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Stringent discharge regulations are encouraging researchers to create innovative and sustainable wastewater treatment solutions. Urine source separation (USS) is among the potent approaches that may reduce nutrient peak loads in the influent wastewater and improve nutrient recovery. A phenomenological model was used to simulate dynamic influent properties and predict the advantages gained from implementing USS in an urban water basin. Several scenarios were investigated assuming different levels of deployment: at the entire city, or specifically in office buildings for men's urine only, or for both men and women employees. The results confirmed that all scenarios of urine source separation offered benefits at the treatment plant in terms of reducing nitrogen influent load. The economic benefits in terms of reducing energy consumption for nitrification and decreasing methanol addition for denitrification were quantified, and results confirmed environmental advantages gained from different USS scenarios. Despite larger advantages gained from a global USS rate in an entire city, implementation of a specific USS in office buildings would remain more feasible from a logistical perspective. A significant benefit in terms of reducing greenhouse gas emissions is demonstrated and this was especially due to the high level of N2O emissions avoided in nitrifying biological aerated filter.

International audience; Since the COVID-19 outbreak has started in late 2019, SARS-CoV-2 has been widely detected in human stools and in urban wastewater. No infectious SARS-CoV-2 particles have been detected in raw wastewater until now, but it has been reported occasionally in human stools. This has raised questions on the fate of SARS-CoV-2 during wastewater treatment and notably in its end-product, wastewater treatment sludge, which is classically valorized by land spreading for agricultural amendment. In the present work, we focused on SARS-CoV-2 stability in wastewater treatment sludge, either during storage (4 °C, room temperature) or thermophilic anaerobic digestion (50 °C). Anaerobic digestion is one of the possible processes for sludge valorization. Experiments were conducted in laboratory pilots; SARS-CoV-2 detection was based on RT-quantitative PCR or RT-digital droplet PCR. In addition to SARS-CoV-2, Bovine Coronavirus (BCoV) particles were used as surrogate virus. The RNA from SARS-CoV-2 particles, inactivated or not, was close to the detection limit but stable in wastewater treatment sludge, over the whole duration of the assays at 4 °C (55 days) and at ambient temperature (∼20 °C, 25 days). By contrast, the RNA levels of BCoV and inactivated SARS-CoV-2 particles decreased rapidly during the thermophilic anaerobic digestion of wastewater treatment sludge lasting for 5 days, with final levels that were close to the detection limit. Although the particles’ infectivity was not assessed, these results suggest that thermophilic anaerobic digestion is a suitable process for sludge sanitation, consistent with previous knowledge on other coronaviruses.

International audience; Phosphorus (P) removal from the domestic wastewater is required to counter the eutrophication in receiving water bodies and is mandated by the regulatory frameworks in several countries with discharge limits within 1-2mgPL−1. Operating at higher sludge retention time (SRT) and higher biomass concentration than the conventional activated sludge process (CASP), membrane bioreactors (MBRs) are able to remove 70–98% phosphorus without addition of coagulant. In full-scale facilities, enhanced biological phosphorus removal (EBPR) is assisted by the addition of metal coagulant to ensure >95% P-removal. MBRs are successfully used for super-large-scale wastewater treatment facilities (capacity >100,000 m3d−1). This paper documents the knowledge of P-removal modeling from lab to full-scale submerged MBRs and assesses the existing mathematical models for P-removal from domestic wastewater. There are still limited studies involving integrated modeling of the MBRs (full/super large-scale), considering the complex interactions among biology, chemical addition, filtration, and fouling. This paper analyses the design configurations and the parameters affecting the biological and chemical P-removal in MBRs to understand the P-removal process sensitivity and their implications for the modeling studies. Furthermore, it thoroughly reviews the applications of bio-kinetic and chemical precipitation models to MBRs for assessing their effectiveness with default stoichiometric and kinetic parameters and the extent to which these parameters have been calibrated/adjusted to simulate the P-removal successfully. It also presents a brief overview and comparison of seven (7) chemical precipitation models, along with a quick comparison of commercially available simulators. In addition to advantages associated with chemical precipitation for P-removal, its role in changing the relative abundance of the microbial community responsible for P-removal and denitrification and the controversial role in fouling mitigation/increase are discussed. Lastly, it encompasses several coagulant dosing control systems and their applications in the pilot to full-scale facilities to save coagulants and optimize the P-removal performance.

International audience; The presence of SARS-CoV-2 RNA has been extensively reported at the influent of wastewater treatment plants (WWTPs) worldwide, and its monitoring has been proposed as a potential surveillance tool to early alert of epidemic outbreaks. However, the fate of the SARS-CoV-2 RNA in the treatment process of WWTP has not been widely studied yet; therefore, in this study, we aimed to evaluate the efficiency of treatment processes in reducing SARS-CoV-2 RNA levels in wastewater. The treatment process of three WWTPs of the Parisian area in France was monitored on six different weeks over a period of 2 months (from April 14 to June 9, 2021). SARS-CoV-2 RNA copies were detected using digital polymerase chain reaction (dPCR). Investigation on the presence of variants of concern (Del69-70, E484K, and L452R) was also performed. Additionally, SARS-CoV-2 RNA loads in the WWTPs influents were expressed as the viral concentration in per population equivalent (PE) and showed a good correlation with French public health indicators (incidence rate). SARS-CoV-2 RNA loads were notably reduced along the water treatment lines of the three WWTPs studied (2.5-3.4 log reduction). Finally, very low SARS-CoV-2 RNA loads were detected in effluents (non-detected in over half of the samples) which indicated that the potential risk of the release of wastewater effluents to the environment is probably insignificant, in the case of WWTPs enabling an efficient biological removal of nitrogen.

International audience; Biocidal substances are ubiquitous in urban areas; they are used as preservatives in daily products, building materials, and as domestic pesticides. Despite these facts, urban sources of biocides, contrary to agricultural inputs, have been overlooked in terms of environmental risk assessment. The overall objective of this communication is to explore the use of a stochastic approach to assess the impact of biocide urban discharges on the river contamination. Biocide contamination in surface waters up-and downstream the Paris conurbation was investigated. The urban origins of these biocides were explored by targeting wastewater treatment plant and combined sewer overflow discharges from comparable watersheds, and by assessing biocide mass loads (discharged and transiting in the river) using a stochastic approach based on Monte-Carlo simulations. The 18targeted biocides were all quantified, and several were found at concentrations that can present high risk for the aquatic ecosystem. An increase in biocide loads between up-and downstream the Paris conurbation for several molecules and the contribution of urban discharges to biocide loads towards the receiving waters were ascertained. The results illustrate the interest of a stochastic approach to quantify the uncertainty on the determined values from a realistic description of the variability of biocide concentrations.

