خيارات البحث
النتائج 111 - 120 من 3,991
Phthalate pollution in an Amazonian rainforest
2016
Lenoir, Alain | Boulay, Raphaël | Dejean, Alain | Axel, Touchard | Cuvillier-Hot, Virginie | Institut de recherche sur la biologie de l'insecte (IRBI) ; Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire Ecologie Fonctionnelle et Environnement (LEFE) ; Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT) | Ecologie des forêts de Guyane (UMR ECOFOG) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-AgroParisTech-Université de Guyane (UG)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA) | Évolution, Écologie et Paléontologie (Evo-Eco-Paleo) - UMR 8198 (Evo-Eco-Paléo (EEP)) ; Université de Lille-Centre National de la Recherche Scientifique (CNRS) | CNRS : Centre d'Etudes de la Biodiversite Amazonienne (CEBA)
International audience | Phthalates are ubiquitous contaminants and endocrine-disrupting chemicals that can become trapped in the cuticles of insects, including ants which were recognized as good bioindicators for such pollution. Because phthalates have been noted in developed countries and because they also have been found in the Arctic, a region isolated from direct anthropogenic influence, we hypothesized that they are widespread. So, we looked for their presence on the cuticle of ants gathered from isolated areas of the Amazonian rainforest and along an anthropogenic gradient of pollution (rainforest vs. road sides vs. cities in French Guiana). Phthalate pollution (mainly di(2-ethylhexyl) phthalate (DEHP)) was higher on ants gathered in cities and along road sides than on those collected in the pristine rainforest, indicating that it follows a human-mediated gradient of disturbance related to the use of plastics and many other products that contain phthalates in urban zones. Their presence varied with the ant species; the cuticle of Solenopsis saevissima traps higher amount of phthalates than that of compared species. However, the presence of phthalates in isolated areas of pristine rainforests suggests that they are associated both with atmospheric particles and in gaseous form and are transported over long distances by wind, resulting in a worldwide diffusion. These findings suggest that there is no such thing as a "pristine" zone.
اظهر المزيد [+] اقل [-]Alternative dry separation of PM10 from soils for characterization by kinetic extraction: example of new Caledonian mining soils
2016
Pasquet, Camille | Gunkel-Grillon, Peggy | Laporte-Magoni, Christine | Serres, Arnaud | Quiniou, Thomas | Rocca, François | Monna, Fabrice | Losno, Remi | van Oort, Folkert | Chateau, Carmela | Université de la Nouvelle-Calédonie (UNC) | Archéologie, Terre, Histoire, Sociétés [Dijon] (ARTeHiS) ; Ministère de la Culture et de la Communication (MCC)-Université de Bourgogne (UB)-Centre National de la Recherche Scientifique (CNRS) | Institut de Physique du Globe de Paris (IPGP) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS) | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | UFR SVTE ; Université Bourgogne Franche-Comté [COMUE] (UBFC)
A simple new device for dry separation of fine particulate matter from bulk soil samples is presented here. It consists of a stainless steel tube along which a nitrogen flow is imposed, resulting in the displacement of particles. Taking into account particle transport, fluid mechanics, and soil sample composition, a tube 6-m long, with a 0.04-m diameter, was found best adapted for PM10 separation. The device rapidly produced several milligrams of particulate matter, on which chemical extractions with EDTA were subsequently performed to study the kinetic parameters of extractable metals. New Caledonian mining soils were chosen here, as a case-study. Although the easily extracted metal pool represents only 0.5–6.4 % of the total metal content for the elements studied (Ni, Co, Mn), the total concentrations are extremely high. This pool is therefore far from negligible, and can be troublesome in the environment. This dry technique for fine particle separation from bulk parent soil eliminates the metal-leaching risks inherent in wet filtration and should therefore ensure safe assessment of environmental quality in fine-textured, metal-contaminated soils.
اظهر المزيد [+] اقل [-]Transport of organic contaminants in subsoil horizons and effects of dissolved organic matter related to organic waste recycling practices
2016
Chabauty, Florian | Pot-Genty, Valerie | Deschamps, Marjolaine | Bernet, Nathalie | Labat, Christophe | Benoit, Pierre | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Université Paris-Saclay | European Commission [226536]; Ile-de-France region; Veolia Environment group Funding Text : The work was carried as part of the GENESIS project on groundwater systems financed by the European Commission 7thFP contract 226536. The authors also acknowledge the Ile-de-France region for funding for ultra-performance liquid chromatography/MS-MS analyses, and the useful help of Jean-Noel Rampon for field sampling. Finally, we acknowledge the Veolia Environment group for the financial support of the QualiAgro field site.
