Academic literature on the topic 'Contamination diffuse des sols'
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Journal articles on the topic "Contamination diffuse des sols":
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Tack, F. M. G., and B. Vandecasteele. "Metal Contaminated Dredged Sediment Derived Soils: A Case Of Diffuse Contamination." E3S Web of Conferences 1 (2013): 33009. http://dx.doi.org/10.1051/e3sconf/20130133009.
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Johnsen, Anders R., and Ulrich Karlson. "Diffuse PAH contamination of surface soils: environmental occurrence, bioavailability, and microbial degradation." Applied Microbiology and Biotechnology 76, no. 3 (June 27, 2007): 533–43. http://dx.doi.org/10.1007/s00253-007-1045-2.
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Meinardi, C. R., A. H. W. Beusen, M. J. S. Bollen, O. Klepper, and W. J. Willems. "Vulnerability to diffuse pollution and average nitrate contamination of european soils and groundwater." Water Science and Technology 31, no. 8 (April 1, 1995): 159–65. http://dx.doi.org/10.2166/wst.1995.0288.
Abstract:
From the Atlantic Ocean to the Ural Mountains, European soils are threatened by diffuse pollution from modern agriculture and increased atmospheric deposition. The vulnerability of the soil to diffuse pollution depends on land cover, topsoil features, net precipitation, aquifer type, groundwater recharge and age. The elaboration of the various elements was realized by applying Geographical Information Systems (GISs). Precipitation and the actual evapotranspiration were estimated using meteorological data. The resulting net precipitation is discharged by groundwater recharge and surfacial runoff, with the division of net precipitation in groundwater recharge and surfacial flow following from climate and soil features. The average groundwater age was based on aquifer depth, porosity and the recharge. The vulnerabilities of the soil and groundwater were estimated by establishing a ranking of the combined risks of a diffuse contamination for the topsoil and for groundwater in aquifers. Nitrogen compounds in soils are caused mainly by manuring and fertilization of agricultural lands and atmospheric deposition. The varying doses of fertilizer and manure and the atmospheric deposition of nitrogen compounds were assessed for an actual situation. Only part of the applied doses leached into the soil. The leaching of nitrate to a level of 1 m below land surface was estimated by applying empirical relations derived from the northwest European experience, based on land use, features of the topsoil and net precipitation. The subsequent leaching to deeper strata and a further denitrification also depend on groundwater recharge and aquifer type. The average nitrate concentration in the various aquifers was assessed by estimating the nitrogen doses to European soils in the course of time in combination with the groundwater age. Results, attained using GIS and presented in the form of maps, show the leaching of nitrate concentrations to a level of 1 m below land surface and also the average concentration in the upper aquifer system.
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Biasioli, Mattia, and Franco Ajmone-Marsan. "Organic and inorganic diffuse contamination in urban soils: the case of Torino (Italy)." Journal of Environmental Monitoring 9, no. 8 (2007): 862. http://dx.doi.org/10.1039/b705285e.
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Kabir, M. I., H. Lee, G. Kim, and T. Jun. "Monitoring and assessing heavy metals in topsoils as potential diffuse pollutants in the Pyeongchang River Basin, Korea." Water Science and Technology 61, no. 12 (June 1, 2010): 3156–61. http://dx.doi.org/10.2166/wst.2010.233.
Abstract:
Topsoils, mainly from crop fields, orchards, forests, and barns around the Pyeongchang River, were collected to investigate their heavy metal concentrations. Pollution load index, ecological risk index, and enrichment factor were applied to assess levels of heavy metal contamination for topsoils. The concentrations of cadmium (Cd) (1.7 mg/kg) and chromium (Cr) (4.1 mg/kg) exceeded the troublesome level in one site, whereas zinc (Zn) (396.7 to 711.1 mg/kg) and nickel (Ni) (40.1 to 95.3 mg/kg) in several topsoils exceeded the troublesome to countermeasure levels, according to soil contamination standards for the study areas. A significant risk of contamination was observed for mercury (Hg) by all indices, although the concentration in most of the topsoils was below the guideline. As expected, a positive linear correlation was observed for the values of pollution load index and ecological risk index, demonstrating lower heavy metal contamination in upstream areas compared to those downstream. High to extremely high ecological risk was observed in several samples for Zn and Ni, while all of the soils were unpolluted to slightly polluted, according to the pollution load index. A baseline study was not performed earlier for these sites, so these assessed values of heavy metals should be used as reference values for further assessment.
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Kookana, R. S., S. Baskaran, and R. Naidu. "Pesticide fate and behaviour in Australian soils in relation to contamination and management of soil and water: a review." Soil Research 36, no. 5 (1998): 715. http://dx.doi.org/10.1071/s97109.
Abstract:
Pesticides, if used as recommended, are generally expected to cause little adverse impact on the environment. However, it is evident that trace levels of pesticide residues present in soil, water, air, and sometimes food, may result in harmful effects on human and environmental health. Pesticides can pose health risks through several exposure pathways including direct occupational related exposure, through food, or through the residues present in the environment. This paper reviews available information on the nature and extent of pesticide contamination of Australian soils, surface water, and groundwaters. Published studies on the fate and behaviour of pesticides in Australian soils have also been reviewed, covering the key processes controlling the fate and behaviour of pesticides in soils, namely sorption-desorption, degradation (biological and abiotic), and volatilisation in soil and their off-site transport into surface and groundwaters. Some management options for minimising the diffuse source pollution of soils and waters by pesticides and remediation of contaminated soils and water have also been discussed. The review concludes that contamination of soils and water with pesticides has occurred in Australia and there is a need to understand the behaviour of pesticides in the soil environment in order to develop management practices to minimise any adverse impact on our environment in future.
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Kim, Nicholas D., Matthew D. Taylor, Jonathan Caldwell, Andrew Rumsby, Olivier Champeau, and Louis A. Tremblay. "Development and Deployment of a Framework to Prioritize Environmental Contamination Issues." Sustainability 12, no. 22 (November 11, 2020): 9393. http://dx.doi.org/10.3390/su12229393.
Abstract:
Management and regulatory agencies face a wide range of environmental issues globally. The challenge is to identify and select the issues to assist the allocation of research and policy resources to achieve maximum environmental gain. A framework was developed to prioritize environmental contamination issues in a sustainable management policy context using a nine-factor ranking model to rank the significance of diffuse sources of stressors. It focuses on contamination issues that involve large geographic scales (e.g., all pastoral soils), significant population exposures (e.g., urban air quality), and multiple outputs from same source on receiving environmental compartments comprising air, surface water, groundwater, and sediment. Factor scores are allocated using a scoring scale and weighted following defined rules. Results are ranked enabling the rational comparison of dissimilar and complex issues. Advantages of this model include flexibility, transparency, ability to prioritize new issues as they arise, and ability to identify which issues are comparatively trivial and which present a more serious challenge to sustainability policy goals. This model integrates well as a planning tool and has been used to inform regional policy development.
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Panagos, Panos, Cristiano Ballabio, Emanuele Lugato, Arwyn Jones, Pasquale Borrelli, Simone Scarpa, Alberto Orgiazzi, and Luca Montanarella. "Potential Sources of Anthropogenic Copper Inputs to European Agricultural Soils." Sustainability 10, no. 7 (July 9, 2018): 2380. http://dx.doi.org/10.3390/su10072380.
