The main contents of campus sewage are BOD and inorganic nutrients. Conventional secondary treatment processes can remove BOD efficiently, whereas the inorganic nutrients remain mostly left. Therefore, the effluents may cause eutrophication to the receiving water bodies. Using constructed wetland treatment system to reduce nutrients become more and more popular recently. Vertical flow type subsurface process is particularly efficient in nitrogen transformations. In this research we studied the nitrogen transformation dynamics by using different types vertical flow constructed wetland system with various natural materials as the media to treat the secondary effluents from a campus sewage treatment plant. Six self designed experiment columns with broken concrete blocks, oyster shells, different sizes of marble granules, and river sands were used for this study as vertical flow constructed wetland systems. The methods of operation included batch type, continuous flow with filled water and trickling filter type, which were tested by controlling the influent flows into those six test columns. The efficiencies of various combinations in treatments and their mechanisms were discussed in the study. The experimental results showed that the best ammonium nitrogen removal efficiency was measured equal to 46.6% in batch type operations, while the continuous flow with filled water type operation showed the best performance by using concrete blocks as the media (42.8%). However, the best ammonium nitrogen removal rate in the trickling operation was found in the column with media of 3 mm marble granules (91.1%). The medium of river sand obtained the best phosphorous removal rate by using a batch flow operation. Vegetating presented only minor contributions in the column with medium of smaller grain size materials. The optimum C/N ratios for denitification tests are 3.5 and 3 by using the media of concrete and oyster, respectively.

French vertical-flow constructed wetlands (VFCW) directly treating raw wastewater are known to perform well on for SS, COD and nitrification. They are also known to robustly cope with hydraulic overloads during rainfall events. Although numerous systems have been installed in areas equipped with a combined sewer, the limits of stormwater acceptance remain ill-defined and need to be improved. Looking at the various VFCW designs and usages reported in the literature, it is difficult to draw any consensus on their hydraulic limits. Consequently, designing VFCW to accept hydraulic overloads is a complex task, as local context strongly impacts inlet flows produced during rainfall events. Dynamic models appear a requisite for filter design in such cases. Numerical CW models have essentially focused on horizontal flow, with few attempting to study VFCW dynamics which are more commonly tackled via mechanistic models. Although mechanistic models are powerful tools for describing processes within the VFCW, they are generally too complicated to be readily used by designers. The choice between detailed description and easy handling will depend on the modelling aims. If the aim is a global design tool, simplified models offer a good alternative. However, the simplified models geared to studying VFCW dynamics are extremely reduced. They are easy-handling for design and well-adapted to specific purposes (combined sewer overflow -CSO- treatment) but not necessarily to VFCW treating combined sewer wastewater, where long-term infiltration rates vary significantly. Consequently, this PhD thesis work focused on developing a simplified hydraulic model of VFCW to guide designers through the process of adapting VFCW systems to treat domestic wastewater in both dry and rain events. The simplified model makes it possible to link (i) hydraulics, by simulation of ponding time variations, (ii) biological performances, by establishing "dysfunction alerts" based on treatment performance assessment and variations in online N forms effluent from the young VFCW. These "dysfunction alerts" plot the maximal hydraulic load that a filter can accept without compromising its biological activity. The simplified model was used to model long-term hydraulics in the VFCW (i) to analyze the impact of local context and filter design on hydraulic overload acceptance (using "dysfunction alerts" and bypass discharges) and (ii) to propose VFCW designs for accepting hydraulic overload in different contexts. The modelling demonstrates that VFCW can limit days with bypass discharges to less than 20 times per year without jeopardizing filter performances. Moreover, the most problematic scenario on stormwater treatment remains a watershed with high imperviousness coefficient and low slope under a Bretagne-type climate, demonstrating that the filter is more sensitive to periodicity and duration than to intensity of rainfall events.