International audience; Monitoring the removal of organic micropollutants (OMPs) in advanced wastewater treatment facilities requires expensive and time-consuming analytical methods that cannot be installed online. Spectroscopic techniques such as fluorescence excitation/emission spectroscopy were demonstrated to offer the potential for monitoring OMPs removal in conventional wastewater treatment plants or ozonation pilots but their application to activated carbon (AC) adsorption processes was only investigated at lab scale and not in real treatment facilities. In this study, indexes from fluorescence emission/excitation matrices (EEMs) were used to find correlations with the removal of 28 OMPs from a large-scale AC pilot in fluidized bed employed for wastewater advanced treatment, as well as from batch experiments. Differences in OMPs removal could be observed depending on the operational conditions (i.e. pilot or batch experiments, contact time, type of AC) and the physico-chemical properties of the molecules. 7 PARAFAC components were derived from the fluorescence EEMs of 60 samples obtained before and after adsorption. Positive correlations were obtained between the removal of fluorescence indexes and most OMPs, and correlation coefficients were much higher than the ones obtained with UV254, confirming the interesting potential of fluorescence spectroscopy to accurately monitor adsorption performances at the industrial scale. The highest correlation coefficients were obtained for OMPs having the best removals while the ones that were refractory to adsorption, as well as to interactions with DOM, exhibited weak correlations. These results suggest that interactions between OMPs and fluorescing DOM and their subsequent co-adsorption onto AC were at the origin of the correlations found. Lower correlations were also found for the most biodegradable OMPs, which indicated that the occurrence of biological effects could make the monitoring of these compounds more challenging.

Introduction Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the etiological agent of coronavirus disease (COVID-19). People infected with SARS-CoV-2 may exhibit no or mild non-specific symptoms; thus, they may contribute to silent circulation of the virus among humans. Since SARS-CoV-2 RNA can be detected in stool samples, monitoring SARS-CoV-2 RNA in waste water (WW) has been proposed as a complementary tool to investigate virus circulation in human populations. Aim To test if the quantification of SARS-CoV-2 genomes in WW correlates with the number of symptomatic or non-symptomatic carriers. Method We performed a time-course quantitative analysis of SARS-CoV-2 by RT-qPCR in raw WW samples collected from several major WW treatment plants in Greater Paris. The study period was 5 March to 23 April 2020, including the lockdown period in France (from 17 March). Results We showed that the increase of genome units in raw WW accurately followed the increase of human COVID-19 cases observed at the regional level. Of note, the viral genome could be detected before the epidemic grew massively (around 8 March). Equally importantly, a marked decrease in the quantities of genome units was observed concomitantly with the reduction in the number of new COVID-19 cases, 29 days following the lockdown. Conclusion This work suggests that a quantitative monitoring of SARS-CoV-2 genomes in WW could generate important additional information for improved monitoring of SARS-CoV-2 circulation at local or regional levels and emphasises the role of WW-based epidemiology.

The Seine River basin (France) is representative of the large urbanised catchments (78,650 km2) located in Northwestern Europe. As such, it is highly impacted by anthropogenic activities and their associated emissions of pollutants such as polycyclic aromatic hydrocarbons (PAHs). These compounds, originating from household heating and road traffic, are responsible for serious environmental issues across the basin. This study aims at establishing and using mass balance analyses of PAHs at the Seine River basin scale as an efficient tool for understanding PAH pathways in the environment. A dual-scale approach (urban vs. rural areas) was used successfully, and mass balances provided useful knowledge on the environmental fate of PAHs. In urban areas, runoff and domestic and industrial discharges contributed similarly to the PAH supply to the sewer system. During the wastewater treatment process, PAHs were mainly eliminated through sludge removal. At the basin scale, substantial amounts of PAHs were quantified in soils, and the limited annual inputs and outputs through atmospheric deposition and soil erosion, respectively, suggest that these compounds have long residence times within the basin. While wastewater and runoff discharges from urban areas account for a substantial part of PAH urban fluxes to the Seine River, soil erosion seems to be the predominant contributor at the basin scale. Overall, the PAH flux at the basin outlet was greater than supplies, suggesting that the Seine River system may currently be undergoing a decontamination phase.

To tackle water micropollutant pollution, the development of an advanced wastewater treatment is necessary and should be supported by an environmental evaluation to guide decision-makers. Life cycle assessment (LCA) methodology has been applied in the literature for several technologies and highlighted the variability of results (e.g. site-specific conditions) and the limited (eco-)toxicity benefits compared to additional operating impacts. In this study, the LCA of an activated carbon (AC) adsorption process based on a fluidized bed (limiting AC usage) was performed to determine its optimal operating conditions (dosage, use of micro-grain – μGAC or powder – PAC) and environmental benefits compared to the common ozonation process. This study was based on pilot processes installed at the Seine Centre treatment plant (France), using sensitivity analyses to identify the conditions for choosing a technology. For the seven scenarios (fluidized bed with 10 and 20 mg/L, both for PAC and μGAC; ozonation with 0.6 and 0.9 gO3/gDOC; and pre-ozonation combined with μGAC), the operational impacts generated (energy and material use) and the impacts avoided (micropollutant removal) were evaluated for climate change, freshwater ecotoxicity and human toxicity (USEtox characterization factors for micropollutants complemented with literature data). The LCA results showed that the fluidized bed process should preferably be operated with μGAC rather than PAC. The advantage of μGAC adsorption compared to ozonation is negligible but could nevertheless be significant in European countries with a significant share of coal-based electricity (i.e. all countries except Sweden and France). As in most of the previous works, the (eco)toxicity impacts avoided were found to be negligible, but other substances, such as hormones and oxidation by-products, should be further considered and characterized to better represent the treatment performances. The combination of ozonation and μGAC adsorption on a fluidized bed is a promising option to efficiently remove micropollutants, as well as oxidation by-products, while keeping the impacts generated within a reasonable range. This paper presented valuable results to support the eco-design of advanced wastewater treatment (both in terms of operating conditions and targeted substances) but should be complemented with large-scale evaluations (e.g. using consequential LCA) and better impact characterization of micropollutants.

International audience; Highlights 17 • 7 commercial µGACs were characterized and tested with real wastewater 18 • A percentage of microporous volume higher than 65% reduced OMPs adsorption 19 • DOM reduced the adsorption of negatively-charged OMPs more than positive ones 20 • OMPs charge, hydrophobicity and minimal projection area influenced their adsorption 21 • The µGACs particle size had an impact on UV254 removal in continuous column tests 22 Graphical abstract 23 2 24 Abstract 25 Most studies dedicated to organic micropollutants (OMPs) removal from wastewater effluents by adsorption 26 onto activated carbon (AC) only consider a few conventional AC properties. The link between OMPs removal 27 and these properties is often missing, which limits the understanding of the adsorption process and the 28 interpretation of the results. The chemical, physical and textural properties of seven newly commercialized 29 micro-grain activated carbons (µGACs) were determined to assess their influence on the removal of 28 OMPs. 30 Conventional batch tests with wastewater effluent showed that a high percentage of microporous volume (> 31 65%) was detrimental for the removal of 10 OMPs, probably due to a higher blockage of micropores by 32 dissolved organic matter (DOM). The removal of 5 OMPs was correlated with µGACs surface chemistry 33 properties (i.e. charge) which were potentially modified by DOM adsorption or inorganic species, thus 34 favoring the adsorption of positively-charge compounds. A combination of OMPs properties including their 35 charge, hydrophobicity and minimal projection area could explain their removal. Correlations were found 36 between the removal of several OMPs and UV254 and dissolved organic carbon, suggesting that DOM and 37 OMPs interacted with each other or followed similar adsorption mechanisms. A decrease in µGACs particle 38 size had a positive impact on UV254 removal under continuous-flow conditions in columns representative of a 39 large-scale pilot due to better expansion. 40

