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Integrated modeling of agricultural scenarios (IMAS) to support pesticide action plans: the case of the Coulonge drinking water catchment area (SW France) | Modélisation intégrée de scénarios agricoles (IMAS) pour l'aide à la décision publique : le cas de l'aire d'alimentation de captage de Coulonge St Hippolyte (SO France)
2017
Vernier, Françoise | Leccia-Phelpin, Odile | Lescot, Jean-Marie | Minette, Sebastien | Miralles, A. | Barberis, Delphine | Scordia, C. | Kuentz Simonet, V. | Tonneau, J.P. | Environnement, territoires et infrastructures (UR ETBX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | CHAMBRE REGIONALE D'AGRICULTURE MIGNALOUX BEAUVOIR FRA ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)
[Departement_IRSTEA]Territoires [TR1_IRSTEA]DTAM [Axe_IRSTEA]DTAM-QT2-ADAPTATION [TR2_IRSTEA]SYNERGIE | International audience | Non-point source pollution is a cause of major concern within the European Union. This is reflected in increasing public and political focus on a more sustainable use of pesticides, as well as a reduction in diffuse pollution. Climate change will likely to lead to an even more intensive use of pesticides in the future, affecting agriculture in many ways. At the same time, the Water Framework Directive (WFD) and associated EU policies called for a “good” ecological and chemical status to be achieved for water bodies by the end of 2015, currently delayed to 2021–2027 due to a lack of efficiency in policies and timescale of resilience for hydrosystems, especially groundwater systems. Water managers need appropriate and user-friendly tools to design agro-environmental policies. These tools should help them to evaluate the potential impacts of mitigation measures on water resources, more clearly define protected areas, and more efficiently distribute financial incentives to farmers who agree to implement alternative practices. At present, a number of reports point out that water managers do not use appropriate information from monitoring or models to make decisions and set environmental action plans. In this paper, we propose an integrated and collaborative approach to analyzing changes in land use, farming systems, and practices and to assess their effects on agricultural pressure and pesticide transfers to waters. The integrated modeling of agricultural scenario (IMAS) framework draws on a range of data and expert knowledge available within areas where a pesticide action plan can be defined to restore the water quality, French “Grenelle law” catchment areas, French Water Development and Management Plan areas, etc. A so-called “reference scenario” represents the actual soil occupation and pesticide-spraying practices used in both conventional and organic farming. A number of alternative scenarios are then defined in cooperation with stakeholders, including socio-economic conditions for developing alternative agricultural systems or targeting mitigation measures. Our integrated assessment of these scenarios combines the calculation of spatialized environmental indicators with integrated bio-economic modeling. The latter is achieved by a combined use of Soil and Water Assessment Tool (SWAT) modeling with our own purpose-built land use generator module (Generator of Land Use version 2 (GenLU2)) and an economic model developed using General Algebraic Modeling System (GAMS) for cost-effectiveness assessment. This integrated approach is applied to two embedded catchment areas (total area of 360,000 ha) within the Charente river basin (SW France). Our results show that it is possible to differentiate scenarios based on their effectiveness, represented by either evolution of pressure (agro-environmental indicators) or transport into waters (pesticide concentrations). By analyzing the implementation costs borne by farmers, it is possible to identify the most cost-effective scenarios at sub-basin and other aggregated levels (WFD hydrological entities, sensitive areas). Relevant results and indicators are fed into a specifically designed database. Data warehousing is used to provide analyses and outputs at all thematic, temporal, or spatial aggregated levels, defined by the stakeholders (type of crops, herbicides, WFD areas, years), using Spatial On-Line Analytical Processing (SOLAP) tools. The aim of this approach is to allow public policy makers to make more informed and reasoned decisions when managing sensitive areas and/or implementing mitigation measures.