La gestion « durable » des ressources en phosphore est aujourd’hui un enjeu important du fait de l’épuisement des réserves naturelles et des besoins croissants de l’agriculture notamment. En parallèle, la protection des écosystèmes conduit à des réglementations de plus en plus strictes des rejets de phosphore. L’objectif scientifique de cette thèse est de contribuer à décrire les mécanismes de rétention et de libération du phosphore dans le cadre du traitement des eaux usées domestiques par filtres plantés de roseaux à écoulement vertical, notamment de mieux comprendre où et sous quelle forme le phosphore est retenu dans le système. Plus particulièrement, les travaux ont porté sur le procédé Azoé NP® proposé par la société française SCIRPE, lequel comprend un prétraitement biologique sur lit bactérien, une précipitation du phosphore par injection de chlorure ferrique, puis deux étages de filtres plantés de roseaux à écoulement vertical partiellement immergés. Dans une première phase, nous avons étudié la plus ancienne station de type Azoé NP® située à Vercia (Jura) qui a été suivie depuis 8 ans. Les résultats ont montré les bonnes performances du procédé et leur maintien sur le long terme malgré la forte augmentation de charge organique en automne provenant d’effluents viticoles. Il a été montré que le phosphore était principalement retenu au sein du premier filtre, essentiellement dans la couche de boues organiques qui se forme en surface du 1er étage. L’utilisation de techniques analytiques complémentaires a permis de montrer notamment que leur minéralisation progressive entrainait une évolution des espèces de phosphore au cours du temps, avec par exemple formation de phosphore apatitique. La rétention du phosphore dans les boues a ensuite été étudiée à l’échelle du laboratoire à l’aide de lixiviations successives dans des conditions extrêmes de pH ou d’oxydo-réduction. Les résultats ont montré une très bonne stabilité en conditions de fonctionnement normales. Des essais pilotes ont enfin été réalisés pour approfondir l’évaluation de l’influence du potentiel redox en faisant varier la hauteur d’immersion du milieu filtrant qui influence les conditions d’oxydoréduction. Ces études ont confirmé la stabilité des procédés Azoé NP® et Azoé P® (correspondant au procédé Azoé NP® sans zone d’immersion) en fonctionnement normal. En conditions d’immersion totale prolongée simulant un dysfonctionnement du système, les performances sont dégradées en une semaine, mais le retour en mode totalement insaturé permet un rétablissement très rapide indiquant la bonne résilience du système. / Nowadays, sustainable management of phosphorus resources is an important issue due to the depletion of natural reserves and growing of its agriculture need. In parallel, the protection of ecosystems leads to stringent regulations concerning treatment of phosphorus in wastewaters. The scientific objective of this thesis was to contribute to describing the phosphorus retention and release in domestic wastewater treatments by vertical flow constructed wetlands, especially to better understand where and in which form the phosphorus is retained in the system. In particular, the work focused on the process Azoé NP® proposed by the French company SCIRPE, which includes a biological pretreatment on trickling filter, precipitation of phosphorus by injection of ferric chloride and two stages of partially flooded vertical flow constructed wetland. First of all, we studied the oldest Azoé NP® type station located at Vercia (Jura, France) which was monitored for 8 years. The results showed that the Vercia treatment plant provided robust year-round treatment of municipal wastewater and winery wastewater during automn. It was found that the phosphorus was principally retained within the deposit organic sludge layer on the surface of the first stage of filteration. The use of additional analytical techniques showed that phosphates species within this deposit layer changed during the mineralization of organic matters over time. The formation of amorphous apatite species was also discussed. The stability of the retention of phosphorus in sludge was then studied at laboratory scale using successive leaching under extreme conditions of pH or redox potential. The results showed a very good stability of sludge from the Vercia plant in normal operating conditions. Pilot tests were finally performed to evaluate the influence water saturation level within the filter medium which affect redox conditions of the system. These studies confirmed the stability of processes Azoé NP® and Azoé P® (corresponding to the process Azoé NP® without water saturation within filter media) during normal operation. Under conditions of prolonged immersion simulating a malfunctionning of the system, the performance was degraded after one week of flooding. However, the return to fully unsaturated mode allowed a very fast recovery of the filter, showing a good resilience of the system.