International audience

International audience; Eighteen biocides used in building materials and domestic products were monitored in wastewater treatment plants (WWTPs) during dry weather and in combined sewer overflows (CSOs) during wet weather in the Paris conurbation. The aims of this study were to (i) acquire data on biocides in urban waters, which are very scarce up to now, (ii) identify their origins in CSOs with the perspective of reducing these contaminants at source, and (iii) compare and rank biocide pathways to the river (dry vs. wet weather) at the annual and conurbation scales. The results showed the ubiquity of the 18-targeted biocides in WWTP waters and CSOs. High concentrations of methylisothiazolinone, benzisothiazolinone (0.2-0.9 µg/L) and benzalkonium C12 (0.5-6 µg/L) were measured in wastewater. Poor WWTP removals (< 50%) were observed for most of the biocides. Both wastewater (mainly domestic uses) and stormwater (leaching from building materials) contributed to the CSO contamination. However, benzisothiazolinone mainly came from wastewater whereas diuron, isoproturon, terbutryn, carbendazim, tebuconazole, and mecoprop mainly came from stormwater. Annual mass loads discharged by WWTPs and CSOs into the Seine River were estimated using a stochastic approach (Monte Carlo simulations) at the conurbation scale and showed that WWTP discharges are the major entry pathway.

International audience; Advanced processes for the removal of organic micropollutants (OMPs) from wastewater effluents include adsorption onto activated carbon, ozonation, or a combination of both processes. The removal of 28 OMPs present in a real wastewater effluent was studied by ozonation coupled to activated carbon adsorption and compared to a sole adsorption. The influence of the specific ozone dose (0.09–1.29 gO3/gDOC) and the influence of the powdered activated carbon (PAC) dose (2, 5 and 10 mg/L) were first studied separately. OMPs removal increased with both the specific ozone dose (up to 80% for a dose higher than 0.60 gO3/gDOC) and the PAC dose. Ozonation performances decreased in presence of suspended solids, which were converted to dissolved organic carbon. A correction of the specific ozone dose according to the suspended solids levels, in addition to nitrite, should be considered. The influence of ozonation (0.09, 0.22, 0.94 and 1.29 gO3/gDOC) on OMPs adsorption was then assessed. OMPs adsorption didn’t change at low specific ozone doses but increased at higher specific ozone doses due to a decrease in DOM adsorption and competition with OMPs. At low ozone doses followed by adsorption (0.22 gO3/gDOC and 10 mg/L PAC), the two processes appeared complementary as OMPs with a low reactivity toward ozone were well absorbed onto PAC while most OMPs refractory to adsorption were well eliminated by ozone. Improved removals were obtained for all compounds with these selected doses, reaching more than 80% removal for most OMPs while limiting the formation of bromate ion.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [ADD1_IRSTEA]Valoriser les effluents et déchets organiques; International audience; Nitrifying biologically active filters (BAFs) have been found to be high emitters of nitrous oxide (N2O), a powerful greenhouse gas contributing to ozone layer depletion. While recent models have greatly improved our understanding of the triggers of N2O emissions from suspended-growth processes, less is known about N2O emissions from full-scale biofilm processes.Tertiary nitrifying BAFs have been modeled at some occasions but considering strong simplifications on the description of gas-liquid exchanges which are not appropriate for N2O prediction. In this work, a tertiary nitrifying BAF model including the main N2O biological pathways was developed and confronted to full-scale data from Seine Aval, the largest wastewater resource recovery facility in Europe. A mass balance on the gaseous compounds was included in order to correctly describe the N2O gas-liquid partition, thus N2O emissions. Preliminary modifications of the model structure were made to include the gas phase as a compartment of the model, which significantly affected the prediction of nitrification. In particular, considering gas hold-up influenced the prediction of the hydraulic retention time, thus nitrification performances: a 3.5% gas fraction reduced ammonium removal by 13%, as the liquid volume, small in such systems, is highly sensitive to the gas presence. Finally, the value of the volumetric oxygen transfer coefficient was adjusted to successfully predict both nitrification and N2O emissions.

The authors would like to thank Céline Briand and Julien Pouillaude (SIAAP), Barbara Giroud (ISA) and Séverine Bareilles (Saur).; International audience; Several advanced treatments, such as ozonation or activated carbon adsorption, are currently considered for the removal of organic micropollutants (OMPs) in wastewater treatment plants (WWTP). However, little is known on the overall performances of a WWTP upgraded with those processes and the benefits provided regarding the elimination of multiple families of OMPs. In this study, 5 sampling campaigns were performed to determine the removal of 48 OMPs in a WWTP followed by an activated carbon pilot. The primary treatment had no effect on OMPs (removals 60%). The additional elimination provided by the advanced treatment was not significant (30%) for recalcitrant OMPs. Removals higher than 60% were obtained for all OMPs (except azithromycin and sulfamethoxazole) over the WWTP and the activated carbon pilot. The adsorption conditions (10 g/m3 fresh activated carbon addition) were not sufficient to achieve the 80% removal targeted in Switzerland for compounds suggested as indicator substances for wastewater treatment. A higher dose of activated carbon or the combination with another advanced treatment should be used to achieve a satisfactory removal of those compounds.

International audience; The presence of dissolved organic matter (DOM) in wastewater effluents is recognized as the main factor limiting the adsorption of organic micropollutants (OMPs) onto activated carbon. The degree of the negative effect that DOM, depending on its quality, exerts on OMPs adsorption is still unclear. The influence of the interactions between DOM and OMPs on their removal is also not fully understood. Adsorption isotherms and conventional batch tests were performed in ultra-pure water and in wastewater effluent to study the influence of DOM on the adsorption of 12 OMPs onto powdered activated carbon. Best fit of adsorption pseudo-isotherms was obtained with the Freundlich equation and showed, as expected, that OMPs adsorption was higher in ultra-pure water than in wastewater effluent due to the presence of DOM leading to pore blockage and competition for adsorption sites. LC-OCD analysis revealed that biopolymers and hydrophobic molecules were the most adsorbed fractions while humic acids were not removed after a contact time of either 30 min or 72 h. The presence of DOM had a negative impact on the removal of all OMPs after 30 min of adsorption, but similar removals to ultra-pure water were obtained for 6 OMPs after 72 h of adsorption. This demonstrated that competition between DOM and OMPs for adsorption sites was not a major mechanism as compared to pore blockage, which only slowed down the adsorption and did not prevent it. The charge of OMPs had a clear impact: the adsorption of negatively charged compounds was reduced in the presence of wastewater effluent due to repulsive electrostatic interactions with the adsorbed DOM and the PAC surface. On the other hand, the removal of positively charged compounds was improved. A 24 h pre-equilibrium between OMPs and DOM improved their removal onto PAC, which suggest that OMPs and DOM interacted in solution which decreased the negative effects caused by the presence of DOM, e.g. through co-adsorption of an OMP-DOM complex.

