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结果 1671-1680 的 4,033
Biocompatible poly(vinyl alcohol) nanoparticle-based binary blends for oil spill control
2016
Fouad, Rasha Refaat | Aljohani, Hind Abdullah | Shoueir, Kamel Rizq
In the current study, biocompatible and biodegradable blends based on poly(vinyl alcohol) nanoparticles – PVAn mixed with either chitosan (Ch) or starch (St) – were prepared and investigated as nanoabsorbents for oil elimination from wastewater. The use of water/dimethyl sulfoxide (DMSO) as a mixed solvent is the key factor for preparing aggregated PVAn, which is further mixed with Ch or St. Nanoblends were applied as oil absorbents, and the results showed that PVAn/St possess high adsorption capacity than PVAn/Ch and PVAn. The maximum sorption capacities (qg/g) of the PVAn/Ch sorbents for hydraulic oil, kerosene, and toluene were 33.6, 73.96, and 93.1g/g, respectively. The absorbed oil could be rapidly recovered by simple mechanical squeezing and reused without any other modification. The blends showed excellent reusability and could be reused for at least 10 times with minimal losses. The current study demonstrates the application of these blends as an ideal alternative sorbent for oil spillage cleanup.
显示更多 [+] 显示较少 [-]Urban dew formation efficiency and chemistry in Poland
2016
Gałek, G. | Sobik, M. | Błaś, M. | Polkowska, Ż | Cichała-Kamrowska, K.
The measurements of dew formation efficiency and chemistry were performed in Poland in September 2009, as a part of a longer, two-year sampling campaign. Pairs of sites, representing centers of major Polish cities and rural conditions in three different regions, were compared. With the aim to get more detailed landuse-oriented characteristics of dew, two additional sites were set close to Wroclaw. Collection of dew at each site was made by means of flat, insulated, passive radiative condenser, 1 m2 in area. The analysis has included a number of physico-chemical variables, i.e.: dew water volume, pH, conductivity (σ), concentration of some major anions: F−, Cl−, NO2−, NO3−, SO42−, PO43− and cations: Na+, K+, Mg2+, Ca2+, NH4+. The dew formation efficiency at the rural stations is about two times higher than in the nearby city centres and such regularity is complex in its origin. The results show generally low contamination of dew (16.8–132.6 μS cm−1) in comparison to literature examples, but definitely more acidic (pH ∼5.0). The urban dew is characterized about two times higher contamination than nearby rural and independently of the place of collection the dominant ions are NO3−, SO42− and Ca2+, all anthropogenic in origin. The sources of dew pollution have mostly regional character or alternatively urban emissions effectively contaminate dew even several tens of kilometers away. The urban dew pH is higher than rural, but dew is potentially acidic and corrosive at the level of urban canopy.
显示更多 [+] 显示较少 [-]From Fields to Rivers: Chlordecone Transfer in Water | Des parcelles aux cours d'eau : transferts de chlordécone dans les eaux
2016
Mottes, Charles | Charlier, Jean-Baptiste | Rocle, Nicolas | Gresser, J. | Lesueur Jannoyer, M. | Cattan, P. | Lesueur Jannoyer, M. | Cattan, P. | Woignier, Thierry | Clostre, Florence | Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad) | Environnement, territoires et infrastructures (UR ETBX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Office de l'Eau Martinique | Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE) ; Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS)
[Departement_IRSTEA]Territoires [TR1_IRSTEA]DTAM | International audience | The book deals with a long term pollution problem, generated by the former use of organochlorine pesticides. Through a case study of the chlordecone pollution in the French West Indies, the authors illustrate a global and systemic mobilization of research institutions and public services. This "management model", together with its major results, the approach and lessons to be learned, could be useful to other situations. This book gathers all the works that have been carried out over the last ten years or more and links them to decision makers’ actions and stakeholders’ expectations. This reference fills a gap in the literature on chronic pollution.