Vertical flow constructed wetlands (VF CWs) are becoming increasingly popular for onsite wastewater treatment due to their high oxygen transfer capacity and high nitrification rates. However, there are still some question marks regarding (1) how the treatment performance of VF CWs is affected by design and operational parameters, and (2) the treatment processes happening inside the wetland bed as the wastewater percolates through. In this study, we investigated the effects of filter media (coarse sand or fine gravel), dosing regime (hourly with 4 mm or bi-hourly with 8 mm) and plant presence (with or without Phragmites australis) on the  treatment performance and concentration depth profiles of pollutant removal in six pilot-scale VF CWs treating primary treated domestic wastewater. Grab samples of wastewater were collected every 2-3 weeks during 5 months and analyzed for organic matter, suspended solids, nitrogen and E. coli. We found that sand beds performed better than gravel beds for removal of all pollutants except total nitrogen, although for long term operation gravel may be less susceptible to clogging. The overall treatment performance was not affected by different dosing regimes, but the concentration depth profiles showed that smaller and more frequent doses led to more pollutant removal in the upper part of the beds. The presence of plants was moderately important for the removal of ammonium, but had no effect on other pollutants.

A presente pesquisa avaliou duas alternativas para a remoção de fósforo em esgoto sanitário: uso de filtros percoladores com adição de material com potencial de ligação de fósforo e uso de banhados construídos com macrófitas com potencial assimilação de fósforo. Estas tecnologias são apropriadas para pequenas comunidades ou residências unifamiliares e também podem ser utilizadas como etapa no tratamento dos esgotos. Estes sistemas apresentam remoção satisfatória de matéria orgânica e nitrogênio amoniacal, contudo apresentam diminuta eficiência de remoção de fósforo e nitrato. Na presente pesquisa foram estudadas duas técnicas para aumentar a remoção de fósforo: utilização de materiais com potencial de remoção de fósforo nos filtros percoladores, e plantas com alta capacidade de assimilação de fósforo nos banhados construídos. Os materiais adicionados aos leitos percoladores com potencial de remoção de fósforo foram: Cavaco de Usinagem e Escória de Aciaria Elétrica. As frações de materiais adicionados foram: 10%, 20% e 40% em peso em relação ao material suporte. As plantas utilizadas foram a Luziola peruviana, a qual apresenta em sua constituição alta concentração de fósforo e a Typha latifolia, já amplamente utilizada em banhados construídos. Os materiais utilizados como meios suportes foram brita e areia. A adição de materiais com potencial remoção de fósforo auxiliou na remoção do nutriente, a qual foi mais significativa nos leitos contendo Cavaco de Usinagem. Não foi observada diferença de remoção de fósforo para as diferentes frações dos materiais testados para o período de estudo. A utilização da planta Luziola peruviana contribuiu no máximo com 2,11% da remoção de fósforo total, contudo foi observada importante função do sistema radicular no tempo de percolação, contribuindo para maior tempo de contato do efluente com material suporte, especialmente para o caso da brita. O uso de areia de granulometria grossa possibilitou eficiência de remoção de fósforo superior a 85%, entretanto, a massa de fósforo retida por unidade de área no sistema utilizando brita 0 apresentou valores duas vezes superiores aos obtidos para os leitos preenchidos com areia. / This research evaluated two alternatives to phosphorus removal from domestic wastewater: use of intermittent sand filters with materials addition with potential phosphorus binding and use of constructed wetlands with macrophytes potential phosphorus assimilation. These present themselves as technologies suitable for small communities or single family houses and can be used as a intermediate or final stage of wastewater treatment. The systems based on intermittent feed get satisfactory removal of organic matter and ammonia-N, but they have reduced efficiency of phosphorus and nitrate removal. The aim of present study was to evaluate two techniques for phosphorus removal: use of materials with potential removal of phosphorus, in the intermittent sand filters, and plants with capacity for assimilation of phosphorus metabolism, in the vertical flow constructed wetlands. The materials added to the sand filters with the potential removal of phosphorus were the Machine Bit and Electric Arc Furnace Slag. The fractions of materials added were: 10%, 20% and 40% related to material support weight. The plants tested were Luziola peruviana, which has in its constitution a high concentration of phosphorus and Typha latifolia, widely used in constructed wetlands. The support materials tested were gravel and sand. The use of materials with potential removal of phosphorus aid in the removal of phosphorus, which is more significant in the beds with Machine Bit. Difference of phosphorus removal was not observed for the different fractions of the materials tested for the study period. The use of the plant Luziola peruviana contributed at the most with 2,11% of removal of total phosphorus, however important role of the root system was observed in the percolation time, contributing to larger time of contact of wastewater with support materials, especially for use of coarse material, as it the coarse gravel. The use of coarse sand allowed removal efficiency of phosphorus higher than 85%, however, the mass of phosphorus retained per unit area in the system using gravel present values twice higher than obtained to the beds filled with sand.