Abstract:
In the European Union (EU), copper concentration in agricultural soil stems from anthropogenic activities and natural sources (soil and geology). This manuscript reports a statistical comparison of copper concentrations at different levels of administrative units, with a focus on agricultural areas. Anthropogenic sources of diffuse copper contamination include fungicidal treatments, liquid manure (mainly from pigs), sewage sludge, atmospheric deposition, mining activities, local industrial contamination and particles from car brakes. Sales of fungicides in the EU are around 158,000 tonnes annually, a large proportion of which are copper based and used extensively in vineyards and orchards. Around 10 million tonnes of sewage sludge is treated annually in the EU, and 40% of this (which has a high copper content) is used as fertilizer in agriculture. In the EU, 150 million pigs consume more than 6.2 million tonnes of copper through additives in their feed, and most of their liquid manure ends up in agricultural soil. These three sources (sales of fungicides, sewage sludge and copper consumption for pigs feed) depend much on local traditional farming practices. Recent research towards replacing copper spraying in vineyards and policy developments on applying sewage and controlling the feed given to pigs are expected to reduce copper accumulation in agricultural soil.
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Dupuy, A., O. Banton, and M. Razack. "Contamination nitratée des eaux souterraines d'un bassin versant agricole hétérogène: 1. Évaluation des apports à la nappe (modèle Agriflux)." Revue des sciences de l'eau 10, no. 1 (April 12, 2005): 23–40. http://dx.doi.org/10.7202/705268ar.
Abstract:
Au cours des dernières décennies, la hausse de la productivité agricole s'est accompagnée d'une forte augmentation des fertilisations azotées qui a entraîné l'augmentation des concentrations en nitrates dans les eaux souterraines. Récemment, les études sur la gestion des pollutions diffuses agricoles ont intégré l'échelle du bassin versant hydrologique. Dans cet article, une approche basée sur un découpage en secteurs pédologiquement et agronomiquement homogènes a été élaborée pour permettre l'utilisation d'un modèle d'évaluation (AgriFlux), et obtenir les flux d'eau et de nitrates sortant de la zone racinaire sur l'ensemble d'un bassin. La modélisation du bassin de La Jannerie a porté sur une période de quatre ans impliquant 19 zones de simulation. L'influence du cycle végétatif des cultures et leur nature sur l'évolution des flux de nitrates a été mise en évidence par des simulations préliminaires, de même que l'influence du type de sol. L'évolution des concentrations moyennes saisonnières en nitrates sortant de la zone racinaire montre que les fertilisations minérales ne sont pas les seules sources importantes de nitrates dans les sols. Les pratiques culturales, comme le retournement des prairies, l'enfouissement des résidus de récoltes ou l'assolement, ont une forte influence sur la dynamique spatiale et temporelle des flux de nitrates percolant vers la nappe.
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Barbour, S. L., and N. Yang. "A review of the influence of clay–brine interactions on the geotechnical properties of Ca-montmorillonitic clayey soils from western Canada." Canadian Geotechnical Journal 30, no. 6 (December 1, 1993): 920–34. http://dx.doi.org/10.1139/t93-090.
Abstract:
Natural Ca-montmorillonite clay soils or engineered clay barriers in western Canada are often used to contain brine generated from the surface disposal of potash tailings or from drilling activities associated with the oil and gas industry. The performance of these barriers has ranged from excellent to poor. The influence of salt brines on the geotechnical properties of these soils has been recognized as a potentially important factor for some time. It has been well documented in the literature that the behavior of clayey soils is strongly influenced by physicochemical interactions between clay particles and pore-fluid chemistry; consequently, the properties of these soils are sensitive to changes in the electrolyte concentration of the pore fluid. An increase in the concentration of the pore fluid to the levels of a concentrated brine can cause significant changes in the geotechnical properties of the soil. In this paper, the impact of brine contamination on the geotechnical properties of two Ca-montmorillonitic clayey soils of glacial origin from western Canada is reviewed. The influence of clay–brine interactions on the index properties (liquid limit, plastic limit, plastic index, mineralogy, density, grain size, and compaction characteristics), mechanical properties (volume change and shear strength), and hydraulic properties (hydraulic conductivity) is described. A quantitative explanation for the changes that occur in the hydraulic and mechanical properties of these soils as a result of brine permeation is also provided. This explanation relates the changes in pore-fluid chemistry to changes in an effective physicochemical stress state. This approach may be used to predict the changes in hydraulic conductivity, volume, or shear strength of a clayey soil as a result of brine contamination. Key words : clay–brine interactions, diffuse double layer, hydraulic conductivity, soil structure, physicochemical.
Dissertations / Theses on the topic "Contamination diffuse des sols":
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Dupuy, Alain. "Simulation de la contamination diffuse des eaux souterraines par les nitrates à l'échelle du bassin versant." Poitiers, 1997. http://www.theses.fr/1997POIT2306.
Abstract:
La presente etude s'inscrit dans le cadre de recherches sur la gestion des pollutions diffuses agricole a l'echelle du bassin versant. Les sols et l'assolement observes sur un bassin versant pilote de poitou-charentes sont utilises dans un modele mecaniste stochastique agriflux pour simuler l'ecoulement de l'eau et le transport des nitrates dans la zone racinaire et dans la frange superieure de la zone non saturee sur une periode de 15 ans. Les resultats de cette sont utilises sous forme de flux saisonniers pour reconstituer les concentrations en nitrates rencontrees dans la nappe. Une approche basee sur un modele de melange a montre que l'on pouvait reconstituer les concentrations de nitrates dans la nappe en fonction des conditions hydrodynamiques et des flux d'eau et de nitrates percolant depuis la surface. Dans une seconde approche, le couplage hydrodynamique entre les differentes zones du milieu (racinaire, non saturee et saturee) est realise sur des modeles d'ecoulement et de transport adaptes a l'echelle du bassin versant. Les flux d'infiltration calcules par agriflux dans la zone non saturee sont utilises comme flux de recharge dans le modele hydrodynamique modflow qui est utilise pour simuler l'hydrodynamique transitoire sur l'ensemble du bassin. Les periodes de contraintes de 90 jours sont determinees a l'aide d'une analyse correlatoire sur les donnees pluviometrique et piezometrique, et permettent de reconstituer un pseudo-regime transitoire par une succession d'etats permanents. Le modele mt3d est utilise pour la simulation du transport des nitrates dans la nappe avec le meme decoupage temporel que celui de modflow. L'hydrodynamique et le transport sont reconstitues sur le bassin sur une periode de 15 ans avec un pas de temps saisonnier. La dynamique des teneurs en nitrates dans une nappe a l'echelle d'un bassin versant et l'impact de differentes pratiques culturales peuvent ainsi etre simules dans une optique de gestion des pollutions diffuses agricoles.
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Hullot, Olivier. "Approche d'écotoxicologie fonctionnelle par l'étude des interactions sol-plante-annélides en sol contaminé." Electronic Thesis or Diss., université Paris-Saclay, 2023. http://www.theses.fr/2023UPASB012.
