Dissertations / Theses on the topic 'Metals/metalloids'

Although hydromechanical lake remediation projects have been carried out over several decades, there still is a lack of evidence about the changes in environmental status after such projects, while scientific literature regarding redistribution of metals and metalloids caused by hydromechanical bottom sediment removal is especially scarce both in Lithuania and in other countries. Research of the dissertation consisted not only of extensive geochemical field work and laboratory analysis, but also methods of mathematical statistics and spatial interpolation. Results of the research and their analysis allowed to conclude that hydromechanical lake remediation results in changes of the contents of metals and metalloids of interest and their spatial redistribution in lake bottom sediments, which are specific to each metal and metalloid, thus cumulative indicators should be used to assess overall changes in sediment quality of remediated lakes. Calculation and statistical analysis of on of such indicators - total sediment contamination index (Zd) and surface interpolation of its values allowed to evaluate statistical significance of changes in contamination degree of the newly formed surface sediment layer and to assess cumulative spatial redistribution of metals and metalloids caused by hydromechanical lake remediation. Data provided in the dissertation is especially significant in preparation and design of future sediment removal projects and in determining their feasibility.
Nors hidromechaninio ežerų valymo darbai vykdomi jau daugelį metų, iki šiol nėra aišku, kaip pasikeičia ežero aplinkosauginė būklė po jo išvalymo, o Lietuvos ir kitų šalių mokslinėje literatūroje informacijos apie valymo sąlygotus metalų ir metaloidų pasiskirstymo dugno nuosėdose pokyčius yra stebėtinai mažai. Disertacijos tyrime buvo taikoma kompleksinė šių pokyčių vertinimo sistema, pasitelkiant ne tik išsamius geocheminius lauko ir laboratorinius tyrimus, bet ir matematinę statistinę analizę bei erdvinę duomenų prognozę ir interpoliaciją. Tyrimų ir analizės rezultatai parodė, kad hidromechaninis ežero valymas sąlygoja nagrinėjamų metalų ir metaloidų kiekių pokyčius ir jų persiskirstymą dugno nuosėdose, kuris yra savitas atskiriems cheminiams elementams, todėl siekiant nustatyti valymo darbų įtaką būtina naudoti indikatorius, leidžiančius įvertinti bendro, kumuliacinio nuosėdų užterštumo lygio pokyčius visų nagrinėjamų elementų atžvilgiu. Vieno iš tokių indikatorių – suminio užterštumo rodiklio Zd verčių statistinė analizė ir erdvinė interpoliacija leido ne tik nustatyti statistiškai patikimą hidromechaninio ežero valymo įtakotą metalų ir metaloidų pokyčių reikšmingumą naujai susiformavusiame paviršiniame dugno nuosėdų sluoksnyje, bet ir pademonstruoti erdvinį šių elementų perskirstymą dugno paviršiaus plote. Disertacijoje pateikiama informacija yra ypač aktuali vertinant Lietuvos ežerų būklę, planuojant ežerų dugno nuosėdų šalinimo darbus ir nustatant jų tikslingumą.

Mining activities generate aerosol in a wide range of sizes. Smelting activities produce mainly fine particles (<1 μm). On the other hand, milling, crushing and refining processes, as well tailings management, are significant sources of coarse particles (>1 μm). The adverse effects of aerosols on human health depend mainly on two key characteristics: size and chemical composition. One of the main objectives of this research is to analyze the size distribution of contaminants in aerosol produced by mining operations. For this purpose, a Micro-Orifice Uniform Deposit Impactor (MOUDI) was utilized. Results from the MOUDI samples show higher concentrations of the toxic elements like lead and arsenic in the fine fraction (<1 μm). Fine particles are more likely to be deposited in the deeper zones of the respiratory system; therefore, they are more dangerous than coarse particles that can be filtered out in the upper respiratory system. Unfortunately, knowing the total concentration of contaminants does not give us enough information to identify the source of contamination. For this reason, lead isotopes have been introduced as fingerprints for source apportionment. Each source of lead has specific isotopic ratios; by knowing these ratios sources can be identified. During this research, lead isotopic ratios were analyzed at different sites and for different aerosol sizes. From these analyses it can be concluded that lead isotopes are a powerful tool to identify sources of lead. Mitigation strategies could be developed if the source of contamination is well defined. Environmental conditions as wind speed, wind direction, relative humidity and precipitation have an important role in the concentration of atmospheric dust. Dry environments with low relative humidity are ideal for the transport of aerosols. Results obtained from this research show the relationship between dust concentrations and meteorological parameters. Dust concentrations are highly correlated with relative humidity and wind speed. With all the data collected on site and the analysis of the meteorological parameters, models can be develop to predict the transport of particles as well as the concentration of contaminants at a specific point. These models were developed and are part of the results shown in this dissertation.