显示更多 [+] 显示较少 [-]Microplastiques dans différents compartiments du cycle urbain de l’eau
2016
Dris, Rachid | Gasperi, Johnny | Rocher, Vincent | Tassin, Bruno | Laboratoire Eau Environnement et Systèmes Urbains (LEESU) ; AgroParisTech-École nationale des ponts et chaussées (ENPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12) | SIAAP - Direction du Développement et de la Prospective ; Syndicat interdépartemental pour l'assainissement de l'agglomération parisienne (SIAAP)
International audience
显示更多 [+] 显示较少 [-]Physiological responses of the hybrid larch (Larix x eurolepis Henry) to cadmium exposure and distribution of cadmium in plantlets
2016
Bonet, Amandine | Lelu-Walter, Marie-Anne | Faugeron, Céline | Gloaguen, Vincent | Saladin, Gaëlle | Laboratoire de Chimie des Substances Naturelles (LCSN) ; Université de Limoges (UNILIM)-Génomique, Environnement, Immunité, Santé, Thérapeutique (GEIST FR CNRS 3503) | Unité de recherche Amélioration, Génétique et Physiologie Forestières (AGPF) ; Institut National de la Recherche Agronomique (INRA)
International audience | Phytoextraction of Cd is a growing biotechnology although we currently know few Cd-hyperaccumulators, i.e. plant species able to accumulate at least 0.1 mg Cd g-1 dry weight in aerial organs. Owing their deep root system and high biomass, trees are more and more preferred to herbaceous species for phytoextraction. Assuming that conifers could be relevant models under cold climates, we investigated cadmium tolerance of the hybrid larch Larix × eurolepis Henry (L. decidua × L. kaempferi) and the efficiency of this species to store this metal. In vitro grown larches were chosen in order to reduce time of exposure and to more rapidly evaluate their potential efficiency to accumulate Cd. One-month-old plantlets were exposed for 2 and 4 weeks to 250 and 500 µM Cd. Results showed that they tolerated a four-week exposure to 250 µM Cd whereas the content of photosynthetic pigment strongly dropped in plantlets growing in presence of 500 µM Cd. In presence of 250 µM Cd, shoot growth slightly decreased but photosynthetic pigment and total soluble carbohydrate contents were not modified and no lipid peroxidation was detected. In addition, these plantlets accumulated proline, particularly in shoots (2 - 3 times more than control). In roots, Cd concentration in the intracellular fraction was always higher than in the cell wall fraction contrary to shoots where Cd concentration in the cell wall fraction increased with time and Cd concentration in the medium. In shoots, Cd concentration was lower than in roots with a ratio of 0.2 after 4 weeks of exposure but stayed around 0.2 mg g-1 dry weight, thus a value higher than the threshold requested for Cd-hyperaccumulators. Hybrid larch would thus be a relevant candidate for field test of Cd-phytoextraction.
显示更多 [+] 显示较少 [-]Multivariate spatial analyses of the distribution and origin of trace and major elements in soils surrounding a secondary lead smelter
2016
Schneider, Arnaud R. | Morvan, Xavier | Saby, Nicolas P.A. | Cancès, Benjamin | Ponthieu, Marie | Gommeaux, Maxime | Marin, Béatrice | Groupe d'Étude sur les Géomatériaux et Environnements Naturels, Anthropiques et Archéologiques - EA 3795 (GEGENAA) ; Université de Reims Champagne-Ardenne (URCA)-SFR Condorcet ; Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-Université de Reims Champagne-Ardenne (URCA)-Centre National de la Recherche Scientifique (CNRS)-Maison des Sciences Humaines de Champagne-Ardenne (MSH-URCA) ; Université de Reims Champagne-Ardenne (URCA)-Université de Reims Champagne-Ardenne (URCA) | InfoSol (InfoSol) ; Institut National de la Recherche Agronomique (INRA)
International audience | Major and trace elements in soils originate from natural processes and different anthropogenic activities which are difficult to discriminate. On a 17-ha impacted site in northern France, two industrial sources of soil contamination were xidentified: a former iron foundry and a current secondary lead smelter. To discriminate and map natural and anthropogenic sources of major and trace elements on this site, the rarely applied MULTISPATI-principal component analysis (PCA) method was used. Using a 20-m x 20-m grid, 247 topsoil horizons were sampled and analysed with a field-portable X-ray fluorescence analyser for screening soil contamination. The study site was heavily contaminated with Pb and, to a lesser degree, with Sn. Summary statistics and enrichment factors allowed the differentiation of the main lithogenic or anthropogenic origin of the elements. The MULTISPATI-PCA method, which explained 73.9% of the variability with the three first factors, evidenced strong spatial structures. Those spatial structures were attributed to different natural and artificial processes in the study area. The first axis can be interpreted as a lithogenic effect. Axes 2 and 3 reflect the two different contamination sources. Pb, Sn and S originated from the secondary lead smelter while Fe and Ca were mainly derived from the old iron foundry activity and the old railway built with foundry sand. This study demonstrated that the MULTISPATI-PCA method can be successfully used to investigate multicontaminated sites to discriminate the various sources of contamination.
显示更多 [+] 显示较少 [-]Plastiques et dérivés : quels impacts écotoxicologiques sur les écosystèmes terrestres ?