Abstract:
La contamination des sols est un enjeu environnemental majeur. Une grande partie des sols contaminés en Europe le sont par des éléments traces métalliques. Celle-ci peut affecter les organismes édaphiques, avec souvent comme conséquence une diminution des activités biologiques. Pourtant plusieurs études ont montré l’importance des relations dites « belowground-aboveground » liant les communautés souterraines et aériennes des sols. Parmi elles, l’une des plus connues est l’interaction sol – plante – ver de terre. Ces derniers sont connus pour impacter positivement les fonctions écologiques des sols non contaminés. En effet, ils peuvent augmenter la production primaire des plantes et jouent également un rôle dans la régulation des communautés du sol. Mais dans le cas de sols contaminés, leur rôle reste encore peu documenté. Les enchytréides sont également des annélides oligochètes auxquels on prête le même rôle écologique que les vers de terre. Toutefois, peu d’études permettent d’appuyer cette hypothèse.Dans ce travail nous avons fait l’hypothèse que les connaissances acquises sur les interactions sol – plante – annélides en sol fertile sont transférables en sols contaminés et donc que les annélides peuvent, en interaction avec les plantes, participer à une valorisation de ces sols. Les questions suivantes ont été soulevées : i) y-a-t 'il des modifications de biodisponibilité des contaminants par l’activité des organismes ? Quel est l’impact réciproque des organismes entre eux ? Peut-on mettre en évidence un effet court terme versus long terme sur plusieurs générations de vers ? Pour répondre à ces questions nous avons fait des expérimentations ex situ. Nous avons utilisé un sol considéré comme marginal par sa texture sableuse, et contaminé in situ par plusieurs éléments traces métalliques (teneurs sublétales en Cu, Zn, Cd). Trois espèces biologiques ont été étudiées seules ou en interaction : le ver de terre Aporrectodea caliginosa, un ver de terre endogé communément retrouvé dans les sols agricoles, Enchytraeus albidus, un enchytréide à large habitat approprié pour les tests écotoxicologiques et enfin Lolium perenne, une herbe fourragère.Nous avons montré une amélioration de la production primaire du sol contaminé par les deux groupes d’annélides, via une amélioration de la biomasse des plantes, lorsqu’il y a une interaction proche entre les racines et les annélides, en lien avec une augmentation de la biodisponibilité des nutriments. Cependant, lorsqu’ils s’éloignent des racines, cet effet bénéfique disparait. Concernant les éléments traces, les annélides du sol tendent à augmenter leur disponibilité. Toutefois, la plante possède un pouvoir fort de régulation limitant les transferts d’éléments trace. Les teneurs internes d'éléments mesurées dans les organismes varient d’un élément à l’autre et d’une espèce biologique à l’autre, ainsi qu’en présence d’interactions entre organismes. Nous avons ainsi pu montrer que les modifications de l’environnement induites affectent tous les organismes. Nous avons notamment montré que la présence de plantes sur le long terme augmente la capacité du sol à les héberger même en sol contaminé. En revanche, la présence de vers de terre dans le sol facilite l’enfouissement des enchytréides dans les couches plus profondes du sol et tend à réduire leur nombre retrouvé en surface. Cette étude montre que dans nos conditions expérimentales les connaissances acquises dans les sols non contaminés concernant la biofertilisation peuvent être appliquées aux sols contaminés. Cependant, les flux d’éléments majeurs s’accompagnant de flux d’éléments traces, l’impact résultant doit être examiné dans tous les compartiments biologiques du système. Nous avons de plus observé des effets de rétroactions de la plante sur les vers de terre, suggérant l’importance de les prendre en compte pour avancer dans la compréhension des mécanismes sous-jacents aux interactions sol-plante-annélidesSoil pollution is key environmental issue. A large part of European soils is contaminated by trace elements. Depending on the contamination level organisms exposed to degraded and contaminated soils can be affected in a variety of ways but generally contamination affects the biological activity. However, several researches have shown the importance of ecological linkages in soils, particularly the so-called "belowground-aboveground" relationships that connect the below-ground and above-ground soil communities. One of the most well-known of these relationships is the soil-plant-earthworm interactions. Earthworms are known to improve the ecological functions associated with fertile soils. For example, they can increase the primary production of both wild and cultivated plants and at the same time they have a key role in regulating soil communities. But in the case of contaminated soil their role is still poorly documented. Enchytraeids are oligochaete annelids that play the same ecological role as earthworms. However, there are few researches that confirm this hypothesis, whatever the soil contaminated or not. In this work, we hypothesised that the knowledge gained on soil-plant-annelid interactions in non-contaminated soils are transferable to polluted soils. In this case, annelids in interaction with plants could participate to the valorisation of these soils. We raised several questions: Do activities of annelids in contaminated soils affect the bioavailability of trace elements? Is there a reciprocity of influence between the soil organisms or plants? Are the annelids effects on the short or the long-term following several annelid life cycles? To answer these questions, we performed ex-situ experiments in cosmes. We used a soil classified as marginal because of its sandy texture, and field contaminated by several metallic trace elements (sublethal contents in Cu, Zn, Cd). Three different biological species were studied, alone or in interaction: Aporrectodea caliginosa, an endogeic earthworm found in agricultural soils, Enchytraeus albidus, an enchytraeid with a large habitat suitable for ecotoxicological testing, and finally Lolium perenne, a forage grass.We have seen an increase in the primary output of the contaminated soil via an increase in plant biomass, when a close connection between the roots and the annelids was assessed. We also showed that both annelid species have the ability to increase biomass production. However, when they move away from the roots, this positive effect decreases. This favourable effect on plants is due to an increase in nutrient bioavailability, linked to the annelid activities. However, annelids also tend to increase trace metal fluxes, and then their environmental availability with high contents in soil solution. But the plant has in turn a powerful regulatory power that limits metal transfers to the soil pore water. Furthermore, the trace element values observed in organisms differ from one chemical species to the other, as well as from one biological species to the other. Finally, the presence of species and the changes in their habitat have an impact on other organisms. We have shown that the presence of plants is favourable to the development of earthworms, boosting the soil's capacity to host them over time. The presence of earthworms in the soil, on the other hand, accelerates the burial of enchytraeids in the deeper layers of the soil and tends to diminish the amount of enchytraeids detected in soil surface. In our experimental conditions, we confirm that knowledge acquired for uncontaminated soils can be applied also for contaminated soils. However, fluxes of major elements are accompanied by fluxes of trace elements whose impact have to be checked in all the biological compartments of the system. Finally, we detected feedback from the plant to the earthworms, indicating intricate soil-plant-annelid connections that has to be taken into account for their better understanding
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VIEIRA, Leidivam Pereira. "Acumulação de nutrientes e metais pesados em solo, água e hortaliças em áreas cultivadas com olerícolas no Agreste de Pernambuco." Universidade Federal Rural de Pernambuco, 2011. http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/5192.
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Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq
Increasing world population elevates the demand for food. Then, it's a constant challenge to ensure food with quantity and quality appropriate. The management of soil fertility using fertilizers and controlling pests and weeds are necessary strategies for maintaining or increasing agricultural production. Agrochemicals are anthropogenic sources potentially polluting the environment, both the defensive as the mineral and organic fertilizers and agricultural lime, may contain heavy metals such as impurities in their composition. The horticulture stands out as an activity that uses many inputs, with frequent application of pesticides and fertilizers. Thus this study aimed to determine the concentrations of nutrients and heavy metals in soils, water sources and vegetables in areas under different land uses in the Sao Felix Camocim city, Pernambuco State, Brasil, evaluating the risk of environmental contamination. Soil samples were collected in the rows in the upper, middle and bottom of the hill farming areas, and in the forest areas, at three depths (0-10, 10-30 and 30-60 cm). Monthly, were collected 200 mL of water dams that supply the area under cultivation, and plant samples of Tomato, Eggplant, Pepper, Zucchini and Chard. Variables were subjected to analysis of variance and Tukey test at 5% probability level. Applied the t test ( P < 0,05) for medium aiming paired comparisons between content of heavy metals in cultivated areas and forest, besides Pearson correlations (P<0,05; 0,01). The fertility of soils resulting from cultivation with vegetables has changed in relation to forest areas (reference).The management of the phosphate fertilizations in areas cultivade with vegetables caused increase in levels of available P in the soil, causing pollution of water bodies water (dams); The levels of NPK and pH of the water dams was influenced by rainfall, with reduction of soil pH and P levels, and increasing concentrations of NO32- and K, The phosphate fertilization appeared to be the main entry of Cd in the soil as a contaminant of fertilizers, and was found accumulation of Cd, Cu, Mn and Zn in the first depth of soil.Rainfall had a greater influence on the concentration of Pb and moderate influence on concentrations of Cd and Ni was not detected the presence of Cu, Mn and Zn in surface water and in the well.