This work reports the use of the vibrating gold microwire electrode, with new methods developed for the speciation of Zn, Cu, Mn and As at natural levels in waters of neutral pH. Trace metals and metalloids can be distributed as different species in the environment, which can control mobility, toxicity and bioavailability and in turn depends on many complex factors. Analysis of this distribution (speciation) can provide an understanding of the relationship between such elements and their relationship with organisms in marine environments and humans through contaminated drinking water supplies. Such speciation can be analysed using a vibrating gold microwire electrode (VGME), which is easily prepared and maintained at minimal cost. High sensitivity is found for trace metals: Mn; Cu and Zn; and the metalloid As, resulting from a very low diffusion layer (~0.8 urn for a Sum gold wire) means that they can be measured at trace levels in natural waters. This combined with the VGME's portability, reliability and stability for long term measurement (repeated measurements over several days) and its capability to distinguish between distinct forms ofthe above trace elements mean that speciation methods could be successfully developed and validated in natural waters, with no, or minimal sample preparation. Such methods made it possible to analyse speciation on-site, which decreases the potential problems inherent in maintaining sample speciation during storage. Contamination of groundwater with As is a major health risk through contamination of drinking and irrigation water supplies. In geochemically reducing conditions As is mostly present as ASIII, which is why a method that uses cathodic stripping voltammetry (CSV) to determine reactive AS"I was developed. The ASIII is detected after adsorptive deposition of As(OHho, followed by a potential scan to measure the reduction current from AsIII to Aso. The method is suitable for waters of pH 7-12. The CSV method was successfully applied to groundwaters from Severn Trent, UK, however speciation using this method is severely hampered by high levels of iron and manganese. Experiments showed that the interference is eliminated by addition of EDTA, making it possible to determine the arsenic speciation on-site by CSV in West Bengal, India. The VGME is also used to detect nanomolar levels of dissolved Mn by anodic stripping chronopotentiometry (ASC) and sub-nanomolar levels of dissolved Zn by anodic stripping voltammetry (ASV) in neutral pH seawater. The limits of detection for Mn (1.4 nM) and for Zn (0.3 nM) in seawater with a 300 s plating time, are better than achieved using other non-mercury based electrodes and nearly as good as a mercury film electrode for Zn. Deposition of Mn at the VGME was further utilised to catalyse the reduction of Asv to ASIII, enabling for the first time the direct electrochemical determination of Asv in natural waters of neutral pH including seawater by ASV using a manganese coated gold microwire electrode. Direct electrochemical determination of Asv in neutral pH waters is impossible due to its electro-inactivity. Therefore Mn is added to excess (~1 JlM Mn) to the water leading to a Mn coating during the deposition of Asv on the electrode, when depositing at -1.3 V. The detection limit was 0.2 nM Asv using a deposition time of 180 s. Speciation of Cu is determined without the need for sample preparation, using scanned stripping techniques for the first time at natural levels in seawater. A desorption potential (-1.2 V) and a conditioning interval between scans make the VG ME suitable for on-site and potentially in-situ copper speciation. The resulting pseudopolarograms are analysed using an experimentally constructed 'chelate scale' to determine the strength of copper ligand interactions in real seawater samples.

Some metals and metalloids make significant contributions to the harmful effects of tobacco consumption although understanding the mechanisms involved in toxicity is hampered by the lack of information on their chemical and valence species, both in tobacco and in smoke. This research addresses the speciation of the metals and metalloids most frequently implicated, particularly those elements that exist in nature in multiple valence states, namely arsenic (As) and chromium (Cr), there being considerable differences in toxicity with oxidation state. A strategy was devised to overcome some of the problems that have thwarted earlier attempts at speciation. Firstly tobacco plants were cultivated under controlled conditions in compost burdened with high levels of metals and metalloids resulting in leaf with up to 250 µg g⁻¹ As, although Cr uptake was less successful. Secondly valence speciation even at the exceptionally low concentrations of As and Cr in smoke from unburdened tobacco was achieved with XANES analysis using the exceptionally bright Diamond synchrotron source. This revealed that combustion of tobacco has a marked effect on valence speciation with As(III), the reduced form of As, dominating (and persisting) in condensate of tobacco smoke while ash is dominated by the oxidised form, As(V). Chromium also appears to be present in smoke mainly as reduced Cr(III) species. HPLC-ICPMS analysis of arsenic indicates the dominance of inorganic over organic species (~4:1). Other metals were investigated in less detail. These findings establish that arsenic is present in smoke in its most toxic form and represents a significant risk to health. Conversely smokers appear to be exposed to the less harmful species of chromium. These results support a recent WHO report that includes As but not Cr in a list of four metals and metalloids recommended for regulation in crops and commercial products in the interests of public health.

La gestion et la conservation des lacs de haute montagne Pyrénéens dans le contexte actuel du changement climatique et de l’augmentation de la pression anthropique nécessitent une connaissance approfondie de leur fonctionnement biogéochimique. Dans cette thèse, cinq campagnes d’échantillonnage ont été réalisées (2017-2019) dans plus de 20 lacs alpins. L’analyse d’échantillons d’eau nous a permis d’étudier les teneurs, les profils en profondeurs, la répartition géographique, et les variations saisonnières de nombreuses caractéristiques physico-chimiques et biogéochimiques. Le cycle du dioxyde de carbone (CO2) et le devenir des Eléments Traces Potentiellement Dangereux (PHTEs) ont été étudiés. Le mercure (Hg) a été particulièrement étudié au travers du développement d’une procédure analytique pour la détermination de concentrations en traces dans les eaux naturelles et de recherches biogéochimiques sur la distribution et le devenir des espèces du Hg dans la colonne d’eau, et dans des archives de sédiments.La procédure développée pour analyser l’alcalinité totale (TA) et le carbone inorganique dissous (DIC) nous a permis de déterminer les autres paramètres du système du CO2, le pH et la fugacité du CO2 (fCO2). Les spécificités du substrat rocheux apparaissent essentielles pour l’état d’acidification des lacs étudiés. De plus, les valeurs de fCO2 obtenues montrent que les lacs sont des sources de CO2 pour l’atmosphère.La mesure de divers paramètres physico-chimiques nous a permis de classer les lacs en fonction de leur géochimie de l’eau mettant en évidence