The authors gratefully acknowledge Céline Briand (SIAAP) for her technical assistance during the sampling campaigns and daily operation of the pilot system.; International audience; Among the release solutions for reducing the discharge of organic and persistent contaminants in the aquatic environment, the use of a tertiary treatment in addition to existing conventional wastewater treatment processes is considered. The use of micro-grain activated carbon in a fluidized bed is a promising technique investigated in this study. The effluents from a large-scale pilot system were analyzed by liquid chromatography coupled with high-resolution mass spectrometry (QToF). Several strategies were deployed, namely molecular fingerprint comparison, suspected and non-target analyses, identification of refractory compounds to treatment, and finally, quantification of identified compounds. The evaluation of the molecular fingerprints provided evidence of the overall effect of the tertiary treatment on the treated wastewater quality. The suspected approach highlighted the presence of 83 pharmaceuticals and pesticides as well as transformation products in the effluents. The non-target approaches also highlighted compounds refractory to tertiary treatment, such as illicit drugs or some pharmaceuticals. The identification and quantification of identified compounds underscored the suitability of micro-grain activated carbon in eliminating many classes of pharmaceuticals with various physicochemical properties, such as anti-hypertensive, analgesic, anti-viral, antidepressant and even various pesticides.

International audience; The recent popularity of post-denitrification processes in the greater Paris area wastewater treatmentplants has caused a resurgence of the presence of nitrite in the Seine River. Controlling the productionof nitrite during the post-denitrification process has thus become a major technical issue. Researchstudies have been led in the MOCOPEE program (www.mocopee.com) to better understand theunderlying mechanisms behind the production of nitrite during wastewater denitrification and todevelop technical tools (measurement and control solutions) to assist on-site reductions of nitriteproduction. Prior studies have shown that typical methanol dosage strategies produce a varyingcarbon-to-nitrogen ratio in the reactor, which in turn leads to unstable nitrite concentrations in theeffluent. The possibility of adding a model-free control to the actual classical dosage strategy has thusbeen tested on the SimBio model, which simulates the behavior of wastewater biofilters. Thecorresponding “intelligent” feedback loop, which is using effluent nitrite concentrations, compensatesthe classical strategy only when needed. Simulation results show a clear improvement in averagenitrite concentration level and level stability in the effluent, without a notable overcost in methanol.; Le développement des unités de post-dénitrification dans les stations d'épuration de l'agglomération parisienne a fait ré-émerger la problématique du nitrite dans les eaux de Seine en aval de Paris. Le contrôle de l'apparition des nitrites au cours de l'étape de post-dénitrification est donc devenu un enjeu technique majeur. Des études visant à mieux appréhender les mécanismes d'apparition du nitrite lors de la dénitrification des eaux usées et à étudier des évolutions techniques (métrologie et boucles de contrôle-commande des procédés) à mettre en oeuvre sur les usines pour contrôler et limiter sa production ont été engagées dans le cadre du programme MOCOPEE (www.mocopee.com). De précédents travaux ont montré que les modes usuels d'injection du méthanol ne permettent pas de s'assurer de la stabilité du rapport C/N dans le réacteur biologique et conduisent à une production erratique et incontrôlée de nitrites. La possibilité d'ajouter une « commande sans modèle » à la commande classique a donc été testée à l'aide du modèle mathématique SimBio, modèle permettant de simuler le fonctionnement des unités de biofiltration. La commande sans modèle placée « en fin de traitement » et basée sur la concentration en nitrites mesurée en sortie de procédé, se greffe à la méthode de contrôle classique en y apportant des corrections seulement au besoin. Les résultats des simulations montrent qu'une régulation des injections de méthanol basée sur la « commande sans modèle » permet de stabiliser et maitriser le nitrite dans le rejet, sans induire d'augmentation des 1 quantités de méthanol injectées.

This study aims at determining how the boron signal of the Seine River evolved in terms of concentration and isotopic signatures over eighteen years (1994–95 and 2006–12) and if boron isotopes can reliably trace anthropogenic inputs over time. In the anthropised Seine River watershed, boron is widely released by human activities, and even if boron concentrations ([B]) are below the potability limit, our study confirms the potential of boron isotopes (δ11B) to trace urban anthropogenic contaminations. Between 1994 and 2012, [B] have decreased across the anthropised part of the Seine River basin (and by a factor of two in Paris) while δ11B has increased. This means either that urban inputs have been reduced or that the boron signature of urban inputs has changed over time. Both hypotheses are in agreement with the decrease of perborate consumption in Europe over 15 years and are not mutually exclusive. Results of a thorough analysis of urban effluents from the sewage network of Paris conurbation that are in fine released to the Seine River suggest a shift of the urban δ11B from −10‰ in 1994 to 1.5 ± 2.0‰ in 2012, in agreement with our second hypothesis. We attribute this change to the removal of perborates from detergents rather than to the modernisation of wastewater treatment network, because it does not significantly impact the wastewater boron signatures. Eighteen years after the first assessment and despite the decreased use of perborates, geochemical and isotopic mass budgets confirm, that boron in the Seine River basin is mainly released from urban activities (60–100%), especially in Paris and the downstream part of the basin. Contrastingly, in headwaters and/or tributaries with low urbanisation, the relative boron input to river from agricultural practices and rains increased, up to 10% and by 10 to 30%, respectively.

International audience; Sewage systems are a vital part of the urban infrastructure in most cities. They provide drainage, which protects public health, prevents the flooding of property and protects the water environment around urban areas. On some occasions sewers will overflow into the water environment during heavy rain potentially causing unacceptable impacts from releases of untreated sewage into the environment. In typical Life Cycle Assessment (LCA) studies of urban wastewater systems (UWS), average dry-weather conditions are modelled while wet-weather flows from UWS, presenting a high temporal variability, are not currently accounted for. In this context, the loads from several storm events could be important contributors to the impact categories freshwater eutrophication and ecotoxicity. In this study we investigated the contributions of these wet-weather-induced discharges relative to average dry-weather conditions in the life cycle inventory for UWS. In collaboration with the Paris public sanitation service (SIAAP) and Observatory of Urban Pollutants (OPUR) program researchers, this work aimed at identifying and comparing contributing flows from the UWS in the Paris area by a selection of routine wastewater parameters and priority pollutants. This collected data is organized according to archetypal weather days during a reference year. Then, for each archetypal weather day and its associated flows to the receiving river waters (Seine), the parameters of pollutant loads (statistical distribution of concentrations and volumes) were determined. The resulting inventory flows (i.e. the potential loads from the UWS) were used as LCA input data to assess the associated impacts. This allowed investigating the relative importance of episodic wet-weather versus “continuous” dry-weather loads with a probabilistic approach to account for pollutant variability within the urban flows. The analysis at the scale of one year showed that storm events are significant contributors to the impacts of freshwater eutrophication and ecotoxicity compared to those arising from treated effluents. At the rain event scale the wet-weather contributions to these impacts are even more significant, accounting for example for up to 88% of the total impact on freshwater ecotoxicity. This also allowed investigating and discussing the ecotoxicity contribution of each class of pollutants among the broad range of inventoried substances. Finally, with such significant contributions of pollutant loads and associated impacts from wet-weather events, further research is required to better include temporally-differentiated emissions when evaluating eutrophication and ecotoxicity. This will provide a better understanding of how the performance of an UWS system affects the receiving environment for given local weather conditions.