Com o aumento da população mundial cresce também a demanda por alimentos. Por isso é um desafio constante garantir alimentos em quantidade e qualidade adequadas a toda esta população. O manejo do solo através da fertilização e o controle de pragas e ervas daninha são estratégias necessárias para a manutenção ou aumento da produção agrícola. Os agroquímicos são fontes antropogênicas potencialmente poluidoras do ambiente, tanto os defensivos quanto os fertilizantes minerais e orgânicos e corretivos agrícolas, podem conter metais pesados, como impurezas, na sua composição. A olericultura destaca-se como atividade que utiliza muitos insumos, com aplicação frequente de agrotóxicos e fertilizantes. Assim esta pesquisa teve por objetivo determinar as concentrações de nutrientes e metais pesados em solos, fontes de água e hortaliças em áreas sob diferentes usos no município de Camocim de São Félix, avaliando o risco de contaminação ambiental. Os solos foram coletados nas linhas de plantio, nos terços superior, médio e inferior da encosta nas áreas cultivadas, e em ziguezague nas áreas de mata, em três profundidades (0-10, 10-30 e 30-60 cm). Coletou-se mensalmente 200 mL de água das barragens que abastecem as áreas de cultivo, além de amostras de tomate, berinjela, pimentão, abobrinha e acelga. As variáveis foram submetidas à análise da variância e teste de Tukey a 5% de probabilidade para comparação entre os tratamentos. Aplicou-se o teste t (5%) para médias pareadas visando comparações entre os teores de nutrientes e metais pesado em áreas cultivadas e de mata, além de correlações de Pearson a 1% e 5% entre as variáveis. Constatou-se que a fertilidade dos solos decorrente dos cultivos com olerícolas foi alterada em relação às áreas de referência. O manejo adotado quanto às fertilizações fosfatadas nas áreas produtoras de olerícolas promoveu aumento substancial nos teores de P disponível no solo, provocando contaminação dos corpos d’água (barragens); Os teores de NPK e o pH das águas das barragens sofreram influência direta da precipitação pluviométrica, com redução do pH e dos teores de P, e aumento dos teores de NO32- e K, com o aumento da precipitação. As fertilizações fosfatadas pareceram ser a principal via de entrada do Cd no sistema solo como contaminante desses fertilizantes, bem como ocorreu acúmulo superficial de Cd, Cu, Mn e Zn no solo. A precipitação pluviométrica exerceu maior influência na concentração de Pb e influência moderada nas concentrações de Cd e Ni, não sendo detectada a presença de Cu, Mn e Zn nas águas superficiais e do poço.
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Nouhou, Bako Amina. "Modélisation numérique de l’érosion diffuse des sols : interaction gouttes-ruissellement." Thesis, Orléans, 2016. http://www.theses.fr/2016ORLE2027/document.
Abstract:
L’objectif de cette thèse est de proposer un modèle d’érosion diffuse qui intègre les principaux processus de ce phénomène (détachement, transport, sédimentation) et qui prend en compte l’interaction des gouttes de pluie avec ces processus. Dans un premier temps, nous avons établi une loi de détachement par la pluie qui inclut l’effet des gouttes et celui de l’épaisseur de la lame d’eau qui couvre la surface du sol. Pour obtenir cette loi, une étude numérique avec le logiciel Gerris a permis de modéliser les cisaillements créés par l’impact des gouttes sur des épaisseurs de lame d’eau variables. Ces cisaillements estiment la quantité de sol détaché par chaque goutte. Nous avons montré, à travers une étude probabiliste, que les gouttes sont quasiment indépendantes lors du détachement. Les détachements de l’ensemble des gouttes sont donc sommés pour établir la loi de détachement pour la pluie. Par ailleurs, l’étude probabiliste a montré la possibilité d’une forte interaction entre les gouttes de pluie et les particules en sédimentation. Par conséquent, pour le processus de transport-sédimentation, nous avons privilégié une approche expérimentale. Cette étude a révélé que l’effet des gouttes de pluie est d’augmenter la vitesse de sédimentation des particules. Enfin, nous avons proposé un nouveau modèle d’érosion qui généralise plusieurs modèles d’érosion de la littérature et décrit l’évolution des concentrations en sédiments avec des effets linéaires et non-linéaires. Selon le choix des paramètres du modèle, celui-ci peut représenter l’érosion diffuse et concentrée à l’échelle du bassin versant, le transport par charriage dans les rivières ou encore le transport chimique. L’intégration du modèle dans le logiciel de ruissellement FullSWOF est aussi réaliséeThe aim of this work is to formulate an interrill erosion model. This model should take into account the main erosion processes (detachment, transport and sedimentation) and the interaction of raindrops during these processes. First we develop a law for rainfall detachment that includes the effects of the raindrops and the water layer thickness at the soil surface. We use the Gerris software to simulate the shear stresses created by the impacts of raindrops at the soil surface. These shear stresses allow to evaluate the quantity of soil detached by each raindrop. We have shown with a probabilistic approach that raindrops are almost independent during soil detachment. Then by summing all the raindrops detachments we obtain the rainfall detachment law. Futhermore the probabilistic study has revealed the possibility of a strong interaction between raindrops and settling particles. So, we used specific laboratory experiments to investigate the particles transport and sedimentation processes. These experiments show that the effect of raindrops is to increase the particles settling velocity. Finally, we propose a new erosion model which encompasses previous literature erosion models and that can describe the behavior of sediments concentrations with linear and non-linear behaviors. The model is able to simulate interrill and rill erosions at the watershed scale, bedload transport in rivers and chemical transfer. The integration of the model in the FullSWOF runoff software is also carried out
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Casquin, Antoine Philippe. "Fatores determinantes da qualidade da água na Bacia Hidrográfica do Rio Preto (MG/RJ)." Universidade Federal de Juiz de Fora (UFJF), 2016. https://repositorio.ufjf.br/jspui/handle/ufjf/5647.