l’importance de l’état trophique des lacs, des caractéristiques géologiques et des apports atmosphériques. La présence, les sources et le comportement des PHTEs ont été étudiés, démontrant un contraste entre les apports géologiques et atmosphériques. Le suivi intensif a démontré que certains PHTEs sont très sensibles aux changements environnementaux comme la température et les conditions redox.La mesure des concentrations de Hg total dans les systèmes aquatiques reste complexe et il est nécessaire de développer des méthodes analytiques moins coûteuses et faciles d’utilisation. La méthode développée et optimisée dans ce travail a été appliquée avec succès et a montré une bonne limite de détection et une excellente répétabilité. La spéciation du Hg dans la colonne d’eau a démontré l’état intact et la dynamique des lacs Pyrénéens. L’homogénéité dans les concentrations de Hg total non-gazeux a confirmé l’absence de sources locales et l’utilisation potentielle de ces écosystèmes en tant que sentinelles de la contamination régionale et globale du Hg. Alors que lemercure inorganique (iHg) n’a pas montré de variations saisonnières, le monométhylmercure (MMHg) a été significativement plus élevé en automne 2018 et le mercure gazeux dissous (DGM) a fortement varié parmi les lacs. Les expérimentation in-situ ont confirmé les conditions qui favorisent la méthylation (eaux anoxiques stratifiées), la déméthylation et la photoréduction (intense lumière UV) du Hg.L’analyse des archives de sédiments a mis en lumière les tendances temporelles des taux d’accumulation du Hg (HgARs), avec une augmentation progressive depuis le 16ème siècle et l’industrialisation, reflétant la production de Hg dans les mines d’Almadén. Les isotopes stables du Hg permettent de tracer certaines sources anthropiques ainsi que les variations climatiques passées.Globalement, les changements environnementaux dans les écosystèmes des lacs, provoqués à la fois par les conditions climatiques (température, intensité lumineuse) et la pression anthropique (apports atmosphériques, eutrophisation, CO2 atmosphérique) sont susceptibles d’entrainer des répercussions importantes parmi le CO2, certains PHTEs et le cycle biogéochimique du Hg dans les écosystèmes montagnards
The management and conservation of Pyrenean high mountain lakes within the current context of climate change and increasing anthropogenic pressure require detailed knowledge of their biogeochemical functioning. In this doctoral thesis, five sampling campaigns were carried out (2017-2019) in more than 20 alpine lakes. The analysis of water samples allowed us to study the occurrence, the depth profiles, the geographical distribution and the seasonal trends of a large array of physico-chemical and biogeochemical parameters. Specifically, the cycle of carbon dioxide (CO2) and the fate of Potentially Harmful Trace Elements (PHTEs) were investigated. The mercury (Hg) was specially studied through the development of an analytical procedure for the measurement of trace concentrations in natural waters and through biogeochemical investigations on the distribution and the fate of Hg species in the water column, as well as in sediment archives.The new and robust procedure developed in this work to measure the total alkalinity (TA) and the dissolved inorganic carbon (DIC) allowed us to determine the other two parameters of the CO2 system, the pH and the fugacity of CO2 (fCO2). The bedrock characteristics of the watershed appear to be the most important parameters influencing the acid status of the studied lakes. Moreover, obtained fCO2 values indicate that lakes are sources of CO2 for the atmosphere.The measurement of various physico-chemical parameters allowed us to discriminate and classify the studied lakes according to their water geochemistry, highlighting the importance of the trophic status of the lakes, the geological background and the atmospheric inputs. The occurrence, sources and behaviour of the PHTEs were investigated with evidence of a contrast between geological and atmospheric inputs. Intensive monitoring revealed some PHTEs to be highly sensitive to environmental changes such as temperature and redox conditions.Monitoring natural concentrations of total Hg in aquatic systems remains a difficult challenge and there is a need for the development of low cost and easy handling analytical methods. The method for analysis of trace Hg concentrations developed and optimized in this work was successfully operational and exhibits a suitable limit of detection and an excellent reproducibility. Hg speciation results in the water column demonstrated the pristine state and the dynamic of the Pyrenean lakes. The homogeneity in the non-gaseous total Hg concentrations in the studied lakes confirmed the absence of local sources and the potential use of these ecosystems as sentinels of regional to global Hg contamination. While inorganic mercury (iHg) did not show seasonal variations, monomethylmercury(MMHg) was significantly higher in autumn 2018 and dissolved gaseous mercury (DGM) varied strongly within and among lakes. In-situ experiments confirmed the conditions that promote Hg methylation (stratified anoxic waters), demethylation and photoreduction (intense UV light).The historical Hg record in sediment archives highlighted temporal trends in Hg accumulation rates (HgARs) with a progressive increase since the 16th Century and the industrialization, mirroring the Hg production in Almadén mines (Southern Spain). Besides, Hg stable isotopes allow the identification of distinct anthropogenic sources as well as past climate variability.Overall, environmental changes in lake ecosystems, induced by either climatic conditions (temperature, light intensity) or anthropogenic pressure (atmospheric inputs, eutrophication, atmospheric CO2) are likely to produce significant impacts among CO2, specific PHTEs and Hg biogeochemical cycles in mountainous ecosystems

Mestrado em Engenharia do Ambiente - Instituto Superior de Agronomia
Wastes of a former steel industry were deposited during 40 years on the left bank of the Coina River, an affluent of the Tagus River, near its estuary, creating a landfill that is connected to the river itself. Tides penetrate and exit the landfill, creating a periodic lagoon that shows resemblances to the salt marshes nearby, being colonized by salt marsh plants. This study aims: a) to evaluate the level of contamination of the lagoon by doing a biogeochemi-cal study, b) to evaluate the level of dispersion of the contaminants through a leaching assay, and c) to evaluate the capacity of Tamarix africana Poiret to be used in the phytostabilization of the contaminated sediment. The sediment is considered contaminated by As, Cd, Cr, Cu, Pb and Zn. It also presents high con-centrations in Fe and Al. The contaminant chemical elements seem to be associated to the sediment phases (adsorbed, co-precipitated etc.), as the concentrations of the elements were very low in pore water and leachates, as well as in the river water. Salt marsh plants are able to uptake contaminants without showing signs of toxicity, being the contaminants mostly retained in the roots. Tamarix africana shows potential to be used for phytostabilization, but with caution, as this species can excrete contaminants by its leaves leading to the precipitation of salts.