Show more [+] Less [-]Wood-derived-biochar combined with compost or iron grit for in situ stabilization of Cd, Pb, and Zn in a contaminated soil
2017
Oustrière, Nadège | Marchand, Lilian | Rosette, Gabriel | Friesl-Hanl, Wolfgang | Mench, Michel | Biodiversité, Gènes & Communautés (BioGeCo) ; Institut National de la Recherche Agronomique (INRA)-Université de Bordeaux (UB) | Energy Department ; Politecnico di Milano [Milan] (POLIMI)
In situ stabilization of Cd, Pb, and Zn in an Austrian agricultural soil contaminated by atmospheric depositions from a smelter plant was assessed with a pine bark chip-derived biochar, alone and in combination with either compost or iron grit. Biochar amendment was also trialed in an uncontaminated soil to detect any detrimental effect. The pot experiment consisted in ten soil treatments (% w/w): untreated contaminated soil (Unt); Unt soil amended with biochar alone (1%: B1; 2.5%: B2.5) and in combination: B1 and B2.5 + 5% compost (B1C and B2.5C), B1 and B2.5 + 1% iron grit (B1Z and B2.5Z); uncontaminated soil (Ctrl); Ctrl soil amended with 1 or 2.5% biochar (CtrlB1, CtrlB2.5). After a 3-month reaction period, the soil pore water (SPW) was sampled in potted soils and dwarf beans were grown for a 2-week period. The SPW Cd, Pb, and Zn concentrations decreased in all amended-contaminated soils. The biochar effects increased with its addition rate and its combination with either compost or iron grit. Shoot Cd and Zn removals by beans were reduced and shoot Cd, Pb, and Zn concentrations decreased to common values in all amended soils except the B1 soil. Decreases in the SPW Cd/Pb/Zn concentrations did not improve the root and shoot yields of plants as compared to the Ctrl soil.
Show more [+] Less [-]Tolerance of Japanese knotweed s.l. to soil artificial polymetallic pollution: early metabolic responses and performance during vegetative multiplication
2017
Michalet, Serge | Rouifed, Soraya | Pellassa-Simon, Thomas | Fusade-Boyer, Manon | Meiffren, Guillaume | Nazaret, Sylvie | Piola, Florence | Laboratoire d'Ecologie Microbienne - UMR 5557 (LEM) ; Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Ecole Nationale Vétérinaire de Lyon (ENVL)-VetAgro Sup - Institut national d'enseignement supérieur et de recherche en alimentation, santé animale, sciences agronomiques et de l'environnement (VAS)-Centre National de la Recherche Scientifique (CNRS) | Équipe 2 - Écologie Végétale et Zones Humides (EVZH) ; Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS)-Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS) | Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS) | Initiative Structurante EC2CO (Ecosphere Continentale et Cotiere); ECODYN (Ecotoxicologie, Ecodynamique des contaminants); FR3728 BioEnviS
International audience | The expansion of invasive Japanese Knotweed s.l. is of particular concern because of its aptitudes to rapidly colonize diverse environments, especially anthropized habitats generally characterized by their pollution with heavy metals. Whether the presence of heavy metals impacts the performance traits of this plant is a central question to better understand its invasive properties, though no controlled approach to assess these effects were yet reported. In this aim, we undertook greenhouse experiments where rhizome fragments of Japanese Knotweed s.l. (Fallopia japonica and Fallopia x bohemica) were grown during 1 and 3 months, in soil pot artificially polluted or not with heavy metals added in mixture (Cd, Cr, Pb, Zn). Our results showed that (i) the presence of heavy metals delayed rhizome regeneration and induced lowered plant part weights but did not affect plant height after three months; (ii) the effect of metals on the metabolic profiles of belowground part extracts was only detectable after 1 month and not after 3 months of growth, though, it was possible to highlight the effect of metals independently of time and genotype for root extracts, and torosachrysone seemed to be the most induced compound; (iii) the hybrid genotype tested was able to accumulate relatively high concentrations of metals, over or close to the highest reported ones for this plant for Cr, Cd and Zn, whereas Pb was not accumulated. These findings evidence that the presence of heavy metals in soil has a low impact on Fallopia spp. overall performance traits during rhizome regeneration, and has a rather stimulating effect on plant growth depending on pollution level.
