Background, aim, and scope The present study focuses on the temporal concentration changes of four common organic pollutants in small freshwater streams of Hesse, Germany. The substances (tris(2-chloroethyl)phosphate (TCEP), the technical isomer mixture of 4-nonylphenol (NP), 2-(t-butylamino)-4-(ethylamino)-6-(methylthio)-s-triazine (terbutryn), and N,N-diethyl-m-toluamide (DEET)) are subject to differing regulations. Whereas the use of NP and the related nonylphenolethoxylates (NPEOs) are almost completely banned under EU directive 2003/53/EC, the herbicide terbutryn is only restricted for use as a herbicide in the majority of member states of the European Union (EU). In contrast, TCEP and DEET are not regulated by legislation, but have been replaced in some products through consumer pressure. The impact of regulation on the environmental concentrations of these pollutants is discussed. Materials and methods The substances were monitored in small freshwater streams in the Hessisches Ried region, Germany, during the period September 2003 to September 2006. The samples were extracted with solid phase extraction (SPE) and analyzed by coupled gas chromatography-mass spectrometry (GC-MS). Results All target compounds were detected frequently within the fresh water streams of the study area. Monitoring in the study area revealed a significant concentration decrease only for NP. For the other three compounds, no significant concentration decrease was observed. Terbutryn concentrations and loads showed a seasonal trend with higher levels in summer and autumn, but were also present in winter and spring. Concentrations of TCEP and DEET were in the range of prior investigations. Discussion The decrease of NP concentrations and loads during the sampling period indicates that the regulation of NP and NP ethoxylates has led to a significant improvement in reducing the occurrence of this compound in the aquatic environment. Furthermore, the ban on agricultural use of terbutryn at the end of 2003 had no discernable influence on terbutryn concentrations in the following years. Conclusions The benefits of national bans or self-regulations by manufacturers on several chemicals appear to be limited. In contrast, the European-wide ban (of NP) revealed to be effective in preventing the substance from entering the aquatic environment on a large scale and reduced the NP concentration to an acceptable level (i.e., below the PNEC). Recommendations and perspectives Further research is needed to investigate diffuse sources and point sources of terbutryn not related to agriculture. Further research is required to find an explanation for the ongoing high concentration of TCEP in river water despite of the supposed replacement of TCEP by TCPP already in the 1990s.

Background, aim, and scope Improving the parameterization of processes in the atmospheric boundary layer (ABL) and surface layer, in air quality and chemical transport models. To do so, an asymmetrical, convective, non-local scheme, with varying upward mixing rates is combined with the non-local, turbulent, kinetic energy scheme for vertical diffusion (COM). For designing it, a function depending on the dimensionless height to the power four in the ABL is suggested, which is empirically derived. Also, we suggested a new method for calculating the in-canopy resistance for dry deposition over a vegetated surface. Materials and methods The upward mixing rate forming the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. The vertical eddy diffusivity is parameterized using the mean turbulent velocity scale that is obtained by the vertical integration within the ABL. In-canopy resistance is calculated by integration of inverse turbulent transfer coefficient inside the canopy from the effective ground roughness length to the canopy source height and, further, from its the canopy height. Results This combination of schemes provides a less rapid mass transport out of surface layer into other layers, during convective and non-convective periods, than other local and non-local schemes parameterizing mixing processes in the ABL. The suggested method for calculating the in-canopy resistance for calculating the dry deposition over a vegetated surface differs remarkably from the commonly used one, particularly over forest vegetation. Discussion In this paper, we studied the performance of a non-local, turbulent, kinetic energy scheme for vertical diffusion combined with a non-local, convective mixing scheme with varying upward mixing in the atmospheric boundary layer (COM) and its impact on the concentration of pollutants calculated with chemical and air-quality models. In addition, this scheme was also compared with a commonly used, local, eddy-diffusivity scheme. Simulated concentrations of NO₂ by the COM scheme and new parameterization of the in-canopy resistance are closer to the observations when compared to those obtained from using the local eddy-diffusivity scheme. Conclusions Concentrations calculated with the COM scheme and new parameterization of in-canopy resistance, are in general higher and closer to the observations than those obtained by the local, eddy-diffusivity scheme (on the order of 15-22%). Recommendations and perspectives To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO₂) were compared for the years 1999 and 2002. The comparison was made for the entire domain used in simulations performed by the chemical European Monitoring and Evaluation Program Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

National audience | Given the good performance of geosynthetic material for drainage, it seems interesting to use these products to replace part or all of the drainage layer commonly used in landfill cells (silicate materials). The calculation showed that the replacement of a granular layer of 0.50 m by a drainage geosynthetic product is not always as easy as it seems: the maximum water head legally acceptable decreases with the thickness of the studied equivalent solution, which limits its ability to flow. ARCADIS and SITA DECTRA present here a case study on the Romagne-sous-Montfaucon landfill site for which a hybrid (solid granular + geosynthetic) was called. | Compte tenu des bonnes performances des géosynthétiques de drainage, il semble intéressant d'utiliser ces produits pour remplacer tout ou partie du massif drainant généralement utilisé en fond de casier d'installations de stockage de déchets. Le calcul montre que le remplacement d'une couche granulaire de 0,50 m par un géosynthétique de drainage n'est pas toujours aussi aisé qu'il y paraît : la charge maximale réglementairement acceptable diminue avec l'épaisseur du dispositif équivalent considéré, ce qui limite sa capacité de débit. Arcadis et Sita Dectra présentent ici une étude de cas sur le site de Romagne-sous-Montfaucon pour lequel un dispositif hybride (massif granulaire + géosynthétique) a été préconisé.