Oruro est situé dans l'Altiplano Bolivien à 230 km au sud de La Paz. Le principal système hydrologique est endoréique et est constitué par les sous-bassins du lac Titicaca-rivière Desaguadero-lac Poopó-salar du Coipasa (TDPS). Cette zone présente une saison sèche (DS) et une saison humide (WS). Malgré l'existence de la WS, les précipitations sont rares, néanmoins, l'intensité augmente interannuellement associé aux événements ENSO. Géomorphologiquement, ce site est composé de: l'Altiplano et la Cordillère Occidentale liés aux dépôts épithermaux et Cu et la Cordillère Orientale liée aux nombreuses ceintures métallogéniques, la plus connue est la ceinture de Sn. Le Département d'Oruro est situé dans la partie centrale de cette ceinture, et malgré le fait que cette ville a été soumise à des activités minières depuis le XVIIème siècle, les caractéristiques géochimiques et les processus de dispersion qui affectent cette zone sont peu connus. Les faits exposés précédemment, ont motivé une étude géochimique détaillée des carottes sédimentaires lacustres dans ce domaine. Deux campagnes de carottage (DS et WS) ont permit de récupérer 5 carottes sédimentaires, 4 dans le lac Uru Uru (2 en DS et 2 en WS) et une à la lagoon Cala Cala (18 km E d'Oruro), ce dernier pour déterminer le fond géochimique local. Analyses de laboratoire ont été effectuées au Laboratoire des Mécanismes et Transferts en Géologie (LMTG, Toulouse), où un total de 91 échantillons de sédiments et 222 échantillons des eaux interstitielles (PW) ont été étudiés. Le fond géochimique et les sources des éléments traces nous ont permis de proposer que le fond géochimique naturel de As et Sb est significativement plus élevé par rapport de la croûte continentale supérieure (UCC), les niveaux de fond mondial, les centres industriels et les sites miniers historiques. Ces conclusions nous ont permis de soutenir l'utilisation des coefficients d'enrichissement (EF) locaux et jeter l'utilisation de l'UCC pour calculer les EFs. Il existe une multiplicité de sources des contaminants qui ont difficulté la discrimination entre apports naturelles et apports anthropiques dans ce bassin. Cependant, nous proposons que l'impact anthropique dans les sols superficiels est liée à la dispersion des éléments traces par la Fonderie de Vinto, tandis que le lac Uru Uru est plutôt influencé par les activités minières. Études de diagenèse précoce, nous ont permis de déterminer que les éléments traces au sein du lagoon Cala Cala sont moins disponibles et mobiles que dans le lac Uru Uru et des fortes concentrations des éléments traces en solution sont expliqués par la proximité des ceintures métallogéniques situées le long de la Cordillère Orientale, et non par influence anthropique. Le nord du lac Uru Uru présente des concentrations inférieures moyennes des éléments traces dissous et leur comportement est fortement associée à des changements saisonniers, parce que l'environnement réductrice atteint au cours de la WS entraîne la libération des éléments traces que la dissolution réductrice des oxyhydroxides de Mn a lieu. Dans ce domaine, le comportement des éléments traces dans l'état solide montrent des changements modérés entre les différentes saisons. Les éléments traces dans le sud du lac Uru Uru sont les plus réactifs, disponibles et mobiles. Au cours de la DS le comportement des éléments traces dissous est associé à l'évaporation, cette réaction n'a pas été observée au cours de la WS. Les plus fortes concentrations du Sb et Mo dissous se trouvent dans cette région pendant les deux saisons et Cd que pendant la DS. Dans ce domaine, le partitionnement à l'état solide (SSP) montre des changements de fractionnement importants lors de la WS, impliquant que les éléments traces peuvent être facilement libérés dans l'eau interstitielle lorsque les conditions de réduction sont établies, les éléments les plus instables sont Mo, U, Sb, Pb et Cd. Cette zone affiche le souci environnemental plus important, parce que, encore l'influence de la WS, on trouve l'influence anthropique associé à la Mine de Huanuni, probablement en apportant Sb (et Mo) dissous (et comme le montre autre étude, Mo représente une compétition pour le Cu en induisant des carences alimentaires pour animaux de ferme). Nous soulignons que c'est dans ce domaine où la plupart de la flore et faune vive et de la pêche est généralement pratiqué. On recommande de déterminer le comportement des éléments traces dans la WC, spécialement au cours de la WS et La Niña événements. En ce qui concerne l'influent de l'exploitation minière et le climat sur le dépôt des sédiments dans l'Altiplano, il a été déterminé que au cours du dernier siècle, l'exploitation et la production de Sn a influencé le dépôt de Sb-Ag-Pb dans les sédiments du lac Uru Uru. En outre, événements ENSO pourraient jouer un rôle important dans la production de minéraux authigènes pendant la diagenèse précoce. Enfin, nous proposons que le dépôt des éléments traces est influencé principalement par trois sources: la géologie locale, la formation des minéraux authigènes sous l'influence probable des événements froids ENSO (La Niña) et les gangues et minerais d'origine minérogénétiques.

