferation were investigated. We evaluated the effect of saliva on bacterial survival in tap-water in order to know if it could facilitate or not the biofilm formation in the context of DUWL.Materials and methods: S. gordonii’s (DL1) survival ability was evaluated in tap-water with or without saliva supplementation (0–10% v/v) at 20 °C and 27 °C. Whole unstimulated saliva (WUS) and artificial saliva (AS) were both tested in this study. A gas chromatography and mass spectrometry (GC/MS) analysis was performed on filtered lyophilized WUS and the effect of each AS’s components were evaluated on S. gordonii’s survival.Results: S. gordonii survived in tap-water no longer than: 24 h at 27 °C and 72 h at 20 °C; water supplementation with saliva induced the bacterial inoculum maintained at 20 °C (>1% v/v) and enabled bacteria to survive up to 7 days at 27 °C (≥5% v/v). Various most simples structural artificial saliva’s compounds (both proteic and carbohydrate) seemed participate to this survival improvement.Discussion: Even if saliva contains some antimicrobial agents like lysozyme, it can also have a positive effect on S. gordonii. Very few information are known on saliva’s compounds responsible of this effect.Conclusion: Saliva, even in low proportions (1–10% v/v), was able to facilitate the survival of S. gordonii in tap-water. Several of its components seem participate on this effect.

Rate constants between ozone and triketone herbicides, tembotrione and sulcotrione, were determined between pH 2 and 12. Both compounds are completely transformed within seconds by ozone under real water treatment conditions. A reaction pathway was proposed based on the identification of transformation products. Toxicity evaluation using Vibrio fischeri test showed that a residual toxicity remained even after degradation of the major by-products, but biodegradation significantly increased from 50% to 70% for molar ozone to pesticide ratios from 0 to 2. Thus, ozonation coupled with biological treatment would drastically reduce the risk associated to the presence of triketone herbicides.

National audience; La présence de résidus de médicaments et de nombreux autres produits en lien avec les activités médicales est toujours régulièrement observée dans les milieux aquatiques ainsi que dans les ressources utilisées pour la production d’eau potable. En ce sens, une vaste réflexion s’est développée autour du traitement spécifique des effluents d’établissements hospitaliers et plus largement des eaux usées urbaines. Une expérience est testée dans le site SIPIBEL, mis en place depuis 2011 dans la vallée de l’Arve (France).

Hospital wastewaters (HWW) contain wider spectrum and higher quantity of pharmaceuticals than urban wastewaters (UWW), but they are generally discharged in sewers without pretreatment. Since traditional urban wastewater treatment plants (WWTP) are not designed to treat HWWs, treated effluents may still contain pollutants that could impair receiving aquatic environments. Hence, a better understanding of the effect of pharmaceuticals in the environment is required. Biofilms are effective "biological sensors" for assessing the environmental effects of pharmaceuticals due to their ability to respond rapidly to physical, chemical and biological fluctuations by changes in their structure and composition. This study evaluated the efficiency of biological treatment with conventional activated sludge system performed parallel on HWW and UWW. Furthermore, six successive monthly colonizations of biofilms were done on autoclaved stones, placed in grid-baskets in the hospital treated effluents (HTE) and urban treated effluents (UTE). The biomass of these biofilms as well as the structure and diversity of their bacterial communities were investigated. Results showed better treatment efficiency for phosphate and nitrite/nitrate during the treatment of UWW. Pharmaceuticals from all investigated therapeutic classes (beta-blockers, nonsteroidal anti-inflammatory drugs, antibiotics, analgesics and anticonvulsants) were efficiently removed, except for carbamazepine. The removal efficiency of the antibiotics, NSAIDs and beta-blockers was higher during the treatment of HWW. HTE and UTE shaped the bacterial communities in different ways. Higher concentrations of pharmaceuticals in the HTE caused adapted development of the microbial community, leading to less developed biomass and lower bacterial diversity. Seasonal changes in solar irradiance and temperature, caused changes in the community composition of biofilms in both effluents. According to the removal efficiency of pharmaceuticals, the separate treatment was beneficial. However, their high concentrations in the HTE and the following adaptations of biofilm communities identify the importance of adapting wastewater treatment to specific hospital pollutants.

Persist-Env est un projet de recherche finance par l’Anses pour evaluer la persistance environnementale des medicaments et des bacteries pathogenes en sortie de station d’epuration. Le projet s’interesse notamment a l’impact de la mise en place de filiere individuelle d’epuration des effluents hospitaliers. Sipibel (pour « site pilote de Bellecombe », situe en Haute-Savoie) teste actuellement cette strategie de traitement sur les effluents du centre hospitalier Alpes-Leman. L’objectif est de developper des connaissances scientifiques et des connaissances operationnelles autour de la question de l’interet du traitement separatif.