A presente pesquisa avaliou duas alternativas para a remoção de fósforo em esgoto sanitário: uso de filtros percoladores com adição de material com potencial de ligação de fósforo e uso de banhados construídos com macrófitas com potencial assimilação de fósforo. Estas tecnologias são apropriadas para pequenas comunidades ou residências unifamiliares e também podem ser utilizadas como etapa no tratamento dos esgotos. Estes sistemas apresentam remoção satisfatória de matéria orgânica e nitrogênio amoniacal, contudo apresentam diminuta eficiência de remoção de fósforo e nitrato. Na presente pesquisa foram estudadas duas técnicas para aumentar a remoção de fósforo: utilização de materiais com potencial de remoção de fósforo nos filtros percoladores, e plantas com alta capacidade de assimilação de fósforo nos banhados construídos. Os materiais adicionados aos leitos percoladores com potencial de remoção de fósforo foram: Cavaco de Usinagem e Escória de Aciaria Elétrica. As frações de materiais adicionados foram: 10%, 20% e 40% em peso em relação ao material suporte. As plantas utilizadas foram a Luziola peruviana, a qual apresenta em sua constituição alta concentração de fósforo e a Typha latifolia, já amplamente utilizada em banhados construídos. Os materiais utilizados como meios suportes foram brita e areia. A adição de materiais com potencial remoção de fósforo auxiliou na remoção do nutriente, a qual foi mais significativa nos leitos contendo Cavaco de Usinagem. Não foi observada diferença de remoção de fósforo para as diferentes frações dos materiais testados para o período de estudo. A utilização da planta Luziola peruviana contribuiu no máximo com 2,11% da remoção de fósforo total, contudo foi observada importante função do sistema radicular no tempo de percolação, contribuindo para maior tempo de contato do efluente com material suporte, especialmente para o caso da brita. O uso de areia de granulometria grossa possibilitou eficiência de remoção de fósforo superior a 85%, entretanto, a massa de fósforo retida por unidade de área no sistema utilizando brita 0 apresentou valores duas vezes superiores aos obtidos para os leitos preenchidos com areia. / This research evaluated two alternatives to phosphorus removal from domestic wastewater: use of intermittent sand filters with materials addition with potential phosphorus binding and use of constructed wetlands with macrophytes potential phosphorus assimilation. These present themselves as technologies suitable for small communities or single family houses and can be used as a intermediate or final stage of wastewater treatment. The systems based on intermittent feed get satisfactory removal of organic matter and ammonia-N, but they have reduced efficiency of phosphorus and nitrate removal. The aim of present study was to evaluate two techniques for phosphorus removal: use of materials with potential removal of phosphorus, in the intermittent sand filters, and plants with capacity for assimilation of phosphorus metabolism, in the vertical flow constructed wetlands. The materials added to the sand filters with the potential removal of phosphorus were the Machine Bit and Electric Arc Furnace Slag. The fractions of materials added were: 10%, 20% and 40% related to material support weight. The plants tested were Luziola peruviana, which has in its constitution a high concentration of phosphorus and Typha latifolia, widely used in constructed wetlands. The support materials tested were gravel and sand. The use of materials with potential removal of phosphorus aid in the removal of phosphorus, which is more significant in the beds with Machine Bit. Difference of phosphorus removal was not observed for the different fractions of the materials tested for the study period. The use of the plant Luziola peruviana contributed at the most with 2,11% of removal of total phosphorus, however important role of the root system was observed in the percolation time, contributing to larger time of contact of wastewater with support materials, especially for use of coarse material, as it the coarse gravel. The use of coarse sand allowed removal efficiency of phosphorus higher than 85%, however, the mass of phosphorus retained per unit area in the system using gravel present values twice higher than obtained to the beds filled with sand.