Mining operations, including crushing, grinding, smelting, refining, and tailings management, are a significant source of airborne metal and metalloid contaminants such as As, Pb, Cd and other potentially toxic elements. Dust particles emitted from mining operations can accumulate in surrounding soils, natural waters and vegetation at relatively high concentrations through wind and water transport. Human exposure to the dust can occur through inhalation and, especially in the case of children, incidental dust ingestion, particularly during the early years when children are likely to exhibit pica. Furthermore, smelting operations release metals and metalloids in the form of fumes and ultra-fine particulate matter, which disperses more readily than coarser soil dusts. Of specific concern, these fine particulates can be transported to the lungs, allowing contaminants to be transferred into the blood stream. The main aim of this research is to assess the role of atmospheric aerosol and dust in the transport of metal and metalloid contaminants from mining operations to assess the deleterious impacts of these emissions to ecology and human health. In a field campaign, ambient particulates from five mining sites and four reference sites were examined utilizing micro-orifice deposit impactors (MOUDI), total suspended particulate (TSP) collectors, a scanning mobility particle sizer (SMPS), and Dusttrak optical particle counters for an understanding of the fate and transport of atmospheric aerosols. One of the major findings from size-resolved chemical characterization at three mining sites showed that the majority of the contaminant concentrations were found in the fine size fraction (<1 micrometer). Further, metal and metalloids (e.g. As, Cd, and Pb) around smelting activities are significantly enriched in both the coarse and fine size fraction when compared to reference sites. Additionally, with dust events being a growing concern because of predicted climate change and mine tailings being a significant source for dust, high wind conditions around mine tailings were studied for dust generation. Relative humidity was found to play an important predicting role in atmospheric dust concentration. More generally, findings indicate mining activities remain a serious threat to human health and ecology despite the regulations in place to protect from their pollution.

Introduction The work carried on in the triennium 2007-09 put itself in the field of research known as phytoremediation. This term identifies several techniques (phytoextraction, phytostabilization, phytovolatilization) based on using different plant species able to survive on substrates contaminated by many pollutants derived from human activities and to accumulate them in own tissues or volatilize by evapotranspiration or avoiding their leakage troughout the groundwater . This ability varies strongly trough species and inside a species between genetic pools. About the ability in heavy metals removing , researchers have identified two classes of plant species : Hyperaccumulators : species tipical of metalliferous soils, able to carry on their life cycle without showing symptoms of stress as heavy metals high concentration. (Baker et al., 2000). To be classified as hyperaccumulator a plant species must accumulate a minimum of : 100 mg/Kg d.w. of Cd, 1000 mg/Kg d.w. of Pb, 10000 mg/Kg d.w. of Zn ; ranges for As are not yet determined. (Baker and Brooks 1989, Baker et al., 2000). Some of most rapresentative hyperaccumulator species are Thlaspi caerulescens, Arabidopsis halleri and Viola calamarina, Astragalus spp and several other species of following families : Cariophyllaceae, Fabaceae, Poaceae, Chenopodiaceae, Brassicaceae e Cyperaceae. About As the best accumulator is Pteris vittata. The main limit of hyperaccumulators is little biomass production. Accumulators: in this group there are herbaceous and woody species able to couple a good accumulation with a good biomass production. Between them we can find Brassica juncea, end the genus Salix. This kind of accumulators are the best solution for pollutants removal programs in short and medium period. An high biomass production allows to plan a recycle of it in energy production and to recover heavy metals from ashes. ((Kabata-Pendias and Pendias, 1992 ; Pullford and Dickinson 2004 ; Paulson et al 2003; French et al 2005; Ebbs et al 1997 ; Ebbs et al 1998). This work, divided in several steps, as described below, wants to increase the knowledge on some of previous species, from a physiological point of view and evaluating performances of accumulation in order to replace, when it’s feasible, invading and expensive remediation techniques with phytoremediation that is, in its different applications, more respectful of landscape and more cost-effective. Trials to evaluate phytoextraction performances of four species of willow (Salix spp) , Phragmites australis and Brassica juncea grown on polluted sludge dredged from Venice Lagoon. In collaboration with Department I.M.A.G.E. of Faculty of Engenering of University of Padova, in the field of PRIN 2005 (National Significant Project) “Remediation of sea, lagoon and river sediments” experimental trials were planned in order to understand remediation and biomass production potential of Salix matsudana, S. babylonica, S. alba, S. fragilis, Brassica juncea and Phragmites australis growing on salty polluted sludge , dredged from Venice Lagoon (closest to Marghera harbor) and to think about a phytoextraction installation. Sludge samples were kept in four sites (North industrial channel, West industrial channel-two samples-, and Evolution Basin), then labeled and characterized. To dry, homogenize and ameliorate their drainage capability of sludge, samples were mixed with river sand in a 1:1 ratio. Trial on 50 L tanks : After preliminary trials that underlined impossibility to grow up in field conditions Salix babylonica, fragilis , alba, , Thypha latifolia and Zea mais, seven 50 L tanks were filled up with a bottom layer of expanded clay and sludge up to 35 L (2 with Phragmites, 2 with Salix Matsudana, 2 with Brassica juncea and one without plants ) each one with a tube coupled with a filter, linked in the bottom to collect water samples and