Éditeur(s) : HAL CCSD IWA Publishing
Résumé : International audience
The widely occurring degradation product aminomethylphosphonic acid (AMPA) is a result of glyphosate and amino-polyphosphonate degradation. Massive use of the parent compounds leads to the ubiquity of AMPA in the environment, and particularly in water. The purpose of this review is to summarize and discuss current insights into AMPA formation, transport, persistence and toxicity. In agricultural soils, AMPA is concentrated in the topsoil, and degrades slowly in most soils. It can reach shallow groundwater, but rarely managed to enter deep groundwater. AMPA is strongly adsorbed to soil particles and moves with the particles towards the stream in rainfall runoff. In urban areas, AMPA comes from phosphonates and glyphosate in wastewater. It is commonly found at the outlets of Wastewater Treatment Plants (WWTP). Sediments tend to accumulate AMPA, where it may be biodegraded. Airborne AMPA is not negligible, but does wash-out with heavy rainfall. AMPA is reported to be persistent and can be biologically degraded in soils and sediments. Limited photodegradation in waters exists. AMPA mainly has its sources in agricultural leachates, and urban wastewater effluents. The domestic contribution to urban loads is negligible. There is a critical lack of epidemiological data - especially on water exposure - to understand the toxicological effects, if any, of AMPA on humans. Fortunately, well operated water treatment plants remove a significant proportion of the AMPA from water, even though there are not sufficient regulatory limits for metabolites.
ISSN: 0043-1354

hal-01516026
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516026
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516026/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516026/file/Grandcoin%20et%20al.%20-%20AminoMethylPhosphonic%20acid%20%28AMPA%29%20in%20natural%20water.pdf
DOI : 10.1016/j.watres.2017.03.055

Éditeur(s) : HAL CCSD IWA Publishing
Résumé : International audience
UV spectrophotometry is largely used for water and wastewater quality monitoring. The measurement/estimation of specific and aggregate parameters such as nitrate and dissolved organic carbon (DOC) is possible with UV spectra exploitation, from 2 to multi wavelengths calibration. However, if nitrate determination from UV absorbance is known, major optical interferences linked to the presence of suspended solids, colloids or dissolved organic matter limit the relevance of UV measurement for DOC assessment. A new method based on UV spectrophotometric measurement of raw samples (without filtration) coupling a dual pathlength for spectra acquisition and the second derivative exploitation of the signal is proposed in this work. The determination of nitrate concentration is carried out from the second derivative of the absorbance at 226 nm corresponding at the inflexion point of nitrate signal decrease. A short optical pathlength can be used considering the strong absorption of nitrate ion around 210 nm. For DOC concentration determination the second derivative absorbance at 295 nm is proposed after nitrate correction. Organic matter absorbing slightly in the 270-330 nm window, a long optical pathlength must be selected in order to increase the sensitivity. The method was tested on several hundred of samples from small rivers of two agricultural watersheds located in Brittany, France, taken during dry and wet periods. The comparison between the proposed method and the standardised procedures for nitrate and DOC measurement gave a good adjustment for both parameters for ranges of 2-100 mg/L NO3 and 1 30 mg/L DOC. (C) 2016 Elsevier Ltd. All rights reserved.
ISSN: 0043-1354

hal-01460742
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01460742
DOI : 10.1016/j.watres.2016.11.010
PUBMED : 27838025

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Veterinary pharmaceuticals, widely used in intensive livestock production, may contaminate surface waters. Identifying their sources and pathways in watersheds is difficult because i) most veterinary pharmaceuticals are used in human medicine as well and ii) septic or sewer wastewater treatment plants (WWTP) can release pharmaceuticals into surface water, even in agricultural headwater watersheds. This study aimed to analyze the spatiotemporal variability of animal-specific, mixed-use, and human-specific pharmaceuticals, from agricultural headwaters with intensive livestock production and a WWTP to a watershed used for Water Framework Directive monitoring. Grab sampling was performed during one hydrological year upstream and downstream from a WWTP and at three dates in seven nested watersheds with areas of 1.9-84.1km2. Twenty pharmaceuticals were analyzed. Animal-specific pharmaceuticals were detected at all sampling dates upstream and downstream from the WWTP and at concentrations higher than those of human-specific pharmaceuticals. The predominance of animal-specific and mixed-use pharmaceuticals vs. human-specific pharmaceuticals observed at these sampling points was confirmed at the other sampling points. Animal-specific pharmaceuticals were detected mainly during runoff events and periods of manure spreading. A large percentage of mixed-use pharmaceuticals could come from animal sources, but it was difficult to determine. Mixed-use and human-specific pharmaceuticals predominated in the largest watersheds when runoff decreased. In areas of intensive livestock production, mitigation actions should focus on agricultural headwater watersheds to decrease the number of pathways and the transfer volume of veterinary pharmaceuticals, which can be the main contaminants
ISSN: 0048-9697

insu-01574739
https://hal-insu.archives-ouvertes.fr/insu-01574739
DOI : 10.1016/j.scitotenv.2017.07.206
PUBMED : 28783916

