Devault, D. A., Beilvert, B., & Winterton, P. (2017). Ship breaking or scuttling? A review of environmental, economic and forensic issues for decision support. Environ. Sci. Pollut. Res., 24(33), 25741–25774.
Abstract: In a globalized world, the world trade fleet plays a pivotal role in limiting transport costs. But, the management of obsolete ships is an acute problem, with most Ship Recycling Facilities (SRF) situated in developing countries. They are renowned for their controversial work and safety conditions and their environmental impact. Paradoxically, dismantlement is paid for by the shipowners in accordance with international conventions therefore it is more profitable for them to sell off ships destined for scrapping. Scuttling, the alternative to scrapping, is assessed in the present review to compare the cost/benefit ratios of the two approaches. Although scrapping provides employment and raw materials – but with environmental, health and safety costs – scuttling provides fisheries and diving tourism opportunities but needs appropriate management to avoid organic and metal pollution, introduction of invasive species and exacerbation of coastal erosion. It is also limited by appropriate bottom depth, ship type and number. The present review inventories the environmental, health, safety, economic, and forensic aspects of each alternative. © 2016, Springer-Verlag Berlin Heidelberg.
Keywords: Artificial reef; Diving; Ship recycling; Ship Recycling Facilities; Shipbreaking; Tourism; Working conditions; Wrecks; artificial reef; coastal erosion; coastal zone management; cost-benefit analysis; decision support system; developing world; economic impact; environmental economics; environmental impact assessment; environmental issue; facility location; health and safety; invasive species; profitability; recycling; shipping; tourism; working conditions; wreck; analysis; decision support system; economics; international cooperation; pollution; prevention and control; procedures; recycling; ship; statistics and numerical data; Decision Support Techniques; Environmental Pollution; Internationality; Recycling; Ships
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Baudrimont, M., Arini, A., Guégan, C., Venel, Z., Gigault, J., Pedrono, B., et al. (2020). Ecotoxicity of polyethylene nanoplastics from the North Atlantic oceanic gyre on freshwater and marine organisms (microalgae and filter-feeding bivalves). Environ. Sci. Pollut. Res., 27(4), 3746–3755.
Abstract: Each year, 5 to 10 million tons of plastic waste is dumped in the oceans via freshwaters and accumulated in huge oceanic gyres. Under the effect of several abiotic factors, macro plastic wastes (or plastic wastes with macro sizes) are fractionated into microplastics (MP) and finally reach the nanometric size (nanoplastic NP). To reveal potential toxic impacts of these NPs, two microalgae, Scenedemus subspicatus (freshwater green algae), and Thalassiosira weissiflogii (marine diatom) were exposed for up to 48 h at 1, 10, 100, 1000, and 10,000 μg/L to reference polyethylene NPs (PER) or NPs made from polyethylene collected in the North Atlantic gyre (PEN, 7th continent expedition in 2015). Freshwater filter-feeding bivalves, Corbicula fluminea, were exposed to 1000 μg/L of PER and PEN for 48 h to study a possible modification of their filtration or digestion capacity. The results show that PER and PEN do not influence the cell growth of T. weissiflogii, but the PEN exposure causes growth inhibition of S. subspicatus for all exposure concentrations tested. This growth inhibition is enhanced for a higher concentration of PER or PEN (10,000 μg/L) in S. subspicatus. The marine diatom T. weissiflogii appears to be less impacted by plastic pollution than the green algae S. subspicatus for the exposure time. Exposure to NPs does not lead to any alteration of bivalve filtration; however, fecal and pseudo-fecal production increased after PEN exposure, suggesting the implementation of rejection mechanisms for inedible particles. © 2019, Springer-Verlag GmbH Germany, part of Springer Nature.