Compost amendment on agricultural soil is a current practice to compensate the loss of organic matter. As a consequence, dissolved organic carbon concentration in soil leachates can be increased and potentially modify the transport of other solutes. This study aims to characterize the processes controlling the mobility of dissolved organic matter (DOM) in deep soil layers and their potential impacts on the leaching of organic contaminants (pesticides and pharmaceutical compounds) potentially present in cultivated soils receiving organic waste composts. We sampled undisturbed soil cores in the illuviated horizon (60-90 cm depth) of an Albeluvisol. Percolation experiments were made in presence and absence of DOM with two different pesticides, isoproturon and epoxiconazole, and two pharmaceutical compounds, ibuprofen and sulfamethoxazole. Two types of DOM were extracted from two different soil surface horizons: one sampled in a plot receiving a co-compost of green wastes and sewage sludge applied once every 2 years since 1998 and one sampled in an unamended plot. Results show that DOM behaved as a highly reactive solute, which was continuously generated within the soil columns during flow and increased after flow interruption. DOM significantly increased the mobility of bromide and all pollutants, but the effects differed according the hydrophobic and the ionic character of the molecules. However, no clear effects of the origin of DOM on the mobility of the different contaminants were observed.
اظهر المزيد [+] اقل [-]Soil microbial respiration and PICT responses to an industrial and historic lead pollution: a field study
2016
Berard, Annette | Capowiez, Line | Mombo, Stéphane | Schreck, Eva | Dumat, Camille | Deola, Frederic | Capowiez, Yvan | Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT) | Laboratoire Ecologie Fonctionnelle et Environnement (LEFE) ; Institut Ecologie et Environnement (INEE) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT) | Géosciences Environnement Toulouse (GET) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) | Centre d'Etude et de Recherche Travail Organisation Pouvoir (CERTOP) ; Université Toulouse - Jean Jaurès (UT2J) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS) | Unité de recherche Plantes et Systèmes de Culture Horticoles (PSH) ; Institut National de la Recherche Agronomique (INRA) | We gratefully acknowledge ADEME (French Agency of the Environment and Energy) as well as the company STCM (Société de Traitements Chimiques des Métaux) for their technical help and financial support. This work was also supported by the INSU-EC2CO program (Biotuba Project)
International audience | no abstract
اظهر المزيد [+] اقل [-]Pollution-induced community tolerance (PICT) as a tool for monitoring Lake Geneva long-term in situ ecotoxic restoration from herbicide contamination
2016
Larras, Floriane | Rimet, Frédéric | Gregorio, V. | Berard, Annette, A. | Leboulanger, C. | Montuelle, Bernard | Bouchez, Agnes | Centre Alpin de Recherche sur les Réseaux Trophiques et Ecosystèmes Limniques (CARRTEL) ; Institut National de la Recherche Agronomique (INRA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry]) | Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC) ; Institut Ecologie et Environnement (INEE) ; Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo) ; Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS) | Institut des sciences de la terre [Lausanne] (ISTE) ; Université de Lausanne = University of Lausanne (UNIL) | Environnement Méditerranéen et Modélisation des Agro-Hydrosystèmes (EMMAH) ; Avignon Université (AU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | MARine Biodiversity Exploitation and Conservation (UMR MARBEC) ; Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS) | This work is part of the IMPALAC program funded by The Ministere Francais de l'Ecologie et du Developpement Durable (convention 2100212555)
International audience | Chemical monitoring revealed a regular decrease in herbicide concentration in Lake Geneva since last decades that may be linked to an ecotoxic restoration of nontarget phytoplanktonic communities. The Pollution-induced community tolerance (PICT) approach was tested as a tool to monitor the ecotoxic restoration of Lake Geneva for herbicides from 1999 to 2011. We conducted monthly assessments in 1999 and in 2011 for the tolerance of the phytoplankton communities to two herbicides (atrazine and copper), using PICT bioassays. The taxonomical composition of the communities was determined on the same collecting dates. The herbicide concentration decrease during the 12 years significantly influenced the composition of communities. The PICT monitoring indicated that a significant tolerance decrease in the community to both herbicides accompanied the herbicide concentration decrease. PICT measurements for atrazine and copper also changed at the intra-annual level. These variations were mainly due to community composition shifts linked to seasonal phosphorus and temperature changes. PICT monitoring on a seasonal basis is required to monitor the mean tolerance of communities. PICT appeared to be a powerful tool that reflected the toxic effects on environmental communities and to monitor ecotoxic ecosystem restoration.