favorite drainage. Willow cuttings and Indian mustard seedlings were planted with a universal soil bulk to attenuate transplanting shock and negative effect on young root system of direct contact with polluted substrate, Phragmites rhizomes instead, after an initial steady state, showed to be able to grow on direct contact with sludge. After two months from start of trial, EDTA was added to one of Phragmites tanks to increase phytoextraction performances. Hydroponic trials : hydroponic livestocks of S. Matsudana, S. Alba, S. Fragilis, s. Babylonica and Brassica juncea were prepared mixing Hoagland nutrient solution with same Ni, Cd, Zn, Cu and Pb concentrations detected in first water sample collected from tanks. For each willow species, were prepared one becker as control with Hoagland solution only, one with Hoagland plus metals and one with Hoagland, metals plus NaCl, supplied at increasing concentrations (from 0.05 M to 0.2 M). About brassica, five beckers with 40 seedlings for each one were prepared. One becker as control with Hoagland solution, two beckers with Hoagland plus metals in the same concentration as described above, and two beckers with metals plus raising up Na concentration as described above. At the end of experimental period, cuttings and seedlings were harvested, weighted and metals and Na contents were detected. Twenty L tanks trials : five 20 L tanks with a tap on the bottom were filled up with a layer of fine gravel, a layer of sludge and a top layer of universal soil. They were placed in growth chamber. Each tank hosted three cuttings (one species for each tank) and eight Paspalum vaginatum plants, the fifth one hosted a second series of S. Babylonica cuttings and eight Paspalum vaginatum plants. Trials were 50 days long. A week after trial start, in fifth tank EDDS chelant was added, in order to increase metals bioavailability. After plant harvesting, biometric and metal content measurement were done. Willow root deepening evaluation: to see possible differences in sediment exploration by root systems of willow species twenty four 2 L plastic bottles were prepared. Sixteen of that filled up with same 20 L tank content, and eight (two for species) with grave’, universal soil on the top and soil kept from Experimental farm “L.Toniolo”. Each bottle hosted a cutting (six bottles for species). At the end of trial, willow shoots were removed, then bottles were frozen and sawed in three sections corresponding to universal soil layer and two part of sludge layer corrispondenti alla sezione contenente il terriccio e a due parti conteneti il sedimento. All root systems were extracted, washed up, weighted, scanned and analyzed to determine total length and diameter. Results : Phragmites : we can see an EDTA effective action on Cd, Ni, Pb Zn and Na accumulation in shoots while in rhizomes, there are significative differences only about Pb and Na. No differences in term of biomass production. EDTA became more available Cu and Zn in soil solution; nevertheless metals concentrations remain pretty low. Willows in growth chamber : no differences in leaves accumulation between species while Babylonica EDDS treated became the best performer in Cu, Ni, Pb and Zn accumulation, while it diminuish Na concentration. In stems babylonica appears the best, with and without EDDS for Cu, Zn and Na. About roots Babylonica is again one of best performer in Na, Zn and Cd accumulation. No differences between species or treatment in Ni accumulation. Comparing growth chamber willows with S. matsudana grown in field conditions, this one shows best performaces in leaves accumulation for Na (followed by “growth chamber matsudana”, fact that confirms the ability of the species in Na translocation), and for Cd and Ni with babylonica EDDS treated. In stems, “field matsudana” is the best accumulator of Na, Pb and Ni and it remains the best performer for root system except for Na. hydroponic trials confirm in leaves the strong competition of Na versus accumulation of other anions, particularly versus Cd, Ni, Pb and Zn ; competition versus Cu appears lighter instead. In stems le migliori performances di S. babylonica is the best accumulator of Cd, Cu, Zn and Ni, nevertheless it appears at the same time the best Na accumulator. In root system too babylonica is the best accumulator of Cd, Ni Zn and Na. The roots deepening evaluation trial shows in comparison with control of each species that babylonica root system should be the less suffering (according to accumulation data), while between four species grown on sludge Salix alba shows the deepest root system coupled with smallest diameters. This two characteristics should be a signal of less stress as found by Vamerali et al. 2008. Brassica juncea hydroponic trial show clearly interference of Na in metals accumulation. Anyway accumulation performances in hydroponic are clearly better than that ones of brassica grown in field conditions, also in presence of Na. It should mean that : Ahydroponic trial in this case isn’t reliable in a comparison with field conditions B) probably other limiting factors, as nutrients could affect metal accumulation and biomass production that is pretty low also because the quick flowering, another symptom of stress. Interaction of selenate and molybdate with the transport and assimilation of sulfate in Brassica juncea Recently MOT1, a transporter with an high affinity for Mo was identified in Arabidopsis thaliana (Tomatsu et al., 2007), but it’s common opinion plants could uptake Mo also using S transporters because the two anions are analogs and could compete in binding of active site of the same transporters (Dudev e Lim 2004; Alhendawi et al 2005). Once inside the cell, Mo can interfere with S methabolism becoming substrate for reactions catalyzed by ATP sulfurilase (APS), as is selenate, but in contrast to selenate no Mo containing products are formed in the reaction (Reuveny 1977). Given the significant impact that S fertilizers application may have on Mo and Se distribution and accumulation in plants (Shinmachi et al., 2010), this work studied interactions of sulfur nutrition with molybdenum and selenium in Brassica juncea. To this aim Brassica juncea seedlings were grown with different combinations of S and Se