Due to severe mathematical modeling and calibration difficulties open-loop feedforward control is mainly employed today for wastewater denitrification, which is a key ecological issue. In order to improve the resulting poor performances a new model-free control setting and its corresponding "intelligent" controller are introduced. The pitfall of regulating two output variables via a single input variable is overcome by introducing also an open-loop knowledge-based control deduced from the plant behavior. Several convincing computer simulations are presented and discussed., Comment: IFAC 2017 World Congress, Toulouse, France

International audience; Although a higher oxidation rate for nitrite than for ammonia generally prevents nitrite accumulation in oxic waters, nitrite concentrations in the Seine River (1-31 mM) exceed European norms. We investigated the kinetics of in situ ammonia-and nitrite-oxidizing communities in river water and wastewater treatment plant (WWTP) effluents to determine the role of pelagic nitrification in the origin and persistence of nitrite downstream of Paris. The main source of nitrite is the major Parisian WWTP, and its persistence, up to tens of kilometers downstream of the plant, is explained by low ammonia and nitrite oxidation rates and high river flow. Furthermore, similar nitrite and ammonia oxidation rates preclude a rapid consumption of both preexisting nitrite and nitrite produced by ammonia oxidation. Maximum ammonia oxidation rates are two to three times higher downstream than upstream of the WWTP, indicating the input of ammonia oxidizers and ammonia from the WWTP. In both river water and WWTP effluents, nitrite oxidizers were unable to oxidize all available nitrite. In the human-impacted Seine River, this phenomenon might be due to mixotrophy. This study highlights the low resilience of the river to nitrite contamination as well as the importance of managing nitrite, nitrifiers, and organic matter concentrations in WWTP effluents to avoid nitrite persistence in rivers.

International audience; This article provides data on the contamination of different kinds of sludge (raw, centrifuged, digested, thermally dried sludge and sludge cake) from Paris conurbation by 71 various pollutants including pharmaceutical products (PHPs), hormones, perfluorinated acids (PFAs), linear alkylbenzene sulfonate (LAS), alkylphenols (APs), phthalates (PAEs), polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs).Very high contents of LAS (0.1–10g/kg dry matter - DM) compared to other compounds were found in all types of sludge followed by DEHP (10–100 mg/kg DM) and fluoroquinolones (1–100 mg/kg DM). APs were measured at intermediary contents in Parisian sludge, lying in the 2–20 mg/kg DM range. Finally, hormones, PAHs, PCBs, PAEs, PFAs and the remaining PHPs were all found at contents lower than 1 mg/kg DM.For most compounds (PHPs, PFOS, DEHP, PAHs), no significant differences in the micropollutant contents were found for similar types of sludge from different WWTP in Paris, highlighting the homogeneity of sludge contamination in downstream Paris catchment.The variability of concentration is rather high (coefficient of variation >100%) for several PHPs, PFAs or PCBs while it is moderate (

International audience; HIGHLIGHTS 18  BET surface and bulk density of activated carbons are correlated to micropollutants adsorption, 19  The activated carbon dose and the contact time have a great influence on adsorption, 20  FeCl3 has a positive influence on micropollutants adsorption by activated carbon (+10-15%), 21  Both the quantity and composition of organic matter impact the adsorption, 22  UV-254 removals are correlated to several micropollutants removals. 23 24 A Present adress: SIAAP, Direction du Développement et de la Prospective

International audience; This paper investigates the occurrence of alkylphenols (APs) and polybromodiphenylethers (PBDEs) in raw wastewater during dry and wet-weather periods, and their removal by physico-chemical lamellar settling and biofiltration techniques. Due to in-sewer deposit erosion and, to a lesser extent, to external inputs, raw effluents exhibit from 1.5 to 5 times higher AP and PBDE concentrations during wet periods compared with dry ones. The lamellar settler obtains high removal of APs and PBDEs under both dry and wet-weather flows (>53% for Σ(6)AP and >89% for Σ(4)PBDE), confirming the insensitivity of this technique to varying influent conditions. Indeed, despite the higher pollutant concentrations observed in raw effluents under wet-weather flows, adjusting the addition of coagulant-flocculent allows for efficient removal. By combining physical and biological processes, the biofiltration unit treats nutrient pollution, as well as Σ(6)AP and Σ(4)PBDE contamination (58 ± 5% and 75 ± 6% respectively). Although the operating conditions of the biofiltration unit are modified during wet periods, the performance in nutrient pollution, APs and light PBDE congeners remains high. Nevertheless, lower efficiency has been noted in nitrogen pollution, i.e. no denitrification occurs, and BDE-209 (not removed during wet-weather periods). In conclusion, this study demonstrates that the combination of both techniques treats AP and PBDE pollution efficiently during dry periods, but that they are also suitable for stormwater treatment.

International audience; The Cosmet'eau project (2015-2018) investigates the " changes in the personal care product (PCP) consumption practices: from whistle-blowers to impacts on aquatic environments. " In this project, the example of PCPs will be used to understand how public health concerns related to micropollutants can be addressed by public authorities – including local authorities –, industries and consumers. The project aims to characterize the possible changes in PCP consumption practices and to evaluate the impact of their implementation on aquatic contamination. Our goals are to study the whistle-blowers, the risk perception of consumers linked with their practices and the contamination in parabens and their substitutes, triclosan and triclocarban from wastewater to surface water. The project investigates the following potential solutions: modifications of industrial formulation or changes in consumption practices. The final purpose is to provide policy instruments for local authorities aiming at building effective strategies to fight against micropollutants in receiving waters.