Abstract:
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CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
A Bacia Hidrográfica do rio Preto (BHRP) é uma bacia estratégica por representar 15% em superfície da bacia hidrográfica do rio Paraíba do Sul. A BHRP também é um território onde vivem 700.000 habitantes, sendo mais de 500.000 concentrados na área urbana de Juiz de Fora. As pequenas cidades e as florestas muito fragmentadas se destacam no meio das pastagens que dominam a paisagem. Os solos são em geral pobres e susceptíveis a erosão, além das declividades acentuadas. A qualidade da água é alterada por fontes pontuais (indústrias, lixões, aterros, incineradores) e fontes difusas mais difíceis de identificar. Essa pesquisa teve como objetivo relacionar a qualidade da água na BHRP com fatores físicos (relevo, solos, morfometria e pluviometria) e antrópicos (uso e cobertura da terra e densidade de população). Esses fatores foram quantificados com o emprego do Geoprocessamento para as 17 sub-bacias da BHRP, cobrindo seus quatros rios principais: rio Preto, rio do Peixe, rio Paraibuna e rio Cágado. Essas sub-bacias correspondem aos pontos de monitoramento de qualidade da água do IGAM. A evolução espacial da qualidade da água do Eixo Paraibuna-Peixe-Preto foi avaliada ao atravessar a área urbana de Juiz de Fora e ao ser diluída a jusante pelos rios principais dessa Bacia. Essa primeira etapa permitiu determinar que os parâmetros OD e DBO foram os mais impactados pela área urbana de Juiz de Fora e que os parâmetros Ferro Dissolvido, Manganês Total, Fósforo Total e Escherechia Coli sofriam alterações crónicas na globalidade da BHRP, classificando assim a suas águas como incompatíveis com os usos pretendidos. Contaminações com metais (cádmio, chumbo e zinco) foram detectadas a montante e a jusante de Juiz de Fora, indicando o impacto pontual de indústrias nesses parâmetros. Correlações não paramétricas foram calculadas entre os fatores e as variáveis. Observou-se uma grande interdependência dos fatores físicos e antrópicos. A análise das correlações entre os fatores e as variáveis de qualidade da água apontou que o uso e cobertura da terra foi o fator mais determinante da qualidade da água da BHRP. Concentrações altas de manganês, de chumbo e de cianetos livres foram encontradas na BHRP sem explicação pelas características das suas sub-bacias. A classe “área urbana densa” piorou quase todos os parâmetros e a classe “vegetação arbórea e arbustiva” melhorou em quase todos. A classe “vegetação rasteira” piorou os parâmetros relativos a contaminação fecal e os nutrientes, sobretudo na estação chuvosa. Esses resultados indicam que as contaminações pontuais e difusas da água devem ser investigadas e fiscalizadas com mais efetividade na BHRP, com destaque para a difusa, e que, no mínimo, as leis de preservação e proteção dos recursos hídricos devem ser aplicadas.
Le bassin hydrographique du la rivière Preto (BHRP) est un bassin stratégique représentant 15% de la surface du bassin hydrographique de la rivière Paraíba do Sul. La BHRP est aussi un territoire où vivent 700.000 habitants, dont plus de 500 000 concentrés dans la zone urbaine de Juiz de Fora. De petites villes et des fragments de forêts au milieu de vastes pâturages composent le paysage. Les sols sont généralement pauvres et sensibles à l'érosion, en plus des pentes raides. La qualité de l'eau est altérée par des sources ponctuelles (industries, décharges, incinérateur) et des sources diffuses plus difficiles à identifier. Cette étude a eu pour objectif de relier la qualité de l'eau dans BHRP à des facteurs physiques (topographie, sols, morphométries et précipitations) et anthropiques (occupation et utilisation du sol et densité de population). Ces facteurs ont été déterminés à travers l’utilisation de la géomatique pour les 17 sous-bassins de la BHRP couvrant ses quatre principaux fleuves : le rio Preto, le rio do Peixe, le rio Paraibuna et le rio Cágado. Ces sous-bassins correspondent aux points de contrôle de la qualité de l’eau de IGAM (Institut de Gestion des Eaux du Minas Gerais). L'évolution spatiale de la qualité de l’eau suivant un axe Paraibuna-Peixe-Preto a été étudiée de la traversée de la zone urbaine de Juiz de Fora et jusqu’aux dilutions en aval par les principales rivières de ce bassin. Cette première étape a permis de déterminer que les paramètres OD et de DBO ont été les plus touchés par la zone urbaine de Juiz de Fora et que les paramètres « fer dissous », « manganèse total », « phosphore total » et « Escherechia Coli » subissent des altérations chroniques dans la globalité de la BHRP, classifiant ainsi ses eaux comme incompatibles avec l'utilisation prévue par la législation. Des contaminations aux métaux (cadmium, plomb et zinc) ont été détectées en amont et en aval de Juiz de Fora, indiquant l’impact ponctuel des industries. Des corrélations non paramétriques ont été calculées entre les caractéristiques naturels et anthropiques des sousbassins (facteurs) et les paramètres de qualité de l’eau. Une grande interdépendance des facteurs physiques et humains a été constatée. L'analyse des corrélations entre les facteurs et les paramètres de la qualité de l'eau a montré occupation et utilisation du sol a été le facteur le plus déterminant de la qualité de l’eau de la BHRP. Des concentrations élevées de manganèse, de plomb et de cyanure libre ont été trouvés dans BHRP sans pouvoir être expliqués par les caractéristiques de leurs sous-bassins. La classe «aire urbaine dense" a empiré presque tous les paramètres et la classe "végétation arborée ou arbustive" classe les a presque tous améliorée. La classe "pâturage" a empiré les paramètres relatifs à la contamination fécale et augmenté les concentrations de macronutriments (azote et phosphore), en particulier pendant la saison des pluies. Ces résultats indiquent que la contamination ponctuelle et particulièrement la contamination diffuse de l'eau doit être étudiée et surveillée de manière plus efficace dans la BHRP, et qu'au minimum, les lois de conservation et de protection des ressources hydriques doivent être appliquées.
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O'Shea, Francis Timothy. "Assessment of diffuse pollution originating from estuarine historical landfills." Thesis, Queen Mary, University of London, 2016. http://qmro.qmul.ac.uk/xmlui/handle/123456789/12995.
Abstract:
The UK contains 5000 unlined historical landfills in the coastal zone currently at risk of erosion within the next 50 years. These rely on natural attenuation in surrounding sediment to reduce the contaminant load to the environment. This thesis investigates the extent and magnitude of sediment metal contamination from historical estuarine landfills. An intensive investigation of Newlands historical landfill, Essex, indicated elevated metal concentrations in surface and sub-surface sediments. Surface sediment concentrations were similar to other industrially impacted estuaries, whilst peak metal concentrations at c. 50 cm depth were indicative of industrial activity in the mid-20th Century. Below this depth, sediments were enriched with Pb (EF > 2) and Zn (EF = 1.5) indicative of an historic leachate plume that extends c. 15 m from the landfill site boundary. These sediments present a secondary source of diffuse pollution and a site contamination load of c. 1200 kg Pb. In-situ XRF was demonstrated as a rapid contamination screening tool for Fe, Pb, Sr and Zn enabling a broad-scale investigation of historical landfills across SE England. Sediment cores from eight sites containing both hazardous and inert waste were screened. Concentrations and EFs of Pb and Zn at depth were significantly higher in hazardous sites compared to inert sites. Spatial distributions of Pb and Zn were comparable to Newlands historical landfill. This indicates that diffuse pollution from historical landfill sites with similar chemical and physical attributes to Newlands is likely to present a regional, if not national problem, with UK historical landfills presenting contaminated sediments, comprising a significant, previously unidentified and unquantified diffuse pollution source in the coastal zone.
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Dubé, Jean-Sébastien. "Modifications hydrodynamiques du comportement des métaux lourds dans un sol hétérogène présentant une contamination résiduelle en NAPL : étude sur la contamination mixte des sols." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ65448.pdf.
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Buco, Stéphanie. "Métrologie de la contamination des sols par les hydrocarbures aromatiques polycycliques." Aix-Marseille 3, 2001. http://www.theses.fr/2001AIX30098.