A presente pesquisa avaliou duas alternativas para a remoção de fósforo em esgoto sanitário: uso de filtros percoladores com adição de material com potencial de ligação de fósforo e uso de banhados construídos com macrófitas com potencial assimilação de fósforo. Estas tecnologias são apropriadas para pequenas comunidades ou residências unifamiliares e também podem ser utilizadas como etapa no tratamento dos esgotos. Estes sistemas apresentam remoção satisfatória de matéria orgânica e nitrogênio amoniacal, contudo apresentam diminuta eficiência de remoção de fósforo e nitrato. Na presente pesquisa foram estudadas duas técnicas para aumentar a remoção de fósforo: utilização de materiais com potencial de remoção de fósforo nos filtros percoladores, e plantas com alta capacidade de assimilação de fósforo nos banhados construídos. Os materiais adicionados aos leitos percoladores com potencial de remoção de fósforo foram: Cavaco de Usinagem e Escória de Aciaria Elétrica. As frações de materiais adicionados foram: 10%, 20% e 40% em peso em relação ao material suporte. As plantas utilizadas foram a Luziola peruviana, a qual apresenta em sua constituição alta concentração de fósforo e a Typha latifolia, já amplamente utilizada em banhados construídos. Os materiais utilizados como meios suportes foram brita e areia. A adição de materiais com potencial remoção de fósforo auxiliou na remoção do nutriente, a qual foi mais significativa nos leitos contendo Cavaco de Usinagem. Não foi observada diferença de remoção de fósforo para as diferentes frações dos materiais testados para o período de estudo. A utilização da planta Luziola peruviana contribuiu no máximo com 2,11% da remoção de fósforo total, contudo foi observada importante função do sistema radicular no tempo de percolação, contribuindo para maior tempo de contato do efluente com material suporte, especialmente para o caso da brita. O uso de areia de granulometria grossa possibilitou eficiência de remoção de fósforo superior a 85%, entretanto, a massa de fósforo retida por unidade de área no sistema utilizando brita 0 apresentou valores duas vezes superiores aos obtidos para os leitos preenchidos com areia. / This research evaluated two alternatives to phosphorus removal from domestic wastewater: use of intermittent sand filters with materials addition with potential phosphorus binding and use of constructed wetlands with macrophytes potential phosphorus assimilation. These present themselves as technologies suitable for small communities or single family houses and can be used as a intermediate or final stage of wastewater treatment. The systems based on intermittent feed get satisfactory removal of organic matter and ammonia-N, but they have reduced efficiency of phosphorus and nitrate removal. The aim of present study was to evaluate two techniques for phosphorus removal: use of materials with potential removal of phosphorus, in the intermittent sand filters, and plants with capacity for assimilation of phosphorus metabolism, in the vertical flow constructed wetlands. The materials added to the sand filters with the potential removal of phosphorus were the Machine Bit and Electric Arc Furnace Slag. The fractions of materials added were: 10%, 20% and 40% related to material support weight. The plants tested were Luziola peruviana, which has in its constitution a high concentration of phosphorus and Typha latifolia, widely used in constructed wetlands. The support materials tested were gravel and sand. The use of materials with potential removal of phosphorus aid in the removal of phosphorus, which is more significant in the beds with Machine Bit. Difference of phosphorus removal was not observed for the different fractions of the materials tested for the study period. The use of the plant Luziola peruviana contributed at the most with 2,11% of removal of total phosphorus, however important role of the root system was observed in the percolation time, contributing to larger time of contact of wastewater with support materials, especially for use of coarse material, as it the coarse gravel. The use of coarse sand allowed removal efficiency of phosphorus higher than 85%, however, the mass of phosphorus retained per unit area in the system using gravel present values twice higher than obtained to the beds filled with sand.