Publication dans le cadre du programme OPUR; International audience; Among the solutions to reduce micropollutant discharges into the aquatic environment, activated carbon adsorption is a promising technique and a large scale pilot has been tested at the Seine Centre (240,000 m3/d — Paris, France) wastewater treatment plant (WWTP). While most of available works studied fixed bed or contact reactors with a separated separation step, this study assesses a new type of tertiary treatment based on a fluidized bed containing a high mass of activated carbon, continuously renewed. For the first time in the literature, micro-grain activated carbon (μGAC) was studied. The aims were (1) to determine the performances of fluidized bed operating with μCAG on both emerging micropollutants and conventional wastewater quality parameters, and (2) to compare its efficiency and applicability to wastewater to former results obtained with PAC. Thus, conventional wastewater quality parameters (n = 11), pharmaceuticals and hormones (PPHs; n = 62) and other emerging pollutants (n = 57) have been monitored in μGAC configuration during 13 campaigns.A significant correlation has been established between dissolved organic carbon (DOC), PPHs and UV absorbance at 254 nm (UV-254) removals. This confirms that UV-254 could be used as a tertiary treatment performance indicator to monitor the process. This parameter allowed identifying that the removals of UV-254 and DOC reach a plateau from a μGAC retention time (SRT) of 90–100 days.The μGAC configuration substantially improves the overall quality of the WWTP discharges by reducing biological (38–45%) and chemical oxygen demands (21–48%), DOC (13–44%) and UV-254 (22–48%). In addition, total suspended solids (TSS) are retained by the μGAC bed and a biological activity (nitratation) leads to a total elimination of NO2−.For micropollutants, PPHs have a good affinity for μGAC and high (> 60%) or very high (> 80%) removals are observed for most of the quantified compounds (n = 22/32), i.e. atenolol (92–97%), carbamazepine (80–94%), ciprofloxacin (75–95%), diclofenac (71–97%), oxazepam (74–91%) or sulfamethoxazole (56–83%). In addition, alkylphenols, artificial sweeteners, benzotriazole, bisphenol A, personal care products (triclocarban and parabens) and pesticides have removals lying in the 50 −> 90% range.Overall, the fluidized bed of μGAC allows obtaining performances comparable to PAC at the same activated carbon dose. Indeed, the average removal of the 13 PPHs found at a high occurrence (> 75%) in WWTP discharges is similar at 20 g/m3 of μGAC (78–89%) and PAC (85–93%). In addition, this recycled μGAC operation leads to several operational advantages (no FeCl3, reactivable, higher SRT, higher treated flow) and has a stronger impact on the overall wastewater quality compared to PAC.

International audience; The implementation of a tertiary treatment in conventional wastewater treatment plants is more and more considered by managers to reduce the emerging contaminant discharges into the aquatic environment. In this context, a collaboration between the public sanitation service of Paris conurbation and the Water Environment and Urban Systems laboratory has been initiated since 2013 to study at large scale a pilot (CarboPlus® - SAUR/STEREAU) based on a high concentration fluidized bed activated carbon reactor (>100 kg/m3) with continuous fresh activated carbon injection. The objectives of this project are to i) characterize the efficiency of the process for emerging pollutants for powdered (PAC) and micro-grain (µGAC) activated carbons, ii) characterize the parameters influencing the sorption mechanism (organic matter, operating parameters, activated carbon structure and properties, etc.) and iii) identify the eventual improvements of the conventional quality parameters.In addition to the 14 campaigns already performed in 2013 in PAC configuration, 14 campaigns have been planed in 2014 (8 already performed) to study the fate of 131 micropollutants, including 61 pharmaceuticals and hormones and 70 other emerging pollutants, in addition to conventional wastewater parameters. This presentation aims at displaying the pilot efficiency in µGAC configuration and comparing it to the PAC configuration. The use of µGAC instead of PAC has several operational and economical advantages, but this new type of carbon was never tested with wastewater. Based on the first 8 campaigns, the results tend to indicate that the pilot is as efficient with µGAC than with PAC. In particular, ketoprofen, paracetamol, ibuprofen, ofloxacin, ciprofloxacin, trimethoprim, roxithromycin, atenolol, propranolol, carbamazepine, oxazepam, lorazepam and estrone have removals higher than 80% in average. In addition, first results on the other emerging micropollutants show high or very high removals for pesticides (60-95%), bisphenol A (60-90%), alkylphenols (60-95%), PFOS (75-95%) and X-ray contrast agents (50-70%). Moreover, the high solid retention time (60-90 days) of the µGAC leads to a biological activity within the reactor, as displayed by NO2- (65-99%) and NH4+ (20-70%) removals. However, the results are still partial at this stage of the project, another µGAC dose is currently tested on the pilot and complementary lab-scale tests are still performed to better understand the sorption mechanism.

Environmental context Plastics production has increased considerably in recent years, leading to pollution by plastics, including microplastics (comprising particles smaller than 5mm). This work addresses the issue of microplastics from urban sources and in receiving waters in Greater Paris. Microplastics were found in all urban compartments investigated, namely atmospheric fallout, waste- and treated water, and surface water. Abstract This study investigates the microplastic contamination of both urban compartments (wastewater and total atmospheric fallout) and surface water in a continental environment. These first investigations on an urban environment confirm the presence of microplastics in sewage, fresh water and total atmospheric fallout and provide knowledge on the type and size distribution of microplastics in the 100–5000-µm range. For the first time, the presence of microplastics, mostly fibres, is highlighted in total atmospheric fallout (29–280particlesm–2day–1). High levels of fibres were found in wastewater (260–320×103particlesm–3). In treated effluent, the contamination significantly decreased to 14–50×103particlesm–3. In the River Seine, two sampling devices were used to collect both large and small microplastic particles: (i) a plankton net (80-µm mesh), and (ii) a manta trawl (330-µm mesh). Sampling with the plankton net showed a predominance of fibres, with concentrations ranging from 3 to 108particlesm–3. A greater diversity of both microplastic shapes and types was found during manta trawl sampling but at much lower concentrations (0.28–0.47particlesm–3). This combined approach could be relevant and implemented in future studies to provide an accurate overview of microplastic distribution in freshwater.

International audience; The objective of this study was to examine the occurrence of parabens (5 congeners), triclosan (TCS) and triclocarban (TCC) at the scale of the Parisian sewer network and to provide representative knowledge on these compounds in France for a large area. For this purpose and in collaboration with the Parisian public sanitation service (SIAAP) in charge of the collect and treatment of the Parisian wastewater, this study focused on seven main sewer trunks of the Paris conurbation, accounting for 1900,000 m(3) d(-1), i.e., about 8 million inhabitants. Concentrations lying in the 2000-20000 ng l(-1) ranges were found in wastewater, confirming the ubiquity of parabens, TCS and TCC in our environment and household products. Parabens (>97%) and to a lesser extent TCS (68% in median) were mainly associated to the dissolved fraction, as demonstrated by low KD and KOC values. For the first time, this study also evaluated the pollutant mass loads per population equivalent (PE) of parabens, TCS and TCC at the large and representative scale of the Parisian conurbation. Hence, the median mass loads varied from 176 to 3040 μg PE(-1) d(-1) for parabens and from 26 to 762 μg PE(-1) d(-1) for TCS and TCC. Based on these results and according to the assumptions done, the extrapolation of the mass loads at the national scale pointed out an annual mass loads between 51.8 and 100.7 ty(-1) for methyl paraben (MeP) and between 11.2 and 23.5 ty(-1) for TCS. Mass loads per equivalent habitant and national mass loads are both extremely relevant and innovative data. Contrary to other countries, such data are nowadays rather difficult to gain in France and neither enquiry nor database provides access to information on the use and production of these chemicals. Since cosmetic industries are voluntarily and fully engaged in the substitution of parabens, triclosan and triclocarban in personal care product, this study could constitute a "time reference status" which could be used as a basis for future monitoring.