Show more [+] Less [-]Observed volatilization fluxes of S-metolachlor and benoxacor applied on soil with and without crop residues
2017
Bedos, Carole | Alletto, Lionel | Durand, Brigitte | Fanucci, Olivier | Brut, Aurore | Deschamps, Marjolaine | Giuliano, Simon | Loubet, Benjamin | Ceschia, Eric | Benoit, Pierre | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | AGroécologie, Innovations, teRritoires (AGIR) ; Institut National de la Recherche Agronomique (INRA)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT) | Centre d'études spatiales de la biosphère (CESBIO) ; 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 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 de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE) | Institut Universitaire de Technologie - Paul Sabatier (IUT Paul Sabatier) ; Université Toulouse III - Paul Sabatier (UT3) ; Université de Toulouse (UT)-Université de Toulouse (UT)
Volatilization may represent a major dissipation pathway for pesticides applied to soils or crops, and these losses may be modified by soil surface conditions or in the presence of plant residues. This paper investigates the effect of surface conditions on volatilization through experimental results. The two experiments consisted of volatilization flux measurements for 3 days after an application of S-metolachlor together with benoxacor: one with two wind tunnels to compare the effect of the presence of crop residues on the soil on volatilization losses and another one at the field scale from bare soil without crop residues. Volatilization fluxes were large immediately after application (between 77 and 223 ng m−2 s−1 for S-metolachlor depending on experimental conditions), decreasing down to a few nanograms per square meter per second on the last day. Volatilization fluxes followed a diurnal cycle driven by environmental conditions. The losses found for both compounds were in accordance with their physicochemical properties. The crop residue on the soil surface modified soil surface conditions—primarily the soil water content essentially, the degradation of S-metolachlor, and the dynamics of volatilization loss.
Show more [+] Less [-]Simulating changes in cropping practises in conventional and glyphosate-tolerant maize. I. Effects on weeds
2017
Colbach, Nathalie | Fernier, Alice | Le Corre, Valérie | Messean, Antoine | Darmency, Henri | 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-Université Bourgogne Franche-Comté [COMUE] (UBFC) | Unité Impacts Ecologiques des Innovations en Production Végétale (ECO-INNOV) ; Institut National de la Recherche Agronomique (INRA)
EASPEGESTADSUPDATINRACT1EJ2 INRA | Herbicide-tolerant (HT) crops such as those tolerant to glyphosate simplify weed management and make it more efficient, at least at short-term. Overreliance on the same herbicide though leads to the spread of resistant weeds. Here, the objective was to evaluate, with simulations, the impact on the advent of glyphosate resistance in weeds of modifications in agricultural practises resulting from introducing HT maize into cropping systems. First, we included a single-gene herbicide resistance submodel in the existing multispecific FLORSYS model. Then, we (1) simulated current conventional and probable HT cropping systems in two European regions, Aquitaine and Catalonia, (2) compared these systems in terms of glyphosate resistance, (3) identified pertinent cultural practises influencing glyphosate resistance, and (4) investigated correlations between cultural practises and species traits, using RLQ analyses. The simulation study showed that, during the analysed 28years, (1) glyphosate spraying only results in glyphosate resistance in weeds when combined with other cultural factors favouring weed infestation, particularly no till; (2) pre-sowing glyphosate applications select more for herbicide resistance than post-sowing applications on HT crops; and (3) glyphosate spraying selects more for species traits avoiding exposure to the herbicide (e.g. delayed early growth, small leaf area) or compensating for fitness costs (e.g. high harvest index) than for actual resistance to glyphosate, (4) actual resistance is most frequent in species that do not avoid glyphosate, either via plant size or timing, and/or in less competitive species, (5) in case of efficient weed control measures, actual resistance proliferates best in outcrossing species. An advice table was built, with the quantitative, synthetic ranking of the crop management effects in terms of glyphosate-resistance management, identifying the optimal choices for each management technique.