Abstract:
Les Hydrocarbures Aromatiques Polycycliques (HAP), reconnus comme polluants prioritaires en raison de leurs propriétés mutagènes et cancérigènes, ont suscité le développement de nombreuses techniques analytiques de terrain ou de laboratoire. Les techniques in situ sont utilisées pour un criblage de la pollution et peuvent être complétées par des analyses de laboratoire qui apportent une connaissance précise de la contamination. Notre travail était de développer de nouvelles méthodes en minimisant les inconvénients de ces deux approches analytiques qui sont pour la première, une faible précision des résultats et pour la seconde un temps et un coût d'analyse élevés. L'étude réalisée en laboratoire montre que la pyrolyse à point de Curie couplée à la chromatographie gazeuse et spectrométrie de masse (Cpp-CG/SM) est une méthode alternative efficace pour l'analyse des HAP. Elle permet d'obtenir des résultats au moins similaires à ceux des techniques classiques dans un court intervalle de temps et sans consommation de solvant. .The Polycyclic Aromatic Hydrocarbons (PAHs) are proven to be major pollutants because of their mutagenic and carcinogenic properties. These compounds raised up many "on-site" or laboratory methods developments. The in situ methods are used for a rapid screening of contaminated soils and can be completed by laboratory analyses to give more accuracy. The aim of this study was to develop new methods with the minimization of the "on-site" and laboratory methods drawbacks which are respectively low accuracy, cost and analysis time. It appears from our laboratory study that the Curie-point pyrolysis-gas chromatography/mass spectrometry (Cpp-GC/MS) is an efficient alternative method for the PAHs determination. We obtained similar results compared to classical methods, with short operating time and without solvent consumption. The in situ methodology is based on a "on-site" extractor, developed during this work and UV spectrophotometric measurements (Pastel-UV). This methodology has proved to be a fast, quantitative and qualitative screening of contaminated soils by PAHs. The results show that our "on-site" extractor is more efficient than the usual "hand shaking" methods. A correlation was established between laboratory and "on-site" results to near to real PAHs concentration
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Robiolle, Céline. "Caractérisation de complexants naturels actifs dans l'accumulation du césium dans les champignons." Université Louis Pasteur (Strasbourg) (1971-2008), 2002. http://www.theses.fr/2002STR13176.
Abstract:
L'objectif principal de cette thèse était d'améliorer la compréhension des bases moléculaires de l'accumulation du (radio)césium chez certains champignons supérieurs. Tout d'abord, l'évaluation de facteurs de transfert sol-champignon de métaux pour quelques espèces comestibles a mis en évidence une grande variabilité inter et intra-spécifique pour les éléments non essentiels. En particulier, le prélèvement du césium apparaît lié à celui du potassium, particulièrement actif dans les sols appauvris en cet élément. Les aspects moléculaires de la complexation du césium ont ensuite été abordés par l'étude physico-chimique de la norbadione A, un pigment présent dans le Bolet bai. Cette étude a permis de déterminer les constantes de protonation de la norbadione A ainsi que les constantes de stabilité de complexes de césium mono et dinucléaires. Ce pigment présente une coopérativité positive vis-à-vis de l'incorporation du deuxième atome de césium, ce qui permet d'expliquer, au moins en partie, l'aptitude montrée par le Bolet bai à concentrer le radiocésium. Enfin, la recherche de nouvelles molécules chélatant les métaux a été entreprise dans la Pholiote ridée et dans la Langue-de-bœuf. Aucun complexe spécifique du césium n'a pu être mis en évidence dans la Pholiote ridée, mais plusieurs composés quantitativement importants ont pu être caractérisés (triglycérides, stéroi͏̈des, diol, a,a-tréhalose). L'isolement et l'identification partielle de pigments de la Langue-de-bœuf ont mis en évidence l'existence de structures originales susceptibles de présenter des propriétés chélatantes intéressantesThe main aim of this study was to improve the molecular ground understanding of the radiocaesium accumulation in higher fungi. First, the determination of soil-to-mushroom transfer factors of metals for some edible species highlighted a large variability in non-essential element uptake. Thus, caesium uptake appears to be linked to that of potassium, particularly efficient in K-depleted soils. Second, the physico-chemical study of norbadion A, the major pigment of Xerocomus badius, allowed the protonation constants and the stability constants for mononuclear and dinuclear caesium complexes to be determined. Positively cooperative interactions between the two caesium in the dinuclear complex are in line with the ability of norbadion A to store radiocaesium in bay boletus. Thirdly, the research of new metal-chelating molecules in Rozites caperatus and Fistulina hepatica was undertaken. No caesium-specific complex could be detected in Rozites caperatus, in which, however, several quantitatively important compounds were characterised (triglycerides, steroids, diol, ?,?-tréhalose). Partial identification of pigments isolated from Fistulina hepatica discloses the presence of novel structures able to show interesting chelating properties
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Abdul, Rida Abdul Motalibe Mohammad. "Biosurveillance de la contamination du sol : apport de l'étude des lombriciens à l'évaluation des risques liés aus éléments traces." Montpellier 2, 1992. http://www.theses.fr/1992MON20124.
Abstract:
L'objectif du travail a ete d'evaluer les risques ecologiques resultant des teneurs des sols en 5 elements traces (cd, cu, ni, pb et zn). Ces elements ont deux origines: geologiques et anthropogenetiques. Ce travail a ete realise a partir de 186 points d'etude repartis dans 6 sites au sud de la france. Les sols etudies ont des proprietes physicochimiques tres variees. L'etude montre d'une part la possibilite d'effectuer une biosurveillance directe (sur le terrain) de la contamination par les elements traces des milieux terrestres et d'autre part l'interet d'utiliser les lombriciens comme outils de mesure et de comparaison des niveaux de bio-contamination (bio-indication physiologique). Cette bioconcentration depend de la teneur totale en elements traces des sols mais aussi des proprietes physicochimiques et des categories ecologiques lombriciennes. Partant de ces bioconcentrations de contaminants observes, il a ete possible de faire une evaluation des transferts importants des contaminants depuis les lombriciens vers leurs predateurs, ceux-ci se sont averes preoccupants. En outre, nous avons constate la disparition (bio-indication existentielle), dans des sols contamines par les elements traces, d'un genre lombricien anecique (scherothe ca spp. ) important dans le fonctionnement d'ecosystemes (erosion, chaines alimentaires, degradation de la matiere organique et liberation des elements necessaires aux plantes et aux microorganismes. . . ). L'etude a montre egalement que les analyses partielles et les etudes en microcosmes contribuent peu a la connaissance ecotoxicologique
Books on the topic "Contamination diffuse des sols":
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Laurent, Claire. Contamination des sols: Transferts des sols ver les animaux. Les Ulis: EDP Science, 2005.
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Laurent, Claire. Contamination des sols: Transferts des sols vers les animaux. Les Ulis [France]: EDP Sciences, 2005.
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Feix, Isabelle. Contamination des sols: Transferts des sols vers les plantes. Les Ulis: EDP Science, 2005.
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MacDonald, K. Bruce. Indicator of risk of water contamination: Nitrogen component. Ottawa: Agriculture and Agri-Food Canada, 1996.
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Reynolds, W. D. Methodology for predicting agrochemical contamination of ground water resources. [Ottawa]: Research Branch, Agriculture and Agri-Food Canada, 1994.
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Bossche, Hugues Vanden. Devenir du phosphore apporté sur les sols et risques de contamination des eaux de surface: Cas des boues de stations d'épuration. Rennes, France: Géosciences Rennes, UMR 6118, CNRS-Université de Rennes I, Campus de Beaulieu, 2002.
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Asrari, Elham. Heavy metal contamination of water and soil: Analysis, assessment, and remediation strategies. Toronto: Apple Academic Press, 2014.