[Departement_IRSTEA]Eaux [TR1_IRSTEA]RIVAGE | National audience | The paper presents parts of the recent guide of recommendations "Mountain reservoirs". It makes a synthesis of a feedback on the behaviour and the pathology of geomembrane lining systems and gives the strong recommendations of the guide relative to these systems, in particular onto the structure support, the drainage inherent to the DEG and the covering structure. A general description of the guide ends the article. | L'article présente, à travers le récent guide de recommandations « Retenues d'altitude », la synthèse d'un retour d'expérience sur le comportement et la pathologie des dispositifs d'étanchéité par géomembrane (DEG) en altitude. Il donne les recommandations fortes du guide relatives à ces dispositifs, en particulier sur la structure support, le drainage inhérent au DEG et la structure de recouvrement. Un descriptif général du guide termine l'article.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-SOWASTE | National audience | Protecting geotextiles are used in the design of watertight bottom liners at landfill sites, above the géomembrane, to protect it against puncture during the installation of the drainage layer and, during the service life, to the weight of the waste to be put in place. To date, the results of the 2 standard tests (static and dynamic tests) given by the technical sheets for the protecting geotextiles are not sufficient to choose the good geotextile. The development of an experimental procedure to simulate in the lab the waste loading conditions is presented here; this procedure uses large size static damage tests and follows a previous study concerning the implementation dynamic conditions (Budka & al., 2006). | Les géotextiles sont utilisés dans la constitution des étanchéités des installations de stockage de déchets (ISD) pour protéger la géomembrane contre les effets du poinçonnement liés à la mise en ½uvre de la couche de drainage puis, en service, au poids des déchets sus jacents. À ce jour, les deux essais normalisés de poinçonnement, statique et dynamique, figurant sur les fiches techniques des géotextiles de protection ne permettent pas directement le choix du produit adapté. La mise au point d'une procédure d'étude des effets des sollicitations en service est présentée ici ; elle s'appuie sur des essais d'endommagement de grandes dimensions et fait suite à une étude déjà publiée sur l'effet des sollicitations de mise en ½uvre (Budka et al., 2006).

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-SOWASTE | National audience | The objective of the Equivalence Guide is to define rules of good practice with respect to equivalent solutions for landfill mineral barriers. The guide refers primarily to non-hazardous waste landfills. The guide, which was first drafted in 2002, was updated in 2008, by a working group composed of the main organisations working on landfill mineral barriers in France. The update also benefited from feedback from professional partners (consultants, landfill operators, geosynthetic suppliers...). This paper summarizes the main changes with respect to the previous version. | Le « Guide Équivalence » a pour objectif de définir des règles de bonne pratique en matière de recherche de solutions « équivalentes » en étanchéité passive d'installation de stockage de déchets. Les principaux sites concernés par ce guide sont les installations de stockage de déchets non dangereux (ISDND). Ce guide, dont la première version date de 2002, a été réactualisé par un groupe de travail constitué des principaux organismes intervenant sur la thématique des barrières minérales d'ISD en France. Cette réactualisation a également bénéficié d'un retour d'expérience recueilli auprès de la profession (bureaux d'étude, exploitants, fournisseurs de géosynthétiques ). Cet article fait une synthèse des principales modifications par rapport à la version antérieure.

Production of methane and carbon dioxide as well as methane concentrations in surface waters and emissions to the atmosphere were investigated in two flow-through lake complexes (Uzlina-Isac and Puiu-Rosu-Rosulet) in the Danube Delta during post-flood conditions in May and low water level in September 2006. Retained nutrients fuelled primary production and remineralisation of bioavailable organic matter. This led to an observable net release of methane, particularly in the lakes Uzlina, Puiu and Rosu in May. Input from the Danube River, from redbuds and benthic release contributed to CH₄ concentrations in surface waters. In addition to significant river input of CO₂, this trace gas was released via aerobic remineralisation within the water column and in top sediments. Emission patterns of CO₂ widely overlapped with those of CH₄. Generally, greenhouse gas emissions peaked in the lake complex adjacent to the Danube River in May due to strong winds and decreased with increasing hydrological distance from the Danube River. Intense remineralisation of organic matter in the Danube Delta lakes results in a net source of atmospheric greenhouse gases.