Show more [+] Less [-]Agricultural effluent treatment in biobed systems using novel substrates from southeastern Mexico: the relationship with physicochemical parameters of biomixtures
2017
Góngora-Echeverría, Virgilio René | Martin-Laurent, Fabrice | Quintal-Franco, Carlos | Giácoman-Vallejos, German | Ponce-Caballero, Carmen | Facultad de Ingeniería ; Universidad de la República [Montevideo] (UDELAR) | 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-Université Bourgogne Franche-Comté [COMUE] (UBFC)
EABIOmE INRA | Misuse of pesticides in farming activities leads to contamination of drinking water sources and is responsible for animal and human health problems. The biobeds are practicable option to minimize contamination by pesticides during preparation, use and washing of equipment for pesticide treatments. This research aimed at testing substrate mixtures to optimize biobed efficiency to remove pesticides under the climate of the Yucatan (México). Agricultural soil and 11 mixtures adding vegetable compost, sisal pulp, corn stover and seaweed were tested under controlled conditions. Each biomixture was exposed to a mixture of five pesticides (2,4-diclorophenoxyacetic acid “2,4-D” [1.08 mg cm−3], atrazine [2.50 mg cm−3], carbofuran [0.23 mg cm−3], diazinon [0.34 mg cm−3], and glyphosate [0.36 mg cm−3]) in a period of 41 days. Monitoring of the dissipation of pesticide residues showed that pesticides were quickly dissipated in soil at microcosm level experiment, while at two critical times of 20 and 41 days, all mixtures of substrates (biomixtures) were efficient in dissipation of high concentrations of pesticide in a short time (>99%). Time, biomixture and type of pesticide were shown to be the main parameters influencing pesticide dissipation (P < 0.05). Several other physicochemical parameters of the biomixtures, such as organic matter (OM), lignin, water holding capacity (WHC), and pH, were also significant on pesticide dissipation (P < 0.05), being pH the most significant.
Show more [+] Less [-]Sequential use of the STICS crop model and of the MACRO pesticide fate model to simulate pesticides leaching in cropping systems
2017
Lammoglia, Sabine-Karen | Moeys, Julien | Barriuso, Enrique | Larsbo, Mats | Marín-Benito, Jesús-María | Justes, Eric | Alletto, Lionel | Ubertosi, Marjorie | Nicolardot, Bernard | Munier-Jolain, Nicolas | Mamy, Laure | Ecologie fonctionnelle et écotoxicologie des agroécosystèmes (ECOSYS) ; Institut National de la Recherche Agronomique (INRA)-AgroParisTech | Departement of Soil and Environment ; Swedish University of Agricultural Sciences (SLU) | CSIC40-52 Cordel de Merinas ; Institute of Natural Resources and Agrobiology of Salamanca (IRNASA) | AGroécologie, Innovations, teRritoires (AGIR) ; Institut National de la Recherche Agronomique (INRA)-Institut National Polytechnique (Toulouse) (Toulouse INP) ; Université de Toulouse (UT)-Université de Toulouse (UT) | 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-Université Bourgogne Franche-Comté [COMUE] (UBFC)
International audience | The current challenge in sustainable agriculture is to introduce new cropping systems to reduce pesticides use in order to reduce ground and surface water contamination. However, it is difficult to carry out in situ experiments to assess the environmental impacts of pesticide use for all possible combinations of climate, crop, and soils; therefore, in silico tools are necessary. The objective of this work was to assess pesticides leaching in cropping systems coupling the performances of a crop model (STICS) and of a pesticide fate model (MACRO). STICS-MACRO has the advantage of being able to simulate pesticides fate in complex cropping systems and to consider some agricultural practices such as fertilization, mulch, or crop residues management, which cannot be accounted for with MACRO. The performance of STICS-MACRO was tested, without calibration, from measurements done in two French experimental sites with contrasted soil and climate properties. The prediction of water percolation and pesticides concentrations with STICS-MACRO was satisfactory, but it varied with the pedoclimatic context. The performance of STICS-MACRO was shown to be similar or better than that of MACRO. The improvement of the simulation of crop growth allowed better estimate of crop transpiration therefore of water balance. It also allowed better estimate of pesticide interception by the crop which was found to be crucial for the prediction of pesticides concentrations in water. STICS-MACRO is a new promising tool to improve the assessment of the environmental risks of pesticides used in cropping systems.