اظهر المزيد [+] اقل [-]Evaluation of the ecotoxicological impact of the organochlorine chlordecone on soil microbial community structure, abundance, and function
2016
Merlin, Chloé | Devers, Marion | Béguet, Jérémie | Boggio, Baptiste | Rouard, Nadine | Martin-Laurent, Fabrice | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | ADEME/Region Bourgogne grant ; "Biodechlord project" - INRA AIP Demichlord part of PNAC 1
International audience | The insecticide chlordecone applied for decades in banana plantations currently contaminates 20,000 ha of arable land in the French West Indies. Although the impact of various pesticides on soil microorganisms has been studied, chlordecone toxicity to the soil microbial community has never been assessed. We investigated in two different soils (sandy loam and silty loam) exposed to different concentrations of CLD (D0, control; D1 and D10, 1 and 10 times the agronomical dose) over different periods of time (3, 7, and 32 days): (i) the fate of chlordecone by measuring C-14-chlordecone mass balance and (ii) the impact of chlordecone on microbial community structure, abundance, and function, using standardized methods (-A-RISA, taxon-specific quantitative PCR (qPCR), and C-14-compounds mineralizing activity). Mineralization of C-14-chlordecone was inferior below 1 % of initial C-14-activity. Less than 2 % of C-14-activity was retrieved from the water-soluble fraction, while most of it remained in the organic-solvent-extractable fraction (75 % of initial C-14-activity). Only 23 % of the remaining C-14-activity was measured in nonextractable fraction. The fate of chlordecone significantly differed between the two soils. The soluble and nonextractable fractions were significantly higher in sandy loam soil than in silty loam soil. All the measured microbiological parameters allowed discriminating statistically the two soils and showed a variation over time. The genetic structure of the bacterial community remained insensitive to chlordecone exposure in silty loam soil. In response to chlordecone exposure, the abundance of Gram-negative bacterial groups (beta-, gamma-Proteobacteria, Planctomycetes, and Bacteroidetes) was significantly modified only in sandy loam soil. The mineralization of C-14-sodium acetate and C-14-2,4-d was insensitive to chlordecone exposure in silty loam soil. However, mineralization of C-14-sodium acetate was significantly reduced in soil microcosms of sandy loam soil exposed to chlordecone as compared to the control (D0). These data show that chlordecone exposure induced changes in microbial community taxonomic composition and function in one of the two soils, suggesting microbial toxicity of this organochlorine.
اظهر المزيد [+] اقل [-]Toxicity assessment of four insecticides with different modes of action on pupae and adults of Eriopis connexa (Coleoptera: Coccinellidae), a relevant predator of the Neotropical Region
2016
Noelia Fogel, Marilina | Ines Schneider, Marcela | Rimoldi, Federico | Sabrina Ladux, Lorena | Desneux, Nicolas | Estela Ronco, Alicia | Universidad Nacional de la Plata [Argentine] (UNLP) | Institut Sophia Agrobiotech (ISA) ; Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS)-Centre National de la Recherche Scientifique (CNRS) | Argentine National Agency for the Promotion of Science and Technology (ANPCyT-FONCyT) [PICT 2010-0891-, PICT 2011-1752-BID]; National Council of Scientific and Technical Research (CONICET)
International audience | Pesticides can be toxic to nontarget organisms including the natural enemies of agricultural pests, thus reducing the biodiversity of agroecosystems. The lethal and sublethal effects of four insecticides with different modes of action-pyriproxyfen, teflubenzuron, acetamiprid, and cypermethrin-were evaluated on pupae and adults of Eriopis connexa, an effective predator in horticultural crops. Pupal survival was reduced by pyriproxyfen (26 %) and cypermethrin (41 %). Malformations in adults emerged from treated pupae were observed after acetamiprid (82.7 and 100 % for 100 and 200 mg a.i./l, respectively), pyriproxyfen (48.6 %), and cypermethrin (13.3 %) treatments. A longer mean oviposition time was also observed in adults emerged from pupae treated with cypermethrin. Moreover, the latter insecticide as well as teflubenzuron did not reduce reproductive parameters, whereas females emerged from pyriproxyfen-treated pupae were not be able to lay eggs even when females showed large abdomens. Upon exposure of adults, survival was reduced to approximately 90 % by acetamiprid, but no reduction occurred with pyriproxyfen, teflubenzuron, or cypermethrin though the fecundity at fifth oviposition time of the female survivors was reduced. Pyriproxyfen decreased the hatching at all the oviposition times tested, whereas fertility was reduced in the fourth and fifth ovipositions by teflubenzuron and in the first and third ovipositions by cypermethrin. In conclusion, all four insecticides tested exhibited lethal or sublethal effects, or both, on E. connexa. The neurotoxic insecticides were more harmful than the insect-growth regulators, and pupae were more susceptible than adults. The toxicity of insecticides on the conservation of predators in agroecosystems of the Neotropical Region is discussed.