Keywords: Cordicula fluminea; Ecotoxicity; Nanoplastics; Polyethylene; Scenedesmus subspicatus; Thalassiosira weissiflogii; bivalve; concentration (composition); ecotoxicology; filter feeder; gyre; microalga; nanoparticle; plastic waste; pollution exposure; polymer; Atlantic Ocean; Atlantic Ocean (North); Bivalvia; Chlorophyta; Corbicula fluminea; Desmodesmus subspicatus; Nitzschia alba; Thalassiosira
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Prunier, J., Maurice, L., Perez, E., Gigault, J., Pierson Wickmann, A. - C., Davranche, M., et al. (2019). Trace metals in polyethylene debris from the North Atlantic subtropical gyre. Environ. Pollut., 245, 371–379.
Abstract: Plastic pollution in the marine environment poses threats to wildlife and habitats through varied mechanisms, among which are the transport and transfer to the food web of hazardous substances. Still, very little is known about the metal content of plastic debris and about sorption/desorption processes, especially with respect to weathering. In this study, plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals; as a comparison, new packaging materials were also analyzed. Both the new items and plastic debris showed very scattered concentrations. The new items contained significant amounts of trace metals introduced as additives, but globally, metal concentrations were higher in the plastic debris. The results provide evidence that enhanced metal concentrations increase with the plastic state of oxidation for some elements, such as As, Ti, Ni, and Cd. Transmission electron microscopy showed the presence of mineral particles on the surface of the plastic debris. This work demonstrates that marine plastic debris carries complex mixtures of heavy metals. Such materials not only behave as a source of metals resulting from intrinsic plastic additives but also are able to concentrate metals from ocean water as mineral nanoparticles or adsorbed species. Plastic debris collected from the North Atlantic subtropical gyre was analyzed for trace metals. Marine plastic debris carry complex mixtures of heavy metals but it is evidence that plastic oxidation favors their adsorption.
Keywords: metals'accumulation; Microplastic; Plastic debris; Polyethylene; Polymer
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Legeay, J., Husson, C., Boudier, B., Louisanna, E., Baraloto, C., Schimann, H., et al. (2020). Surprising low diversity of the plant pathogen Phytophthora in Amazonian forests. Environ. Microbiol., 22(12), 5019–5032.
Abstract: The genus Phytophthora represents a group of plant pathogens with broad global distribution. The majority of them cause the collar and root-rot of diverse plant species. Little is known about Phytophthora communities in forest ecosystems, especially in the Neotropical forests where natural enemies could maintain the huge plant diversity via negative density dependence. We characterized the diversity of soil-borne Phytophthora communities in the North French Guiana rainforest and investigated how they are structured by host identity and environmental factors. In this little-explored habitat, 250 soil cores were sampled from 10 plots hosting 10 different plant families across three forest environments (Terra Firme, Seasonally Flooded and White Sand). Phytophthora diversity was studied using a baiting approach and metabarcoding (High-Throughput Sequencing) on environmental DNA extracted from both soil samples and baiting-leaves. These three approaches revealed very similar communities, characterized by an unexpected low diversity of Phytophthora species, with the dominance of two cryptic species close to Phytophthora heveae. As expected, the Phytophthora community composition of the French Guiana rainforest was significantly impacted by the host plant family and environment. However, these plant pathogen communities are very small and are dominated by generalist species, questioning their potential roles as drivers of plant diversity in these Amazonian forests. © 2020 Society for Applied Microbiology and John Wiley & Sons Ltd.
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Leroy, C., Gril, E., Si Ouali, L., Coste, S., Gérard, B., Maillard, P., et al. (2019). Water and nutrient uptake capacity of leaf-absorbing trichomes vs. roots in epiphytic tank bromeliads. Environ. Exp. Bot., 163, 112–123.