Show more [+] Less [-]Integrated modeling of agricultural scenarios (IMAS) to support pesticide action plans: the case of the Coulonge drinking water catchment area (SW France) | Modélisation intégrée de scénarios agricoles (IMAS) pour l'aide à la décision publique : le cas de l'aire d'alimentation de captage de Coulonge St Hippolyte (SO France)
2017
Vernier, Françoise | Leccia-Phelpin, Odile | Lescot, Jean-Marie | Minette, Sebastien | Miralles, A. | Barberis, Delphine | Scordia, C. | Kuentz Simonet, V. | Tonneau, J.P. | Environnement, territoires et infrastructures (UR ETBX) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | CHAMBRE REGIONALE D'AGRICULTURE MIGNALOUX BEAUVOIR FRA ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Territoires, Environnement, Télédétection et Information Spatiale (UMR TETIS) ; Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)
[Departement_IRSTEA]Territoires [TR1_IRSTEA]DTAM [Axe_IRSTEA]DTAM-QT2-ADAPTATION [TR2_IRSTEA]SYNERGIE | International audience | Non-point source pollution is a cause of major concern within the European Union. This is reflected in increasing public and political focus on a more sustainable use of pesticides, as well as a reduction in diffuse pollution. Climate change will likely to lead to an even more intensive use of pesticides in the future, affecting agriculture in many ways. At the same time, the Water Framework Directive (WFD) and associated EU policies called for a “good” ecological and chemical status to be achieved for water bodies by the end of 2015, currently delayed to 2021–2027 due to a lack of efficiency in policies and timescale of resilience for hydrosystems, especially groundwater systems. Water managers need appropriate and user-friendly tools to design agro-environmental policies. These tools should help them to evaluate the potential impacts of mitigation measures on water resources, more clearly define protected areas, and more efficiently distribute financial incentives to farmers who agree to implement alternative practices. At present, a number of reports point out that water managers do not use appropriate information from monitoring or models to make decisions and set environmental action plans. In this paper, we propose an integrated and collaborative approach to analyzing changes in land use, farming systems, and practices and to assess their effects on agricultural pressure and pesticide transfers to waters. The integrated modeling of agricultural scenario (IMAS) framework draws on a range of data and expert knowledge available within areas where a pesticide action plan can be defined to restore the water quality, French “Grenelle law” catchment areas, French Water Development and Management Plan areas, etc. A so-called “reference scenario” represents the actual soil occupation and pesticide-spraying practices used in both conventional and organic farming. A number of alternative scenarios are then defined in cooperation with stakeholders, including socio-economic conditions for developing alternative agricultural systems or targeting mitigation measures. Our integrated assessment of these scenarios combines the calculation of spatialized environmental indicators with integrated bio-economic modeling. The latter is achieved by a combined use of Soil and Water Assessment Tool (SWAT) modeling with our own purpose-built land use generator module (Generator of Land Use version 2 (GenLU2)) and an economic model developed using General Algebraic Modeling System (GAMS) for cost-effectiveness assessment. This integrated approach is applied to two embedded catchment areas (total area of 360,000 ha) within the Charente river basin (SW France). Our results show that it is possible to differentiate scenarios based on their effectiveness, represented by either evolution of pressure (agro-environmental indicators) or transport into waters (pesticide concentrations). By analyzing the implementation costs borne by farmers, it is possible to identify the most cost-effective scenarios at sub-basin and other aggregated levels (WFD hydrological entities, sensitive areas). Relevant results and indicators are fed into a specifically designed database. Data warehousing is used to provide analyses and outputs at all thematic, temporal, or spatial aggregated levels, defined by the stakeholders (type of crops, herbicides, WFD areas, years), using Spatial On-Line Analytical Processing (SOLAP) tools. The aim of this approach is to allow public policy makers to make more informed and reasoned decisions when managing sensitive areas and/or implementing mitigation measures.