اظهر المزيد [+] اقل [-]Nicosulfuron application in agricultural soils drives the selection towards NS-tolerant microorganisms harboring various levels of sensitivity to nicosulfuron
2016
Petric, Ines | Karpouzas, Dimitrios G. | Bru, David | Udikovic-Kolic, Nikolina | Kandeler, Ellen | Djuric, Simonida | Martin-Laurent, Fabrice | Division for Marine and Environmental Research ; Rudjer Boskovic Institute [Zagreb] | Department of Biochemistry and Biotechnology ; University of Thessaly | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | Institute of Soil Science and Land Evaluation, Soil Biology Section ; University of Hohenheim | Univ Novi Sad, Fac Agr, Novi Sad 21000, Serbia ; Partenaires INRAE
International audience | The action mode of sulfonylurea herbicides is the inhibition of the acetohydroxyacid synthase (AHAS) required for the biosynthesis of amino acids valine and isoleucine in plants. However, this enzyme is also present in a range of non-targeted organisms, among which soil microorganisms are known for their pivotal role in ecosystem functioning. In order to assess microbial toxicity of sulfonylurea herbicide nicosulfuron (NS), a tiered microcosm (Tier I) to field (Tier II) experiment was designed. Soil bacteria harboring AHAS enzyme tolerant to the herbicide nicosulfuron were enumerated, isolated, taxonomically identified, and physiologically characterized. Results suggested that application of nicosulfuron drives the selection towards NS-tolerant bacteria, with increasing levels of exposure inducing an increase in their abundance and diversity in soil. Tolerance to nicosulfuron was shown to be widespread among the microbial community with various bacteria belonging to Firmicutes (Bacillus) and Actinobacteria (Arthrobacter) phyla representing most abundant and diverse clusters. While Arthrobacter bacterial population dominated community evolved under lower (Tier II) nicosulfuron selection pressure, it turns out that Bacillus dominated community evolved under higher (Tier I) nicosulfuron selection pressure. Different NS-tolerant bacteria likewise showed different levels of sensitivity to the nicosulfuron estimated by growth kinetics on nicosulfuron. As evident, Tier I exposure allowed selection of populations able to better cope with nicosulfuron. One could propose that sulfonylureas-tolerant bacterial community could constitute a useful bioindicator of exposure to these herbicides for assessing their ecotoxicity towards soil microorganisms.
اظهر المزيد [+] اقل [-]Use of fallout radionuclides (7Be, 210Pb) to estimate resuspension of Escherichia coli from streambed sediments during floods in a tropical montane catchment
2016
Ribolzi, Olivier | Evrard, O. | Huon, Sylvain | Rochelle-Newall, Emma | Henri-Des-Tureaux, Thierry | Silvera, Norbert | Thammahacksac, Chanthamousone | Sengtaheuanghoung, Oloth | Géosciences Environnement Toulouse (GET) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) ; Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) | Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) | Géochimie Des Impacts (GEDI) ; Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE) ; Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)) ; Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA) | Institut d'écologie et des sciences de l'environnement de Paris (iEES) ; Institut National de la Recherche Agronomique (INRA)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS) | Institut de Recherche pour le Développement (IRD) | Department of Agricultural Land Management (DALaM) | Lao Department of Agriculture Land Management (DALAM) ; MSEC project (Multi-Scale Environment Changes) ; French Centre National de la Recherche Scientifique EC2CO/BIOHEFECT program (Belcrue project) ; French Centre National de la Recherche Scientifique EC2CO/BIOHEFECT program (Belkong project) ; French National Research Agency [ANR-13-AGRO-0007] | ANR-13-AGRO-0007,TecItEasy,Effets conjugués de l'expansion des plantations d'arbres et du changement climatique sur le fonctionnement hydro-sédimentaire des bassins versants tropicaux de montagne: la diversité microbienne aquatique comme un proxy de la conversion d'usage des terres(2013)
International audience | Consumption of water polluted by faecal contaminants is responsible for 2 million deaths annually, most of which occur in developing countries without adequate sanitation. In tropical aquatic systems, streambeds can be reservoirs of persistent pathogenic bacteria and high rainfall can lead to contaminated soils entering streams and to the resuspension of sediment-bound microbes in the streambed. Here, we present a novel method using fallout radionuclides (Be-7 and Pb-210(xs)) to estimate the proportions of Escherichia coli, an indicator of faecal contamination, associated with recently eroded soil particles and with the resuspension of streambed sediments. We show that using these radionuclides and hydrograph separations we are able to characterize the proportion of particles originating from highly contaminated soils and that from the resuspension of particle-attached bacteria within the streambed. We also found that although overland flow represented just over one tenth of the total flood volume, it was responsible for more than two thirds of the downstream transfer of E. coli. We propose that data obtained using this method can be used to understand the dynamics of faecal indicator bacteria (FIB) in streams thereby providing information for adapted management plans that reduce the health risks to local populations.