Subject of this thesis is ecologic wastewater treatment with little organic load. Treated wastewater for infiltration must contain low values of nitrogen. This thesis is about to design two-stage subsurface vertical flow constructed wetland.

Les filtres plantés de roseaux à écoulement vertical (FPR-V) pour le traitement des eaux usées domestiques sont relativement bien développés en France et permettent de réaliser un traitement poussé de la matière carbonée et la nitrification. La robustesse de cette filière réside également dans sa capacité à accepter des surcharges hydrauliques en temps de pluie. Cependant ces limites d’acceptation hydraulique ne sont pas bien définies et demandent à être optimisées. La conception des FPR-V pour accepter des surcharges hydrauliques est un travail complexe car le contexte local affecte fortement les débits d’eau entrants dans la station lors d’un événement pluvieux. Dans de tels cas, la conception de filtres demande l’utilisation de modèles dynamiques. Ces modèles s’appuient le plus souvent sur une approche mécanistique et sont à l'origine conçus et utilisés pour la recherche. Cependant, si ces modèles sont des outils puissants pour décrire en détail la dynamique du FPR-V, ils sont généralement trop complexes à manipuler pour des utilisateurs non experts. Choisir entre une description détaillée et une manipulation facile dépendra des objectifs de modélisation. Quand des objectifs de dimensionnement global sont visés par les concepteurs, l'utilisation de modèles simplifiés semble une bonne alternative. Les modèles simplifiés sont faciles à utiliser pour la conception de FPR-V mais ils sont peu nombreux. Cependant ils sont adaptés à des configurations spécifiques liées au traitement des surverses de déversoirs d’orage, ce qui n’est pas le cas pour les FPR-V traitant des eaux usées domestiques. En effet, pour ce type de FPR-V les vitesses d’infiltration du système varient considérablement. En conséquence, ce travail de thèse a pour objectif de développer un modèle hydraulique simplifié des FPR-V qui permettra de guider les concepteurs dans le processus d’adaptation des FPR-V pour traiter les eaux usées domestiques des périodes de temps sec et de temps de pluie. Le modèle simplifié permet de relier (i) l’hydraulique du filtre, en simulant le temps de noyage à la surface, et (ii) les performances biologiques, en établissant des «alertes de dysfonctionnement », basées sur l'évaluation des performances épuratoires et sur les variations des formes azotées à la sortie du filtre mesurées en continu. Les «alertes de dysfonctionnement» représentent la charge hydraulique maximale qu'un filtre peut accepter sans compromettre son activité biologique. Le modèle simplifié a été utilisé pour la modélisation hydraulique du FPR-V à long terme (i) pour analyser l’impact du contexte local et la conception du filtre dans l’acceptation de surcharges hydrauliques. Grâce à cet analyse, (ii) on peut proposer les dimensionnements de FPR-V qui arrivent à mieux gérer l’acceptation des surcharges hydrauliques. / French vertical-flow constructed wetlands (VFCW) directly treating raw wastewater are known to perform well on for SS, COD and nitrification. They are also known to robustly cope with hydraulic overloads during rainfall events. Although numerous systems have been installed in areas equipped with a combined sewer, the limits of stormwater acceptance remain ill-defined and need to be improved. Looking at the various VFCW designs and usages reported in the literature, it is difficult to draw any consensus on their hydraulic limits. Consequently, designing VFCW to accept hydraulic overloads is a complex task, as local context strongly impacts inlet flows produced during rainfall events. Dynamic models appear a requisite for filter design in such cases. Numerical CW models have essentially focused on horizontal flow, with few attempting to study VFCW dynamics which are more commonly tackled via mechanistic models. Although mechanistic models are powerful tools for describing processes within the VFCW, they are generally too complicated