Abstract: The water and nutrient uptake mechanisms used by vascular epiphytes have been the subject of a few studies. While leaf absorbing trichomes (LATs) are the main organ involved in resource uptake by bromeliads, little attention has been paid to the absorbing role of epiphytic bromeliad roots. This study investigates the water and nutrient uptake capacity of LATs vs. roots in two epiphytic tank bromeliads Aechmea aquilega and Lutheria splendens. The tank and/or the roots of bromeliads were watered, or not watered at all, in different treatments. We show that LATs and roots have different functions in resource uptake in the two species, which we mainly attributed to dissimilarities in carbon acquisition and growth traits (e.g., photosynthesis, relative growth rate, non-structural carbohydrates, malate), to water relation traits (e.g., water and osmotic potentials, relative water content, hydrenchyma thickness) and nutrient uptake (e.g., 15 N-labelling). While the roots of A. aquilega did contribute to water and nutrient uptake, the roots of L. splendens were less important than the role played by the LATs in resource uptake. We also provide evidenced for a synergistic effect of combined watering of tank and root in the Bromelioideae species. These results call for a more complex interpretation of LATs vs. roots in resource uptake in bromeliads. © 2019 Elsevier B.V.
Keywords: 15 N labelling; Carbon metabolism; Nutrient uptake; Plant performance; Tank bromeliad; Water status; Aechmea
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Sardans, J., Urbina, I., Grau, O., Asensio, D., Ogaya, R., & Peñuelas, J. (2020). Long-term drought decreases ecosystem C and nutrient storage in a Mediterranean holm oak forest. Environ. Exp. Bot., 177(104135).
Abstract: Aridity has increased in recent decades in the Mediterranean Basin and is projected to continue to increase in the coming decades. We studied the consequences of drought on the concentrations, stoichiometries and stocks of carbon (C), nitrogen (N), phosphorus (P) and potassium (K) in leaves, foliar litter of a three dominant woody species and soil of a Mediterranean montane holm oak forest where soil-water content was experimentally reduced (15 % lower than the control plots) for 15 years. Nitrogen stocks were lower in the drought plots than in the control plots (8.81 ± 1.01 kg ha−1 in the forest canopy and 856 ± 120 kg ha−1 in the 0−15 cm soil layer), thus representing 7 and 18 % lower N stocks in the canopy and soil respectively. δ15N was consistently higher under drought conditions in all samples, indicating a general loss of N. Foliar C and K stocks were also lower but to a lesser extent than N. Decreases in biomass and C and N stocks due to drought were smallest for the most dominant tall shrub, Phillyrea latifolia, so our results suggest a lower capacity of this forest to store C and nutrients but also substantial resulting changes in forest structure with increasing drought. © 2020 Elsevier B.V.
Keywords: Aridity; Carbon stocks; Climate change; Nitrogen; Phosphorus; Potassium; Stoichiometry; carbon sequestration; deciduous forest; drought; experimental study; forest soil; long-term change; Mediterranean environment; net ecosystem exchange; nutrient cycling; shrub; stoichiometry; Mediterranean Sea; Phillyrea latifolia
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Salhi, L., Nait-Rabah, O., Deyrat, C., & Roos, C. (2013). Numerical Modeling of Single Helical Pile Behavior under Compressive Loading in Sand. Electron. J. Geotech. Eng., 18(Bundle T), 4119–4338.
Abstract: The present research deals with helical piles behavior in cohesionless soil through finite element modeling. An approach of modeling of the screw-pile geometry has been proposed through the Finite Element Analysis (FEA) computer program Plaxis. The numerical results are compared with measurements from large scale test and the bearing capacity has been estimated using both cylindrical and individual bearing model. Moreover, different failure criterions have been applied to estimate the ultimate capacity. The effect of spacing ratio (S/Dh) on the screw-pile behavior has been further studied. It has found that results from the model fit the field results. Through the study of the load transfer mechanism, the transition from cylindrical shear to individual plate behavior occurs at a value of spacing ratio (1.5 to 2).
Keywords: helical pile; finite element method; failure mechanisms; sand
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Chevalier, M., Robert, F., Amusant, N., Traisnel, M., Roos, C., & Lebrini, M. (2014). Enhanced corrosion resistance of mild steel in 1 M hydrochloric acid solution by alkaloids extract from Aniba rosaeodora plant: Electrochemical, phytochemical and XPS studies. Electrochim Acta, 131, 96–105.