or S and Mo. Experiments were carried out in a short time (24h) as selenate and molybdate were given to plants at a very high concentration (200 µM), which was the same of sulfate in the S-sufficient condition. Chemical and physiological analyses were performed, including quantification of elements and plant growth. Tolerance index (% of fresh weight relative to the control) and root/shoot ratio show a greater stress for plants grown in S deficiency and in presence of Se and Mo. Se and Mo were more absorbed in minus S condition. Both for total S and sulfate Se and Mo competition becomes clear only between 6 and 24 h of treatment, while within an hour there are not significant changes in S uptake. Study on potential effects of Se accumulation on drought stress in Brassica juncea e Stanleya pinnata . Some Se accumulator species (Brassica spp, Stanleya spp, Astragalus spp.) uses Se accumulated as a weapon against herbivors (Freeman et al., 2007; Galeas et al. 2007 ; ) Brassica juncea , differently from other toxic or potentially toxic trace elements, accumulates Se also in flowers and seeds giving value to the hypothesis of an happening evolutionary in the use of Se against parassites and herbivors adaptation (Quinn C. et al., 2008). This two species were grown up in gravel and in hydroponic in presence (20 µM) and in absence of Sodium selenate. The water deficit was experimented at first on gravel by irrigation stopping for 8 days, then in hydroponic by adding polietilenglicol (PEG 10000), to modify Ψw of nutrient solution. In two hydroponic trials’ Ψw was brought to -1.3 / -1.6 Mpa. Measures of photosintetic efficency, biomass and water and osmotic potential show that there are no evidences of a positve effect of Se on drought tolerance except for the non stress condition or light stress (-0.5/-0.6 Mpa). This action, actually not very strong, increase biomass production in plants treated with selenate according to trials on Triticum aestivum (Yao Xiaoqin et al. ; 2009). Study of potentials of Se-accumulator Astragalus racemosus and non accumulator Astragalus convallarius as Ni, Mo, Cr, V, W, Te, Se and As accumulators. The genus Astragalus is composed by many species distributed in northern america, some of that adapted to live in seleniferous soils, so able to develop an high tolerance versus Selenium (Cowgill, 1990). Concentration of Arsenic, Nichel Chromium, Vanadium, Tellurium, Tungsten and Molibdenum raised up in the environment because human activities ( Bamhart 1997 ; Zarchinas et al 2004 ; Zoller et al. 1973 ; Gott and McCarthy 1966 ; ) . the aim of this work is to understand if adaptation to Se accumulation is effective also versus other elements, some of them analogs of Se. These two species of Astragalus germinated in Petri dishes then grown up in growth chamber for 3 months in Murashige & Skooge addicted agargel plus salts of elements mentioned above , mixed in different concentrations based on their degree of toxicity, in order to avoid a too quick death. Results showed that Se hyperaccumulator is not always more tolerant than the non accumulator (A. Convallarius showed more tolerance in V accumulation). Effects of Cu deficiency on Cu-proteins activity and on expression of laccases in leaves and stem of Populus trichocarpa Cu has a role of cofactor in function of several dismutases (enzymes catalyzing formation of H2O2 from R.O.S.) and in laccases enzyme (Pilon et al. 2006). Many clones of P. Trichocarpa were multiplyed and grown up in MS addicted agargel with two different Cu concentrations (0.1 µM e 5 µM) to verify trough quantification of Cu-enzymes activity (western blot and native gel) if and how much these two Cu concentrations (the first closest to the limit of deficiency and the second pretty high but far from toxicity ), could affect Cu-enzymes activity. Once quantified activity of Cu-SODdepending on Cu concentration, a preliminary investigation on Laccases regulation was done. Because Laccases needs four Cu ions and because in a condition closest to Cu deficiency, cell inhibits all Cu requiring enzymes except that necessary to make photosintesis like plastocianin, we wanted verify if Laccases faith was exactly the same. Primers were drawn (RNA short sequences neded to make a Polimerase Chain Reaction in vitro ) to amplify the target sequence of a miRNA (RNA short sequences that, coupled with RISC complex, cut down mRNA inactivating it) (Yamasaky et al. 2007; Abdel Ghani et al 2008) and to obtain after an electrophoretic run, bands of different intensity, depending on the down regulation action made by cell. Preliminary results show different levels of expression for several kinds of laccase in stem and leaves.
Introduzione generale L’attività di ricerca svolta nel triennio 2007-2009 si colloca nell’ambito della fitodepurazione. Con questo termine si identifica una serie di tecniche (fitoestrazione, fitostabilizzazione, fitovolatilizzazione) basate sull’impiego di specie vegetali diverse (l’elenco delle quali è in continua evoluzione) ma accomunate dalla capacità di sopravvivere su substrati contaminati da diversi inquinanti prodotti dall’attività umana e di interagire con il substrato in modo tale, a seconda dei casi, da depauperarne il contenuto di inquinanti accumulandoli nei propri organi e/o liberandoli nell’atmosfera attraverso l’evapotraspirazione fogliare, oppure impedendone la lisciviazione. L’attitudine ad un’azione di fitorimedio varia fortemente da specie a specie e all’interno della stessa specie in base al corredo genetico . Relativamente alla capacità di rimozione di metalli pesanti, sono state individuate due classi di specie accumulatrici: Iperaccumulatrici : sono specie tipiche di suoli metalliferi, in grado di portare a termine il proprio ciclo vitale senza manifestare sintomi di deperimento dovuti all’alta concentrazione di metalli (Baker et al., 2000). Per essere definita iperaccumulatrice, una specie deve rientrare nei seguenti limiti inferiori di bioaccumulo: 100 mg/Kg s.s. di Cd, 1000 mg/Kg s.s di Pb, 10000 mg/Kg s.s. di Zn ; i ranges per quanto riguarda l’arsenico non sono ancora stati ben definiti (Baker and Brooks 1989, Baker et al., 2000). Tra le specie iperaccumulatrici le più rappresentative sono quelle appartenenti al genere