to be readily used by designers. The choice between detailed description and easy handling will depend on the modelling aims. If the aim is a global design tool, simplified models offer a good alternative. However, the simplified models geared to studying VFCW dynamics are extremely reduced. They are easy-handling for design and well-adapted to specific purposes (combined sewer overflow -CSO- treatment) but not necessarily to VFCW treating combined sewer wastewater, where long-term infiltration rates vary significantly. Consequently, this PhD thesis work focused on developing a simplified hydraulic model of VFCW to guide designers through the process of adapting VFCW systems to treat domestic wastewater in both dry and rain events. The simplified model makes it possible to link (i) hydraulics, by simulation of ponding time variations, (ii) biological performances, by establishing “dysfunction alerts” based on treatment performance assessment and variations in online N forms effluent from the young VFCW. These “dysfunction alerts” plot the maximal hydraulic load that a filter can accept without compromising its biological activity. The simplified model was used to model long-term hydraulics in the VFCW (i) to analyze the impact of local context and filter design on hydraulic overload acceptance (using “dysfunction alerts” and bypass discharges) and (ii) to propose VFCW designs for accepting hydraulic overload in different contexts. The modelling demonstrates that VFCW can limit days with bypass discharges to less than 20 times per year without jeopardizing filter performances. Moreover, the most problematic scenario on stormwater treatment remains a watershed with high imperviousness coefficient and low slope under a Bretagne-type climate, demonstrating that the filter is more sensitive to periodicity and duration than to intensity of rainfall events.

Les Stations de Traitement des Eaux Usées (STEU) sont l'une des principales sources de rejet de résidus médicamenteux dans l'environnement. Depuis 2009, les Zones de Rejet Végétalisées (ZRV) sont mises en oeuvre entre le rejet de la STEU et le milieu récepteur, mais leurs capacités d'abattement sont encore peu étudiées. Pour combler ce manque, les performances d'épuration de 2 STEU et de leur ZRV, ont été évaluées pendant 2 années. Les résidus médicamenteux (86) ont eu une majorité de rendements d'épuration compris entre 30 et 70 % dans les ZRV et avec des maximums en été et des minimums en hiver. Relativement aux abattements observés sur les STEU en amont, la contribution des ZRV à l'épuration globale du site était inférieure à 30 % du flux entrant. Aussi, la réduction des volumes d'eau rejetés au milieu naturel a été corrélée avec une augmentation des concentrations en résidus médicamenteux. Par ailleurs, les plantes ont montré une capacité d'absorption des médicaments spécifique à l'espèce étudiée, alors que l'observation des concentrations dans les boues, a mis en évidence une tendance à une adsorption en été et un relargage en hiver des micro-polluants. / Wastewater Treatment Plants (WWTP) are considered as one of the most important pharmaceutical compound discharges into the environment. Since 2009, French Water Agencies, promote Surface Flow Treatment Wetlands (SFTWs) at the outlet of WWTPs, between the WWTP and the receiving aquatic environment but their removal efficiencies are not well investigated. To overcome these lacks of knowledge, pollutant removal efficiencies of 2 WWTP and their SFTW were monitoring during 2 years. ln regard to pharmaceutical compounds (86), SFTW removal efficiency rates ranged from 30 to 70% with maximum values in summer and minimum values in winter. The SFTW removal efficiency contributions to WWTP were inferior to 30%. ln addition, SFTW inflow reductions were correlated with an increase of drug compound concentrations in the outflow. Furthermore, there was a specific absorption of these micro pollutants by plants whereas there were dynamic interactions between sampled mud and drugs residues with an adsorption during summer and a release during winter.