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Boulding, Russell. Practical handbook of soil, vadose zone, and ground-water contamination: Assessment, prevention, and remediation. Boca Raton: Lewis Publishers, 1995.
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Boulding, Russell. Practical handbook of soil, vadose zone, and ground-water contamination: Assessment, prevention, and remediation. 2nd ed. Boca Raton, Fla: Lewis Publishers, 2004.
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Feix, Isabelle, and Anne Tremel-Schaub. Contamination des sols. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0261-6.
Book chapters on the topic "Contamination diffuse des sols":
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Giandon, Paolo. "Soil Contamination by Diffuse Inputs." In Environmental Indicators, 331–41. Dordrecht: Springer Netherlands, 2014. http://dx.doi.org/10.1007/978-94-017-9499-2_21.
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Posthuma, Leo, and Glenn W. Suter. "Ecological Risk Assessment of Diffuse and Local Soil Contamination Using Species Sensitivity Distributions." In Dealing with Contaminated Sites, 625–91. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-9757-6_14.
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Ghisi, Nédia de Castilhos, and Elton Celton de Oliveira. "Biomonitoring of Diffuse Contamination in the Subtropical Region of Brazil: Multibiomarker Assessment in Neotropical Freshwater Fishes." In Pollution of Water Bodies in Latin America, 255–73. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-27296-8_14.
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"Annexe 1 Propriétés physico-chimiques des polluants organiques et métalliques." In Contamination des sols, 127–32. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0260-9-010.
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"Sommaire." In Contamination des sols, iii—vi. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0260-9-toc.
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"4. Aliments d’origine animale et polluants organiques et métalliques." In Contamination des sols, 81–94. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0260-9-007.
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"Annexe 1 - Fiches bibliographiques relatives à des essais de plein champ." In Contamination des sols, 157–334. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0261-6-010.
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"4. Aliments d’origine végétale et éléments-traces." In Contamination des sols, 105–34. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0261-6-007.
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"Annexe 4 - Effets toxiques des éléments-traces en excès sur l’homme." In Contamination des sols, 389–402. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0261-6-013.
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"1. Rappels sur les éléments-traces." In Contamination des sols, 9–16. EDP Sciences, 2020. http://dx.doi.org/10.1051/978-2-7598-0261-6-004.
Conference papers on the topic "Contamination diffuse des sols":
1
Milej, Daniel, Ajay Rajaram, Androu Abdalmalak, Mahro Khalid, Marwan Shahid, Matthew Kewin, and Keith St. Lawrence. "Assessing extracerebral signal contamination in optical measurements of cerebral blood flow and oxygenation." In Diffuse Optical Spectroscopy and Imaging, edited by Hamid Dehghani and Heidrun Wabnitz. SPIE, 2019. http://dx.doi.org/10.1117/12.2527150.
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Su, Yi, Fengxiang Han, Safwan Shiyab, Jian Chen, and David L. Monts. "Accumulation of Mercury in Selected Plant Species Grown in Soils Contaminated With Different Mercury Compounds." In The 11th International Conference on Environmental Remediation and Radioactive Waste Management. ASMEDC, 2007. http://dx.doi.org/10.1115/icem2007-7123.
Abstract:
The objective of our research is to screen and search for suitable plant species for phytoremediation of mercury-contaminated soil. Currently our effort is specifically focused on mercury removal from the U.S. Department of Energy (DOE) sites, where mercury contamination is a major concern. In order to cost effectively implement mercury remediation efforts, it is necessary now to obtain an improved understanding of biological means of removing mercury and mercury compounds. Phytoremediation is a technology that uses various plants to degrade, extract, contain, or immobilize contaminants from soil and water. In particular, phytoextraction is the uptake of contaminants by plant roots and translocation within the plants to shoots or leaves. Contaminants are generally removed by harvesting the plants. We have investigated phytoextraction of mercury from contaminated soil by using some of the known metal-accumulating plants since no natural plant species with mercury hyperaccumulating properties has yet been identified. Different natural plant species have been studied for mercury uptake, accumulation, toxicity and overall mercury removal efficiency. Various mercury compounds, such as HgS, HgCl2, and Hg(NO3)2, were used as contaminant sources. Different types of soil were examined and chosen for phytoremediation experiments. We have applied microscopy and diffuse reflectance spectrometry as well as conventional analytical chemistry to monitor the phytoremediation processes of mercury uptake, translocation and accumulation, and the physiological impact of mercury contaminants on selected plant species. Our results indicate that certain plant species, such as beard grass (Polypogon monospeliensis), accumulated a very limited amount of mercury in the shoots (<65 mg/kg), even though root mercury accumulation is significant (maximum 2298 mg/kg). Consequently, this plant species may not be suitable for mercury phytoremediation. Other plant species, such as Indian mustard (Brassica juncea), a well-studied metal accumulator, exhibited severe chlorosis symptoms during some experiments. Among all the plant species studied, Chinese brake fern (Pteris vittata) accumulated significant amount of mercury in both roots and shoots and hence may be considered as a potential candidate for mercury phytoextraction. During one experiment, Chinese brake ferns accumulated 540 mg/kg and 1469 mg/kg in shoots after 18 days of growing in soils treated with 500 parts-per-million (ppm) and 1000 ppm HgCl2 powder, respectively; no visual stress symptoms were observed. We also studied mercury phytoremediation using aged soils that contained HgS, HgCl2, or Hg(NO3)2. We have found that up to hundreds of ppm mercury can be accumulated in the roots of Indian mustard plants grown with soil contaminated by mercury sulfide; HgS is assumed to be the most stable and also the predominant mercury form in floodplain soils. We have also started to investigate different mercury uptake mechanisms, such as root uptake of soil contaminant and foliar mercury accumulation from ambient air. We have observed mercury translocation from roots to shoot for Chinese fern and two Indian mustard varieties.
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Maria Cristina Trifu, Valeria Maria Daradici, Denis Mihailescu, and Ilie Calciu. "Geo-spatial analysis of the nitrate contamination of groundwater from diffuse sources." In 21st Century Watershed Technology: Improving Water Quality and Environment Conference Proceedings, May 27-June 1, 2012, Bari, Italy. St. Joseph, MI: American Society of Agricultural and Biological Engineers, 2012. http://dx.doi.org/10.13031/2013.41455.
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Mistry, Jignesh, Leena Shoemaker, Daniel Milej, and Keith St. Lawrence. "Assessing extracerebral contamination in cerebral blood flow pulsatility measured by diffuse correlation spectroscopy." In Optical Tomography and Spectroscopy of Tissue XV, edited by Sergio Fantini and Paola Taroni. SPIE, 2023. http://dx.doi.org/10.1117/12.2650380.
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Zheng, Jianan, Jie Chen, Tinghui Jiang, Yangpeng Zhang, and Zhizhong Zhao. "Effect of Copper Contamination on Atterberg Limits and Diffuse Double Layer of Expansive Clay." In 10th Academic Conference of Geology Resource Management and Sustainable Development 2022. Riverwood, NSW Australia: Aussino Academic Publishing House, 2022. http://dx.doi.org/10.52202/067798-0116.
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Cole, K. C., C. Lehto, and M. Yuhasz. "Detection Of Mould Release Agent Contamination On The Surface Of Epoxy-Based Composites By Diffuse Reflectance Fourier Transform Infrared Spectroscopy." In 1986 Quebec Symposium, edited by Paolo G. Cielo. SPIE, 1986. http://dx.doi.org/10.1117/12.938797.