Show more [+] Less [-]Nanoscale zero-valent iron functionalized Posidonia oceanica marine biomass for heavy metal removal from water
2017
Boubakri, Saber | Djebbi, Mohamed Amine | Bouaziz, Zaineb | Namour, Philippe | Ben Haj Amara, Abdesslem | Ghorbel-Abid, Ibtissem | Kalfat, Rafik | LABORATOIRE MATERIAUX TRAITEMENT ET ANALYSE INSTITUT NATIONAL DE RECHERCHE ET D'ANALYSE PHYSICOCHIMIQUE BIOTECHPOLE SIDI THABET ARIANA TUN ; Partenaires IRSTEA ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA) | Faculté des Sciences de Bizerte [Université de Carthage] ; Université de Carthage (Tunisie) (UCAR) | Institut des Sciences Analytiques (ISA) ; Université Claude Bernard Lyon 1 (UCBL) ; Université de Lyon-Université de Lyon-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS) | RiverLy (UR Riverly) ; Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCA | International audience | Because of the excellent reducing capacity of nanoscale zero-valent iron (NZVI), it can be used as alternative materials for the removal of a variety of reducible water contaminants including toxic metals. The current paper reports the research results obtained for self-prepared biosorbent, Posidonia oceanica biomass, activated in alkaline medium and functionalized with NZVI particles. The structural characteristics, surface morphology, and binding properties of the resulting nanobiosorbent are presented. Batch comparative adsorption trials including adsorption kinetics and isothermals onto raw Posidonia, Posidonia-OH and Posidonia-OH-NZVI were investigated on three heavy metal ions: Cd(II), Pb(II), and Cu(II). The nanobiosorbent showed better properties, such as high reactivity and high uptake rate through the sorption process. The toxic metal removal has been monitored in terms of pseudo-first- and pseudo-second-order kinetics, and both Langmuir- and Freundlich-type isotherm models have been used to describe the sorption mechanism. The experimental data of all studied systems showed that the uptake kinetics follow the pseudo-second-order kinetic model and the equilibrium uptake can adopt the Langmuir-type isotherm model which assumes a monolayer coverage as the adsorption saturates and no further adsorption occurs. The thermodynamic results confirm that all sorption processes were feasible, spontaneous and thermodynamically favorable. Zeta potential data displayed that Cd(II), Pb(II), and Cu(II) tend to be reduced after exposure on the Posidonia-OH-NZVI surface. Furthermore, sorption competitions of the metals from binary and ternary systems were carried out onto Posidonia-OH-NZVI in order to gain further insight into the sorption efficiency of this material. Therefore, as a result, the proposed new nanobiosorbent could offer potential benefits in remediation of heavy metal-contaminated water as a green and environmentally friendly bionanocomposite.
Show more [+] Less [-]Side effects of spirotetramat on pupae and adults of a Neotropical strain of <em>Eretmocerus mundus</em> (Hymenoptera: Aphelinidae): Effects on the life parameters and demography
2017
Francesena, Natalia | Desneux, Nicolas | Ribeiro de Campos, Mateus | Schneider, Marcela Inés | Centro de Estudios Parasitologicos y de Vectores [La Plata] (CEPAVE) ; Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Universidad Nacional de la Plata [Argentine] (UNLP)-Comisión de Investigaciones Científicas [Buenos Aires] (CIC) | 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) | COMUE Université Côte d'Azur (2015-2019) (COMUE UCA) | PICT project from the Argentine National Agency for the Promotion of Science and Technology (ANPCyT) [1752]; PIP project from the Argentine National Agency for the Promotion of Science and Technology (ANPCyT) [0205]; CONICET
International audience | The negative impact of conventional pesticides on the environment is already extensively discussed worldwide. Although the use of chemical agents for controlling agricultural pests remains as first-line strategy for pest control, novel biorational active insecticides, such as spirotetramat, have appeared in the pesticide market during recent years in Argentina. The aim of this study was to assess the toxicity of spirotetramat on two developmental stages of a Neotropical strain of Eretmocerus mundus, with the conventional insecticide cypermethrin as a positive control, and to determine spirotetramat's side effects on parasitoid demographic parameters. Lethal effects of both insecticides on pupae and adults were evaluated by adult emergency and survival, respectively; whereas sublethal effects on both development stages were assessed by adult longevity, reproduction capacity, sex ratio, and longevity of the first progeny. Spirotetramat proved less harmful than cypermethrin at both developmental stages studied, corroborating once more the high toxicity of this pyrethroid to natural enemies. Although spirotetramat did not affect the emergence and reproductive capacity of adults surviving pupal exposure, the longevity of the first progeny was reduced as was adult survival and longevity after exposure to residues. Spirotetramat also reduced all demographic parameters in the population evaluation. This work is the first report of spirotetramat toxicity at the population level and demonstrates the need to assess the total effect of pesticides on natural enemies.
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