International audience; : The microbiological quality of urban wastewaters presents important environmental, sanitary, and political challenges. However, the variability of untreated wastewater quality is seldom known when it comes to microbial parameters. This study aims to evaluate the variability of microbiological quality in wastewater influents from different wastewater treatment plants connected to combined and partially separate sewer networks in the Parisian area and to evaluate the impact of this variability on the treatment efficiency and on the accuracy of wastewater effluent monitoring. The densities of fecal indicator bacteria (FIB), Escherichia coli and intestinal enterococci, and their partitioning on settleable particles were analyzed at the inlet of two wastewater treatment plants during dry weather (130 composite samples and 7 days sampled every 2 hours) and storm events (39 composite samples, and 7 rain courses) from 2008 to 2012. The results showed that fecal indicator densities vary according to the network characteristics and according to the meteorological conditions. During storm events, a significant dilution of E. coli and enterococci was observed, as well as a decrease in the settleable fraction of E. coli during the maximal impact of the storm. However, storm events did not significantly impact the regular FIB monitoring. FIB removals by primary and secondary treatment were significantly correlated with FIB densities in influent wastewater; however, meteorological conditions also influenced the removal of FIB.

International audience; Chemical Engineering Journal Volume 211, 15 November 2012, Pages 293-301 Treatment of combined sewer overflows by ballasted flocculation: Removal study of a large broad spectrum of pollutants ( Articles not published yet, but available online Article in press About articles in press (opens in a new window) ) Gasperi, J.a , Laborie, B.b, Rocher, V.b a Université Paris-Est, LEESU, UMR MA 102, AgroParisTech, 61 Avenue du Gal de Gaulle, 94010 Créteil Cedex, France b SIAAP, Direction du Développement et de la Prospective, 82 Avenue Kléber, 92700 Colombes, France Abstract This study aims at examining the performance of the ballasted flocculation unit (BFU) on treating combined sewer overflows (CSOs) and the evaluation depends on the values obtained of routine wastewater parameters and on the contents of a large broad spectrum of pollutants. Accordingly, the full-scale BFU at the largest wastewater treatment plant in Europe (Seine Aval plant near Paris, France) is investigated during three sampling campaigns. Of the 97 molecules targeted, 57 substances including 18 priority substances and 11 priority hazardous substances were detected in the BFU influents confirming that wet weather flow (WWF) treatment has definitively proven to be necessary. The WWF treatment by ballasted flocculation appears as a promising but not a fully adapted technology for use in densely urbanized areas to considerably mitigate the CSO impacts. On operating at the optimal chemical and sand doses, this process appears to be a suitable technology to remove particles, carbonaceous and phosphorous pollutants, particulate metals and most of hydrophobic organic compounds whilst nitrogenous pollutants and most of hydrophilic compounds are from poorly (

International audience; Endocrine disrupting compounds (EDCs) have been found in surface waters worldwide. They are known for exerting adverse effects on animals of many species, including humans. EDCs comprise compounds of anthropogenic origin. They can enter waterways via either discharges from wastewater treatment plant (WWTPs), combined sewer overflows (CSO) or atmospheric deposition. In this work, the fate and removal of four phthalates and two alkylphenols: Diethyl phthalate (DEP), Di-n-Butyl phthalate (DnBP), Butyl Benzyl phthalate (BBP), Di-(2-ethylhexyl) phthalate (DEHP), nonylphenol (NP) and octylphenol (OP) were investigated within a wastewater treatment plant (WWTP) using lamellar clarification and biofiltration. This plant receives about 240,000 m 3 d -1 of wastewater. The whole treatment process comprises: screening, grit removal, primary sedimentation using coagulant and flocculant, followed by biofiltration units. Phthalates and alkylphenols were monitored at three locations, including raw sewage, before primary treatment, decanted effluents, before biological treatment, and final effluents, just before discharge to receiving waters. Nine campaigns were performed in 2011 during different seasons. In raw wastewater, DEHP was the major compound (32.42 to 71.88, median 42.95 μg.l -1), followed by DEP (7.00 to 36.03, median 21.00 μg.l -1) and NP (4.08 to 10.63, median 5.95 μg.l -1). Other compounds averaged few μg.l -1. During the WWTP treatment, DEP becomes major contaminant (0.46 to 6.77, median 2.95 μg.l -1), followed by DEHP (0.95 to 6.43, median 2.30 μg.l -1) and NP (0.31 to 1.36, median 0.63 μg.l -1). Contaminant removal depends on the physicochemical characteristics of the compounds. For example, for lamellar clarification, removal efficiency was found to be strongly dependent to log Kow and, hence, to be highly correlated with their sorption coefficient (Kd). As a consequence, compounds with high log Kow (>3) were removed to a significant extent. DEHP was highly removed by lamellar clarification (68.8%), followed by BBP (61.5%) and NP (51.0%). Besides, DEP (log Kow < 3) was slightly removed (13.8%). During biofiltration, both hydrophilic and hydrophobic compounds were equally eliminated. Therefore, DEP (87.3%), OP (88.0%) and DEHP (81.9%) were mostly removed during biological treatment. © 201 WIT Press.

International audience; This study evaluates the influence of a heavily urbanized area (Paris Metropolitan area), on receiving water contamination by both bisphenol A (BPA) and alkylphenol ethoxylate (APE) biodegradation product. The study began by investigating concentrations within urban sources. In addition to the more commonly studied wastewater treatment plant effluent, wet weather urban sources (including combined sewer overflows, urban runoff, and total atmospheric fallout) were considered. The initial results highlight a significant contamination of all urban sources (from a few nanograms per liter in atmospheric fallout to several micrograms per liter in the other sources) with clearly distinguishable distribution patterns. Secondly, concentration changes along the Seine River from upstream of the Paris Metropolitan area to downstream were investigated. While the concentrations of BPA and nonylphenoxy acetic acid (NP(1)EC) increase substantially due to urban sources, the 4-nonylphenol concentrations remain homogeneous along the Seine. These results suggest a broad dissemination of 4-nonylphenol at the scale of the Seine River basin. Moreover, the relationship between pollutant concentrations and Seine River flow was assessed both upstream and downstream of the Paris conurbation. Consequently, a sharp decrease in dissolved NP(1)EC concentrations relative to Seine River flow underscores the influence of single-point urban pollution on Seine River contamination. Conversely, dissolved 4-nonylphenol concentrations serve to reinforce the hypothesis of its widespread presence at the Seine River basin scale.

International audience; This work aims to compare the operation costs (energy, reagents, waste management) for the three layouts usually used in wastewater treatment plants incorporating biofilters, using technical and economical data acquired during 10 years of operation of a Parisian plant (Seine Centre, 240,000 m3 d−1 –800,000 equivalent inhabitants). The final objective is to establish general economical data and tendencies that can be translated from our study to any biofiltration plant. Our results evidenced the savings achieved through the treatment process combining upstream and downstream denitrification. To use this layout reduced the operating costs by some 10% as compared with conventional processing only comprising downstream denitrification. Operating costs were respectively estimated at 37 and 34 €/1,000 m3 for downstream denitrification and combining upstream and downstream denitrification layouts.