Éditeur(s) : Elsevier
Résumé : To improve the knowledge of the survival of enteric viruses in a marine environment, the influence of physico-chemical parameters (temperature, UV, salinity) on the survival of infectious poliovirus 1 and hepatitis A Virus (HAV) in seawater was first studied, the influence of suspended solids (SS) on poliovirus adsorption and survival in seawater was then evaluated and the detection of rotavirus genome in environmental samples (shellfish, river water, treated wastewater) was finally investigated. The results show that temperature has a major impact on virus survival in seawater as the time necessary to inactivate 90 % of the virus (T-90) is 671 days at 4 degrees C and only 25 days at 25 degrees C. Ultraviolet light (42 mW s cm(-2)) rapidly inactivates viruses but HAV is more resistant (T-90 = 2.6 min) than the poliovirus 1 (T-90 = 1.3 min). By contrast, seawater salinity has no effect on virus survival. In presence of SS, 90 % to 99.9 % of the viruses were adsorbed. This adsorption does not provide any protection for viruses with low SS concentrations (3 and 15 mg L-1) but a slight increase in virus survival was observed with a high SS concentration (500 mg L-1). Finally environmental sample analysis indicated that 20 % shellfish, about 40 % river water and 40 % treated wastewater tested positive for the rotavirus genome.
Ce travail a pour but de mieux comprendre le devenir des virus en milieu marin. Dans ce cadre, l'influence de certains paramètres physicochimiques (température, UV et salinité) sur le pouvoir infectieux du poliovirus 1 et du virus de l'hépatite A (VHA) en eau de mer a été évalué, puis l'adsorption du poliovirus 1 sur les matières en suspension (MES) a été étudié, ainsi que les conséquences sur le pouvoir infectieux du virus et enfin le génome des rotavirus a été recherché en milieu naturel (eaux et coquillages). Les résultats montrent que la température est un paramètre important pour la survie des virus puisque le temps nécessaire à inactiver 90 % des virus (T90) en eau de mer est de 671 j à 4 °C alors qu'il est seulement de 25 j à 25 °C. Le rayonnement ultraviolet (42 mW s cm−2) testé en pilote expérimental, permet d'obtenir une inactivation rapide du poliovirus 1 (T90 = 1,3 min). Le VHA est plus résistant avec un T90 = 2,6 min. En revanche la salinité de l'eau de mer n'a pas d'influence sur la survie des virus. En ce qui concerne l'influence des MES, les résultats montrent qu'en présence de 3, 15 et 500 mg L−1 de Na-montmorillonite la majorité des virus est adsorbée (90 à 99,9 %). Cet état adsorbé ne procure aucune protection aux virus pour les faibles concentrations de MES (3 et 15 mg L−1) alors qu'une augmentation significative de survie est observée pour les fortes concentrations (500 mg L−1). Enfin, l'analyse d'échantillon de l'environnement a montré que 20 % des fruits de mer, environ 40 % des eaux de rivière et environ 40 % des eaux usées traitées testées contenaient du génome de rotavirus.
Oceanologica Acta (0399-1784) (Elsevier), 1998-11 , Vol. 21 , N. 6 , P. 983-992

Droits : 1998 Ifremer / CNRS / IRD - Published by Elsevier SAS
http://archimer.ifremer.fr/doc/1998/publication-846.pdf
DOI:10.1016/S0399-1784(99)80020-6
http://archimer.ifremer.fr/doc/00000/846/

Éditeur(s) : HAL CCSD Frontiers Media
Résumé : International audience
The early 2000s marked the end of the Golden age of the antibiotics and the beginning of the awareness on the potential threat to human health due to the dissemination of antimicrobial resistance. As a base-line study, we investigated the antimicrobial susceptibility of 99 strains of non-O1/non-O139 Vibrio cholerae isolated fromwastewater and shellfish in 2000/2001 within La Rance estuary (Brittany, France). All isolates were susceptible to amoxicillin-clavulanic acid, cefotaxime, imipenem, chloramphenicol, nalidixic acid, ciprofloxacin, norfloxacin, amikacin, gentamicin, tetracycline, doxycycline, trimethoprim-sulfamethoxazole, and erythromycin. The only resistances were to streptomycin, sulfonamides and ampicillin: 54.6% of the isolates had acquired resistance to at least one antimicrobial agent among them and only six isolates from cockles were multidrug resistant. On the basis of the distribution of a limited selection of resistance associated genes, our study shows that V. cholerae can constitute an environmental reservoir for these genes. However, none of our isolates harbored integron. This result casts doubt on the capacity of non-O1/non-O139 V. cholerae to acquire resistance-associated genes in such context, and on its potential role of indicator of the dissemination of antimicrobial resistance in the aquatic environment.
ISSN: 1664-302X

hal-01616065
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616065
DOI : 10.3389/fmicb.2017.01637
PUBMED : 28955305