اظهر المزيد [+] اقل [-]Use of RSM modeling for optimizing decolorization of simulated textile wastewater by Pseudomonas aeruginosa strain ZM130 capable of simultaneous removal of reactive dyes and hexavalent chromium
2016
Maqbool, Zahid | Hussain, Sabir | Ahmad, Tanvir | Nadeem, Habibullah | Imran, Muhammad | Khalid, Azeem | Abid, Muhammad | Martin-Laurent, Fabrice | Department of Environmental Sciences and Engineering ; University of North Carolina [Chapel Hill] (UNC) ; University of North Carolina System (UNC)-University of North Carolina System (UNC) | University College Dublin (UCD) | Government College University | Nuclear Institute for Agriculture and Biology ; Partenaires INRAE | Muhammad Nawaz Shareef University of Agriculture | Pir Mehr Ali Shah Arid Agriculture University = PMAS-Arid Agriculture University Rawalpindi (AAUR) | Bahauddin Zakariya University (BZU) | Agroécologie [Dijon] ; Institut National de la Recherche Agronomique (INRA)-Université de Bourgogne (UB)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement | Higher Education Commission (HEC) of Pakistan; Government College University Faisalabad, Pakistan
International audience | Remediation of colored wastewater loaded with dyes and metal ions is a matter of interest nowadays. In this study, 220 bacteria isolated from textile wastewater were tested for their potential to decolorize each of the four reactive dyes (reactive red-120, reactive black-5, reactive yellow-2, and reactive orange-16) in the presence of a mixture of four different heavy metals (Cr, Zn, Pb, Cd) commonly found in textile effluents. Among the tested bacteria, the isolate ZM130 was found to be the most efficient in decolorizing reactive dyes in the presence of the mixture of heavy metals and was identified as Pseudomonas aeruginosa strain ZM130 by 16S rRNA gene analysis. The strain ZM130 was highly effective in simultaneously removing hexavalent chromium (25 mg L-1) and the azo dyes (100 mg L-1) from the simulated wastewater even in the presence of other three heavy metals (Zn, Pb, Cd). Simultaneous removal of chromium and azo dyes ranged as 76.6-98.7 % and 51.9-91.1 %, respectively, after 180 h incubation. On the basis of quadratic polynomial equation and response surfaces given by the response surface methodology (RSM), optimal salt content, pH, carbon co-substrate content, and level of multi-metal mixtures for decolorization of reactive red-120 in a simulated textile wastewater by the strain ZM130 were predicted to be 19.8, 7.8, and 6.33 g L-1 and a multi-metal mixture (Cr 13.10 mg L-1, Pb 26.21 mg L-1, Cd 13.10 mg L-1, Zn 26.21 mg L-1), respectively. Moreover, the strain ZM130 also exhibited laccase and nicotinamide adenine dinucleotide (reduced)-dichlorophenolindophenol reductase (NADH-DCIP reductase) activity during the decolorization of reactive red-120. However, the laccase activity was found to be maximum in the presence of 300 mg L-1 of the dye as compared to other concentrations. Hence, the isolation of this strain might serve as a potential bio-resource required for developing the strategies aiming at bioremediation of the wastewater contaminated with dyes and heavy metals.
اظهر المزيد [+] اقل [-]