Postprint de l'article : Priority pollutants in urban stormwater in urban stormwater - Case of combined sewers. J. Gasperi, S. Zgheib, M. Cladière, V. Rocher, R. Moilleron, G. Chebbo. Water research, special issue on urban stormwater 2011; International audience; This study has evaluated the quality of combined sewer overflows (CSO) in an urban watershed, such as Paris, by providing accurate data on the occurrence of priority pollutants (PPs) and additional substances, as well as on the significance of their concentrations in comparison with wastewater and stormwater. Of the 88 substances monitored, 49 PPs were detected, with most of these also being frequently encountered in wastewater and stormwater, thus confirming their ubiquity in urban settings. For the majority of organic substances, concentrations range between 0.01 and 1 µg.l-1, while metals tend to display concentrations above 10 µg.l-1. Despite this ubiquity, CSO, wastewater and stormwater feature a number of differences in both their concentration ranges and pollutant patterns. For most hydrophobic organic pollutants and some particulate-bound metals, CSOs exhibit higher concentrations than those found in stormwater and wastewater, due to the contribution of in-sewer deposit erosion. For pesticides and Zn, CSOs have shown concentrations close to those of stormwater, suggesting runoff as the major contributor, while wastewater appears to be the main source of volatile organic compounds. Surprisingly, similar concentration ranges have been found for DEHP and tributyltin compounds in CSOs, wastewater and stormwater. The last section of this article identifies substances for which CSO discharges might constitute a major risk of exceeding Environmental Quality Standards in receiving waters and moreover indicates a significant risk for PAHs, tributyltin compounds and chloroalkanes. The data generated during this survey can subsequently be used to identify PPs of potential significance that merit further investigation.

International audience; One of the largest wastewater treatment plants in the Paris conurbation (240,000 m(3)/d) has been studied over several years in order to provide technical and economical information about biological treatment by biofiltration. Biofiltration systems are processes in which carbon and nitrogen pollution of wastewater are treated by ascendant flow through immersed fixed cultures. This paper, focused on technical information, aims: (1) to compare performances of the three biological treatment layouts currently used in biofiltration systems: upstream denitrification (UD), downstream denitrification (DD) and combined upstream-downstream denitrification (U-DD) layouts; and (2) to describe in detail each treatment step. Our study has shown that more than 90% of the carbon and ammoniacal pollution is removed during biological treatment, whatever the layout used. Nitrate, produced during nitrification, is then reduced to atmospheric nitrogen. This reduction is more extensive when the denitrification stage occurs downstream from the treatment (DD layout with methanol addition), whereas it is only partial when it is inserted upstream from the treatment (UD layout - use of endogenous carbonaceous substrate). So, the UD layout leads to a nitrate concentration that exceeds the regulatory threshold in the effluent, and the treatment must be supplemented with a post-denitrification step (U-DD layout). Our work has also shown that the optimal ammonium-loading rate is about 1.1-1.2 kg N-NH(4)(+) per m(3) media (polystyrene) and day. For denitrification, the optimal nitrate-loading rate is about 2.5 kg N per m(3) media (expanded clay) and day in the case of DD with methanol, and is about 0.25 kg N-NO(3)(-) per m(3) media and day in the case of UD with exogenous carbonaceous substrate.

International audience; Mycobacteria are waterborne emerging pathogens causing infections in human. Mycobacteria have been previously isolated from wastewater and sludge, but their densities were not estimated due to cultural biases. In order to evaluate the impact of wastewater treatment processes on mycobacteria removal, we used a real time PCR method. First we compared six DNA extraction methods and second we used the more efficient DNA extraction procedure (i.e., enzymatic lysis combined with hexadecyltrimethylammonium bromide-NaCl procedure) in order to quantify Mycobacterium. With the aim to identify parameters that could serve as indicator of mycobacterial behavior, mycobacterial densities were measured in parallel to those of Escherichia coli and enterococci, and to concentrations of chemical parameters usually monitored in wastewater. Mycobacterium reached 5.5 × 10⁵ ± 3.9 × 10⁵ copies/L in the influent, but was not detected in the effluent after decantation and biofiltration. Most mycobacteria (98.6 ± 2.7%, i.e. 2.4 ± 0.7 log₁₀) were removed by the physical-chemical decantation, and the remaining mycobacteria were removed by biofiltration. In contrast, enterococci and E. coli were lightly removed by decantation step and mainly removed by biofiltration. Our results showed that Mycobacterium corresponds to a hydrophobic behavior linked to insoluble compound removal, whereas enterococci and E. coli refer to hydrophilic behaviors linked to soluble compound removals.

Estrogens, which contribute greatly to the endocrine-disrupting activity in sewage, are partially sorbed onto particulate matter during sewage treatment. We thus investigated the occurrence of estrogens in different kinds of sludge and throughout a plant-scale anaerobic digestion process. The analytical method was first validated when sorption interaction between spiked estrogens and sludge could occur. Hence, the recovery ratio of estrone (E1), 17[beta]-estradiol (E2), estriol (E3) and 17[alpha]-ethinylestradiol (EE2) were determined when added to liquid sludge and mixed under various conditions. We show that minor non-extractable residues were formed (5-10%), suggesting that the sorption interaction established with sludge did not limit estrogen extraction. Estrogen concentrations measured in collected samples varied with sludge type. Secondary sludge showed higher E1 contents than primary sludge: respectively, 43 and 8 ng g-1 dry weight (dw). Two pathways of E1 production during secondary treatment are proposed to explain such a result. Higher estrogen concentrations were found in secondary sludge from a conventional plant (55 ng g-1 dw) compared to those from an advanced plant (13 ng g-1 dw). Based on estimated estrogen concentrations in sewage, we conclude that operating parameters play a role in the sorption of estrogens during secondary treatment. Also, the hydrophobic properties of the estrogens influenced the individual adsorption of each molecule. Thus, E3 showed the highest estimated concentrations in sewage but very low concentrations in sludge. Finally, plant-scale anaerobic digestion showed low efficiency (

International audience; This study investigates the occurrence of all priority substances (n = 41) listed in the Water Framework Directive and additional substances (n = 47) in raw sewage, as well as the removal performance of lamella clarification and biofiltration techniques. Once the efficiency of both types of techniques has been assessed for typical wastewater parameters, the differences in each technique's ability to remove pollutants becomes obvious; nevertheless, pollutant removal in quantitative terms still depends on the physico-chemical properties of the compounds used and operating conditions within the selected facility. For lamella clarification, the removal of organic chemicals was found to be primarily correlated with their sorption potential and, hence, strongly dependent upon log Kow of the compound under study. Compounds with a strong hydrophobic character (log Kow > 4.5) are removed to a significant extent (approx. 85%), while hydrophilic compounds (log Kow < 3.5) are poorly removed (< 20%). For biofiltration, the removal of chemicals appears to be compound-dependent, although this outcome involves several mechanisms, namely: i) physical filtration of total suspended solids, ii) volatilisation, iii) adsorption on biomass, and iv) biotransformation of substances. Even if the complex processes within a biofilter system do not yield an accurate prediction of pollutant removal, two groups of chemicals can still be clearly identified: i) hydrophobic or volatile compounds, for which moderate to high removal rates are observed (from 50% to over 80%); and ii) hydrophilic, non-volatile and refractory compounds for which a low removal rate would be expected (< 20%).