Résumé : Les biofilms électroactifs (EA) sont des consortia bactériens mono ou pluri-espèces, qui ont la faculté d’échanger des électrons provenant de leur métabolisme avec les surfaces solides conductrices des électrodes. Cette découverte est à l’origine d’un nouveau dispositif énergétique : la pile à combustible microbienne (PACM). Depuis les années 2000, la littérature scientifique sur les biofilms EA et sur les PACM explose, notamment grâce à la découverte de bactéries capables de transférer par voie directe – par des pili ou protéines transmembranaires – des électrons vers les électrodes. Plusieurs sources de bactéries EA ont été à ce jour découvertes, allant de cultures pures à des communautés bactériennes plus complexes. Ces dernières sont issues de milieux aqueux naturels (milieux marins ou d’eau douce), industriels ou urbains (effluents d’industrie, eaux usées domestiques). La plupart de ces sources bactériennes proviennent d’environnements de climat tempéré. Dans ce travail de thèse, plusieurs sols de milieux humides de la Guyane ont été identifiés comme étant de sources de bactéries EA. Les expériences menées sous potentiel d’électrode imposé et constant ont permis d’étudier l’adhésion à la surface d’électrode des biofilms EA issus de la flore endogène des milieux sélectionnés. La formation de bioanodes et de biocathodes a été possible en présence respectivement d’acétate et d’oxygène dans les milieux. Une étude par voltammétrie cyclique a mis en évidence les pics d’oxydo-réduction en lien avec les échanges électroniques du biofilm EA et de l’électrode. En optimisant la procédure de formation des biofilms EA par chronoampérométrie (surface d’électrode plus importante, apport en continu et progressif du substrat), une densité de courant maximale de 12 A/m2 et un rendement faradique de 24 % ont été obtenus. Une autre méthode pour former des biofilms EA à partir d’un milieu choisi, la mangrove, a consisté à utiliser deux prototypes de PACM : une pile à compartiment unique et à cathode à air, et une pile benthique. Dans les deux cas, les biofilms EA ont pu être formés et étudiés, complétant certaines observations faites sous potentiel imposé. La PACM benthique s’est avérée être la plus proche d’une application à grande échelle puisqu’elle a été complètement autonome : anode et cathode utilisant uniquement le milieu pour fonctionner. Elle a pu être étudiée en laboratoire comme sur le terrain.
Electroactive biofilms (EA) are mono or multi-species bacterial consortia, which have the ability to exchange electrons from their metabolism with solid surfaces of conductive electrodes. This discovery is the basis for a device of energy production: microbial fuel cell (MFC). Since the 2000s, the scientific literature on EA biofilms and MFC explodes, thanks to the discovery of bacteria that are able to transfer directly – by pili or trans-membrane proteins – electrons to electrodes. Several sources of EA bacteria were discovered to date, ranging from pure cultures to more complex bacterial communities. Those last are from natural (marine and freshwater), industrial or urban (industrial effluents, domestic wastewater) aqueous environments. However, the vast majority of these are from temperate environments.In this thesis, several wetland soils of French Guiana have been identified as sources of EA bacteria. Experiments under poised and constant electrode potential were used to examine adherence to the electrode surface of EA biofilms from the endogenous flora of selected environments. Formation of bioanodes and biocathodes was possible in the presence respectively of acetate and oxygen in the media. A study by cyclic voltammetry showed the redox peaks related to electronic exchanges between EA biofilm and electrode. By optimizing the process of EA biofilm formation by chronoamperometry (larger electrode surface, providing continuous and progressive substrate), a maximum current density of 12 A/m2 and a coulombic efficiency of 24% were obtained.Another method to form EA biofilms from a chosen medium (mangrove) was to use two MFC prototypes: a single compartment and air cathode one, and a benthic one. In both cases, the EA biofilms have been trained and studied supplementing certain observations made under poised polarization. MFC benthic proved to be the closest to a wide application since it was completely autonomous, anode and cathode only using the medium to function. It has been studied in the laboratory and in the field.

http://www.theses.fr/2012AGUY0560/document