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Piazza, Stefania, E. J. Mirjam Blokker, Mariacrocetta Sambito, and Gabriele Freni. "Comparison between the Top-down and Bottom-up approach for the diffuse-dispersive phenomenon analysis." In 2nd WDSA/CCWI Joint Conference. València: Editorial Universitat Politècnica de València, 2022. http://dx.doi.org/10.4995/wdsa-ccwi2022.2022.14067.
Abstract:
In order to detect deliberate or accidental contamination in drinking water distribution systems (DWDS), typically water quality sensors need to be installed in this system, and the data need to be analysed in order to feed alert systems and prevent the harm of contamination. This requires numerical (hydraulic and water quality) models that are as realistic as possible to support monitoring systems. Currently, water quality models used in the literature adopt an advective approach and simplified reaction kinetics, such as EPANET, which neglect diffusion-dispersion phenomena that are relevant in the presence of laminar and transient flow regimes. Another important aspect providing relevant uncertainty is related to the simplified estimation of sub-daily water demands that are commonly estimated from highly aggregated consumption data.The present study aims to analyse diffusion-dispersive phenomena in a realistic DWDS model, which shows turbulent, transitional and laminar flows, and compare this to how such a DWDS would typically be modelled with a coarse estimate of demands. We are therefore considering two different demand allocation approaches (Top-down and Bottom-up).In this paper the EPANET advective model and the diffusive-dispersive model, developed in a previous study, were used to better understand what the effect using the latter approach has within the DWDS as a function of two different types of demand allocation. To do this, the models results were compared to numerical tests that were performed on the real network of Zandvoort (the Netherlands) using a conservative tracer. For the 4 locations considered, it was noted that the diffusive-dispersive model responds well when using the bottom-up approach compared to the top-down approach. We found that in order to predict the tracer pattern, the Top-Down approach of demand allocation does not work well, even when an optimized diffusive-dispersive model is used. The bottom-up approach of demand allocation leads to far better results in predicting the tracer patterns, and with the diffusive-dispersive model the prediction improves even more. This means that in order to model water quality in a DWDS the first step should be to improve water demand models for this DWDS. This leads to an improved representation of flow regimes, and will most likely include laminar flows.
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Weiland, R., C. Boit, B. Ebersberger, P. Meis, N. Dawes, A. Dziesiaty, H. Zimmermann, et al. "Wafer Conserving Full Range Construction Analysis for IC Fabrication and Process Development Based on FIB/Dual Beam Inline Application." In ISTFA 2000. ASM International, 2000. http://dx.doi.org/10.31399/asm.cp.istfa2000p0393.
Abstract:
Abstract The step into the production line environment is a quantum leap for physical failure analysis (PFA) and will change its work in the near future. Wafer sacrifice for analysis becomes obsolete. The main benefits are: 1. reduction of wafer costs, 2. more splits per development lot, 3. reduced cycle time of analysis and technology development. Machines needed for that purpose are dual beam SEM/FIB tools. In the following we present solutions how PFA in a broad range can be carried out inside of a production line. The analyzed wafers can be fed back into the production flow which results in lower overall costs and the feedback loop to production engineers is dramatically shortened leading to reduced down times of production tools etc. The highest risk that has kept the majority of semiconductor manufacturers from proceeding into this direction is the contamination of the productive wafer with Ga, the FIB beam particle, that may diffuse into productive parts of the wafer during heat cycles after the analysis step. We show that the risk of contamination by Ga and other materials can be controlled.
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Deshayes, L., J. L. Evans, R. Ivester, D. G. Bhat, S. A. Batzer, and E. P. Whitenton. "Mechanical and Thermal Behavior for Machining Ti-6Al-4V With AlMgB14 and WC-Co Tools." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-81510.
Abstract:
Many tool materials dissolve, diffuse, and/or react with titanium due to the high temperatures at the tool/workpiece interface. Potential next generation tool materials that would improve the machining of titanium and eliminate the contamination of the work piece are being developed. One material, Aluminum Boride (AlMgB14), is the basis of the research presented in this paper. Specimens of the newly developed tool material, AlMgB14 were fabricated into a standard tool geometry. This tool material was compared with a standard WC-Co tool material to machine a Ti-6Al-4V workpiece. During orthogonal cutting, thermal and force measurements were made using both types of tool material. The measurements are compared with finite element simulations. This paper shows higher chip temperatures are obtained with AlMgB14 and this material demonstrates benefits associated with tool thermal conductivity, including improved chip segmentation, smaller cutting and thrust forces. Nevertheless, a weakness of AlMgB14 is its fracture toughness, which needs to be improved for better performance in an industrial environment.
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Moormann, Rainer. "A Safety Re-Evaluation of the AVR Pebble Bed Reactor Operation and Its Consequences for Future HTR Concepts." In Fourth International Topical Meeting on High Temperature Reactor Technology. ASMEDC, 2008. http://dx.doi.org/10.1115/htr2008-58336.
Abstract:
The AVR pebble bed reactor (46 MWth) was operated 1967–1988 at coolant outlet temperatures up to 990°C. Also because of a lack of other experience the AVR operation is a basis for future HTRs. This paper deals with insufficiently published unresolved safety problems of AVR and of pebble bed HTRs. The AVR primary circuit is heavily contaminated with dust bound and mobile metallic fission products (Sr-90, Cs-137) which create problems in current dismantling. The evaluation of fission product deposition experiments indicates that the end of life contamination reached several percent of a single core inventory. A re-evaluation of the AVR contamination is performed in order to quantify consequences for future HTRs: The AVR contamination was mainly caused by inadmissible high core temperatures, and not — as presumed in the past — by inadequate fuel quality only. The high AVR core temperatures were detected not earlier than one year before final AVR shut-down, because a pebble bed core cannot be equipped with instruments. The maximum core temperatures were more than 200 K higher than precalculated. Further, azimuthal temperature differences at the active core margin were observed, as unpredictable hot gas currents with temperatures > 1100°C. Despite of remarkable effort these problems are not yet understood. Having the black box character of the AVR core in mind it remains uncertain whether convincing explanations can be found without major experimental R&D. After detection of the inadmissible core temperatures, the AVR hot gas temperatures were strongly reduced for safety reasons. Metallic fission products diffuse in fuel kernel, coatings and graphite and their break through takes place in long term normal operation, if fission product specific temperature limits are exceeded. This is an unresolved weak point of HTRs in contrast to other reactors and is particularly problematic in pebble bed systems with their large dust content. Another disadvantage, responsible for the pronounced AVR contamination, lies in the fact that activity released from fuel elements is distributed in HTRs all over the coolant circuit surfaces and on graphitic dust and accumulates there. Consequences of AVR experience on future reactors are discussed. As long as pebble bed intrinsic reasons for the high AVR temperatures cannot be excluded they have to be conservatively considered in operation and design basis accidents. For an HTR of 400 MWth, 900°C hot gas temperature, modern fuel and 32 fpy the contaminations are expected to approach at least the same order as in AVR end of life. This creates major problems in design basis accidents, for maintenance and dismantling. Application of German dose criteria on advanced pebble bed reactors leads to the conclusion that a pebble bed HTR needs a gas tight containment even if inadmissible high temperatures as observed in AVR are not considered. However, a gas tight containment does not diminish the consequences of the primary circuit contamination on maintenance and dismantling. Thus complementary measures are discussed. A reduction of demands on future reactors (hot gas temperatures, fuel burn-up) is one option; another one is an elaborate R&D program for solution of unresolved problems related to operation and design basis accidents. These problems are listed in the paper.