Background, aim, and scope Pharmaceuticals and their metabolites are detected in the aquatic environment and our drinking water supplies. The need for high quality drinking water is one of the most challenging problems of our times, but still only little knowledge exists on the impact of these compounds on ecosystems, animals, and man. Biological waste water treatment in constructed wetlands is an effective and low-cost alternative, especially for the treatment of non-industrial, municipal waste water. In this situation, plants get in contact with pharmaceutical compounds and have to tackle their detoxification. The mechanisms for the detoxification of xenobiotics in plants are closely related to the mammalian system. An activation reaction (phase I) is followed by a conjugation (phase II) with hydrophilic molecules like glutathione or glucose. Phase III reactions can be summarized as storage, degradation, and transport of the xenobiotic conjugate. Until now, there is no information available on the fate of pharmaceuticals in plants. In this study, we want to investigate the fate and metabolism of N-acetyl-4-aminophenol (paracetamol) in plant tissues using the cell culture of Armoracia rusticana L. as a model system. Materials and methods A hairy root culture of A. rusticana was treated with acetaminophen in a liquid culture. The formation and identification of metabolites over time were analyzed using HPLC-DAD and LC-MSn techniques. Results With LC-MS technique, we were able to detect paracetamol and identify three of its metabolites in root cells of A. rusticana. Six hours after incubation with 1 mM of acetaminophen, the distribution of acetaminophen and related metabolites in the cells resulted in 18% paracetamol, 64% paracetamol-glucoside, 17% paracetamol glutathione, and 1% of the corresponding cysteine conjugate. Discussion The formation of two independently formed metabolites in plant root cells again revealed strong similarities between plant and mammalian detoxification systems. The detoxification mechanism of glucuronization in mammals is mirrored by glucosidation of xenobiotics in plants. Furthermore, in both systems, a glutathione conjugate is formed. Due to the existence of P450 enzymes in plants, the formation of the highly reactive NAPQI intermediate is possible. Conclusions In this study, we introduce the hairy root cell culture of A. rusticana L. as a suitable model system to study the fate of acetaminophen in plant tissues. Our first results point to the direction of plants being able to take up and detoxify the model substrate paracetamol. These first findings underline the great potential of using plants for waste water treatments in constructed wetlands. Recommendations and perspectives This very first study on the detoxification of a widely used antipyretic agent in plant tissues again shows the flexibility of plant detoxification systems and their potential in waste water treatment facilities. This study covers only the very first steps of acetaminophen detoxification in plants; still, there is no data on long-term exposure as well as the possible impact of pharmaceuticals on the plant health and stress defense. Long-term experiments need to be performed to follow the fate of acetaminophen in root and leaf cells in a whole plant system, and to evaluate possible usage of plants for the remediation of acetaminophen from waste water.

Background, aim, and scope Pharmaceuticals and personal care products (PPCPs) including antibiotics, endocrine-disrupting chemicals, and veterinary pharmaceuticals are emerging pollutants, and their environmental risk was not emphasized until a decade ago. These compounds have been reported to cause adverse impacts on wildlife and human. However, compared to the studies on hydrophobic organic contaminants (HOCs) whose sorption characteristics is reviewed in Part IV of this review series, information on PPCPs is very limited. Thus, a summary of recent research progress on PPCP sorption in soils or sediments is necessary to clarify research requirements and directions. Main features We reviewed the research progress on PPCP sorption in soils or sediments highlighting PPCP sorption different from that of HOCs. Special function of humic substances (HSs) on PPCP behavior is summarized according to several features of PPCP-soil or sediment interaction. In addition, we discussed the behavior of xenobiotic chemicals in a three-phase system (dissolved organic matter (DOM)-mineral-water). The complexity of three-phase systems was also discussed. Results Nonideal sorption of PPCPs in soils or sediments is generally reported, and PPCP sorption behavior is relatively a more complicated process compared to HOC sorption, such as the contribution of inorganic fractions, fast degradation and metabolite sorption, and species-specific sorption mechanism. Thus, mechanistic studies are urgently needed for a better understanding of their environmental risk and for pollution control. Discussion Recent research progress on nonideal sorption has not been incorporated into fate modeling of xenobiotic chemicals. A major reason is the complexity of the three-phase system. First of all, lack of knowledge in describing DOM fractionation after adsorption by mineral particles is one of the major restrictions for an accurate prediction of xenobiotic chemical behavior in the presence of DOM. Secondly, no explicit mathematical relationship between HS chemical-physical properties, and their sorption characteristics has been proposed. Last but not least, nonlinear interactions could exponentially increase the complexity and uncertainties of environmental fate models for xenobiotics. Discussion on proper simplification of fate modeling in the framework of nonlinear interactions is still unavailable. Conclusions Although the methodologies and concepts for studying HOC environmental fate could be adopted for PPCP study, their differences should be highly understood. Prediction of PPCP environmental behavior needs to combine contributions from various fractions of soils or sediments and the sorption of their metabolites and different species. Recommendations and perspectives More detailed studies on PPCP sorption in separated soil or sediment fractions are needed in order to propose a model predicting PPCP sorption in soils or sediments based on soil or sediment properties. The information on sorption of PPCP metabolites and species and the competition between them is still not enough to be incorporated into any predictive models.