2016
Mougin, Christian | Lamy, Isabelle
Plastiques et dérivés : quels impacts écotoxicologiques sur les écosystèmes terrestres ? . Colloque ARET 2016 : Plastiques : quels enjeux pour demain ? Pollution physico-chimique & Impacts environnementaux et sanitaires. Ecoparc Rovaltain
显示更多 [+] 显示较少 [-]Transfer of Chlordecone from the Environment to Animal-Derived Products
2016
Jurjanz, Stéfan | Jondreville, Catherine | Fournier, Agnès | Lerch, Sylvain | Rychen, Guido | Feidt, Cyril | Unité de Recherches Animal et Fonctionnalités des Produits Animaux (URAFPA) ; Institut National de la Recherche Agronomique (INRA)-Université de Lorraine (UL) | Magalie Lesueur Jannoyer | Philippe Cattan | Thierry Woignier | Florence Clostre
International audience
显示更多 [+] 显示较少 [-]Evaluating exposure of pedestrians to airborne contaminants associated with non-potable water use for pavement cleaning
2016
Seidl, Martin | Da, Guillaume | Ausset, Patrick | Haenn, S. | Géhin, Evelyne | Moulin, Laurent | Laboratoire Eau Environnement et Systèmes Urbains (LEESU) ; AgroParisTech-École nationale des ponts et chaussées (ENPC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12) | Centre d'Etudes et Recherches en Thermique, Environnement et Systèmes [Créteil] (CERTES EA 3481) ; Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12) | Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS) | Eau de Paris, DQDRE ; Eau de Paris | This study was conducted in the framework of the French research program OPUR 4 (Observatoire des polluantsurbains) and supported by the research consortium OSU EFLUVE (Observatoire des sciences de l’universEnveloppesfluides: de la ville à l’exobiologie).
International audience | Climate change and increasing demography press local authorities to look after affordable water resources and replacement of drinking water for city necessities like street and pavement cleaning by more available raw water. Though, the substitution of drinking by non-drinking resources demands the evaluation of sanitary hazards. This article aims therefore to evaluate the contribution of cleaning water to the overall exposure of city dwellers in case of wet pavement cleaning using crossed physical, chemical and biological approaches. The result of tracer experiments with fluorescein show that liquid water content of the cleaning aerosol produced is about 0.24 g m(-3), rending possible a fast estimation of exposure levels. In situ analysis of the aerosol particles indicates a significant increase in particle number concentration and particle diameter, though without change in particle composition. The conventional bacterial analysis using total coliforms as tracer suggests that an important part of the contamination is issued from the pavement. The qPCR results show a more than 20-fold increase of background genome concentration for Escherichia coli and 10-fold increase for Enterococcus but a negligible contribution of the cleaning water. The fluorescence analysis of the cleaning aerosol confirms the above findings identifying pavement surface as the major contributor to aerosol organic load. The physical, chemical and microbiological approaches used make it possible to describe accurately the cleaning bioaerosol and to identify the existence of significantly higher levels of all parameters studied during the wet pavement cleaning. Though, the low level of contamination and the very short time of passage of pedestrian in the zone do not suggest a significant risk for the city dwellers. As the cleaning workers remain much longer in the impacted area, more attention should be paid to their chronic exposure.
显示更多 [+] 显示较少 [-]Effects of an environmentally relevant concentration of diuron on oyster genitors during gametogenesis: responses of early molecular and cellular markers and physiological impacts
2016
Akcha, Farida | Barranger, Audrey | Bachere, Evelyne | Berthelin, C. Heude | Piquemal, D. | Alonso, P. | Sallan, R. Rondon | Dimastrogiovanni, G. | Porte, C. | Menard, Dominique | Szczybelski, A. | Benabdelmouna, Abdellah | Auffret, M. | Rouxel, Julien | Burgeot, Thierry
Genitors of the Pacific oyster Crassostrea gigas were submitted during gametogenesis to a short pulse exposure to the herbicide diuron at a realistic environmental concentration. Histological analysis showed no effect of diuron on gametogenesis course, sex ratio and reproductive effort. A non-significant increase in testosterone and progesterone levels was observed in genitors exposed to the herbicide. At cell level, diuron exposure was shown to modulate the phagocytic activity of circulating hemocytes. The results of a transcriptional analysis showed that diuron affected the expression of genes belonging to functions known to play a major role during oyster gametogenesis such as gene transcription regulation, DNA replication and repair, DNA methylation and cytokinesis. Taking into account the results we previously obtained on the same genitors, this study showed a negative effect of diuron on oyster reproduction by inducing both structural and functional modifications of the DNA.
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