Abstract: The present report continues to focus on the broadening application of plant extracts for metallic corrosion control and reports on the inhibiting effect of the Aniba rosaeodora alkaloidic extract on the corrosion of C38 steel in 1 M hydrochloric acid. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of inhibitor. Studies on the phytochemical constituents were established to determine the active(s) molecule(s). XPS was also carried out to establish the mechanism of corrosion inhibition of the active molecule of C38 steel in acid solution. The inhibitor extract acted as an efficient corrosion inhibitor in 1 M HCl. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPEα, Q) has been used. Graphical methods are illustrated by synthetic data to determine the parameter of CPE (α, Q). Polarization studies showed that the Aniba rosaeodora alkaloidic extract was a mixed-type inhibitor and its inhibition efficiency increased with the inhibitor concentration. Studies on the phytochemical constituents of the total alkaloids extract shows that it contains the anibine as the major alkaloid. The results obtained from the electrochemical study have clearly showed that the inhibition efficiency of the total extract was due to the presence of anibine. The XPS studies showed the formation of inhibitor layer containing the Aniba rosaeodora alkaloidic extract and the anibine molecules. © 2014 Elsevier Ltd. All rights reserved.
Keywords: Acidic media; Adsorption-XPS; Aniba rosaeodora extract; Anibine; C38 steel; Corrosion inhibitor
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Suedile, F., Robert, F., Roos, C., & Lebrini, M. (2014). Corrosion inhibition of zinc by Mansoa alliacea plant extract in sodium chloride media: Extraction, Characterization and Electrochemical Studies. Electrochim Acta, 133, 631–638.
Abstract: Ethanol extract of Mansoa alliacea was tested as corrosion inhibitor for zinc in NaCl 3% media using polarization and electrochemical impedance spectroscopy (EIS). Potentiodynamic polarization curves indicated that the plant extract behaves as mixed-type inhibitor. Impedance measurements showed that there are two phenomena in the process of inhibition. The results obtained show that this plant extract could serve as an effective inhibitor for the corrosion of zinc in NaCl 3% media. The extract obtained give inhibition around 90%. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPEα,Q) has been used. Graphical methods are illustrated by synthetic data to determine the parameter of CPE (α, Q). Polarization curves show that Mansoa alliacea extract affects the anodic and cathodic reactions and the corrosion potential values were shifted to the positive potentials in the presence of the crude extract. Studies on the phytochemical constituents of the total extract were also established. Electrochemical studies, on the chemical families present in the crude extract, were also carried out to find the main constituents responsible for corrosion inhibition properties of the plant extract. © 2014 Elsevier Ltd.
Keywords: Corrosion; Inhibition; Mansoa alliacea; sodium chloride; zinc
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Tahiri, A., Amissa Adima, A., Adjé, F. A., & Amusant, N. (2011). Pesticide effects and screening of extracts of Azadirachta Indica (A.) Juss. on the Macrotermes bellicosus rambur termite. Effet pesticide et screening des extraits de Azadirachta indica (A.) Juss. sur le termite Macroterme, 65(310), 79–88.
Abstract: To recommend applications in the field of a naturally insecticide plant substance as an alternative to chemical control against termite attacks, several important prerequisites need to be satisfied to ensure its effectiveness. The toxicity, lethal dose, mode of action, persistence of insecticide effect and chemical composition of total aqueous, alcohol and hexane extracts of the leaves and seeds of the neem tree, Azadirachta indica, were tested with the Macrotermes bellicosus termite. The extracts were found to be highly toxic to termites on contact, killing the entire population tested. The insecticide effect of the extracts persisted from 2.4 to 4.2 days. The aqueous and hexane extracts were the most toxic (LD50 0.422±0.018 to 4,466±0,162 mg/l). Contact and inhalation were both essential to their effectiveness. The aqueous extract of seeds, which is the most active, is also capable of being transferred through the colony during social tasks. However, it seems to have an anti-appetent effect on termites and does not act by ingestion. It contains phenol compounds (tannins and flavonoids) and saponins. The hexane extract of seeds is oily and contains 11 fatty acids as well as terpenoids, flavonoids and saponins.
Keywords: Azadirachta indica; Pesticide properties; Phytochemical screening; Termite
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