Thlaspi, Arabidopsis halleri e Viola calamarina, Astragalus spp oltre a diverse specie appartenenti alle famiglie delle Cariophyllaceae, Fabaceae, Poaceae, Chenopodiaceae, Brassicaceae e Cyperaceae. Per quanto riguarda l’iperaccumulo di arsenico spicca Pteris vittata. Il limite delle specie iperaccumulatrici è la scarsa produzione di biomassa. Accumulatrici: a questo gruppo appartengono specie, ad habitus sia erbaceo che arboreo, in grado di ottenere buone concentrazioni di metalli e metalloidi nei propri organi, pur non arrivando a livello delle iperaccumulatrici, e una buona produzione di biomassa. Fra esse sono state individuate Brassica juncea, e il genere Salix. Le caratteristiche di queste accumulatrici le rendono idonee a programmi di disinquinamento a breve e medio termine, soprattutto per suoli poco o mediamente inquinati. La possibilità di avere una considerevole produzione di biomassa permette di pensare, come seconda fase, al reimpiego di questa per la produzione di energia ed il recupero dei metalli pesanti di interesse industriale ((Kabata-Pendias and Pendias, 1992 ; Pullford and Dickinson 2004 ; Paulson et al 2003; French et al 2005; Ebbs et al 1997 ; Ebbs et al 1998). Il lavoro triennale, suddiviso in diverse fasi, come descritto in seguito, si propone di approfondire la conoscenza su alcune delle specie suddette , sia dal punto di vista della risposta fisiologica sia , con un taglio maggiormente applicativo, dal punto di vista della valutazione di performaces di bioaccumulo al fine di sostituire, ove possibile, tecniche di bonifica invasive e costose con la fitodepurazione che, nelle sue diverse applicazioni, si dimostra piu’ rispettosa del territorio, anche dal punto di vista estetico e considerevolmente piu’ vantaggiosa economicamente. Prove di valutazione della capacita’ di accumulare metalli pesanti da parte di quattro specie di Salice (Salix spp) , di Phragmites australis e Brassica juncea. Date queste premesse, in collaborazione col dipartimento I.M.A.G.E. della Facoltà di ingegneria dell'Università di Padova, nell’ambito del PRIN 2005 ““Risanamento di sedimenti marini, lagunari e fluviali” sono state messe a punto delle prove sperimentali finalizzate a comprendere le potenzialità di Salix spp, di Brassica juncea e Phragmites australis nel mettere in atto un'azione di fitorimedio su sedimenti provenienti dal dragaggio della laguna di Venezia nella zona di porto Marghera. Il campionamento dei fanghi è stato effettuato in quattro siti (canale industriale nord, due punti del canale industriale ovest, bacino dell'Evoluzione), quindi i campioni sono stati catalogati e caratterizzati. In vista dell’allestimento di possibili impianti finalizzati al fitorisanamento dei fanghi dragati dall’area di Porto Marghera, sono state allestite delle prove sperimentali con l’intento di definire le potenzialità fitoestrattive di Salix matsudana, S. babylonica, S. alba e S. fragilis, Phragmites australis e Brassica juncea e valutarne quindi l’idoneità ad essere messe a dimora su questi sedimenti, anche in base alla capacità di sopravvivenza ed alla produzione di biomassa. I campioni provenienti dai 4 siti, sono stati miscelati tra loro ed in rapporto 1:1 con della sabbia di fiume, sia per ottenere un substrato con valori omogenei relativamente alle concentrazioni di inquinanti, sia per aumentare la capacità drenante di un substrato altrimenti totalmente asfittico. Prova su mesocosmo : Dopo test preliminari che hanno evidenziato l’impossibilita’ di condurre prove, ceteris paribus, anche su Salix Babylonica, Fragilis ed Alba, su Thypha latifolia e su Zea Mais, sono state allestite 7 vasche (2 dedicate a Phragmites australis, 2 a Salix Matsudana e 2 a Brassica juncea ed una priva di vegetazione, della capienza di 50 L (riempite fino a 35 L) ciascuna, munite di un tubo per il drenaggio del percolato alla base. Sul fondo delle vasche è stato depositato uno strato di argilla espansa e l’ingresso del tubo è stato protetto dall’intasamento con un filtro Le talee di salice ed i semenzali di brassica sono state messe a dimora con un piccolo pane di terriccio universale al fine di attutire gli effetti dello stress da trapianto e di permettere all’apparato radicale di accrescersi a sufficienza prima di esplorare il sedimento contaminato, mentre i rizomi di Phragmites hanno attecchito a diretto contatto col substrato oggetto di analisi. Dopo due mesi dall’inizio della prova, ad una delle vasche ospitanti la Phragmites e’ stato addizionato il chelante EDTA. Prove in idroponica : prendendo come riferimento le concentrazioni di 5 tra metalli pesanti riscontrati nell’analisi dei campioni di percolato (Ni,Cd, Zn, Cu, Pb,) e la concentrazione media del Na (intorno a 0,2 M) sono state allestite degli allevamenti in coltura idroponica con talee, oltre che di S. matsudana, anche di S. alba, S. babylonica , S. fragilis e di Brassica juncea. Per quanto riguarda i salici, la soluzione contenente inizialmente una soluzione nutritiva di tipo hoagland, è stata arricchita dai suddetti 5 metalli, in concentrazione pari a quella riscontrata nelle acque di percolazione. Per ogni specie di salice è stato allestito un beacker di controllo con sola soluzione nutritiva, un becker con soluzione nutritiva, più i metalli ed uno con le caratteristiche precedenti più NaCl a concentrazioni crescenti (da 0,05 M fino a 0,2 M). Per le brassiche sono stati allestiti 5 becker con 40 piantine ciascuno. Un beacker di controllo con soluzione nutritiva, due con concetrazione di metalli pari a quella del percolato, due con concentrazione di metalli pari al percolato più NaCl 0,05 M (aumentato fino a 0,2 M nel corso di 3 settimane). Alla fine del periodo di trattamento sono state separate e pesate parte aerea ed apparato radicale dei semenzali e ne sono stati analizzati i contenuti in metalli e Na. Prove su microcosmi : sono state allestite 5 taniche da 20 L ciascuna, dotate di rubinetto alla base e sistemate in cella climatica, tutte dotate di uno strato drenante di ghiaino alla base, un orizzonte costituito solo da sedimento ed uno, quello più superficiale, di terriccio universale. Quattro taniche hanno ospitato ciascuna tre talee (una specie per ogni tanica) e otto piantine di Paspalum vaginatum, la quinta tre talee di S. Babylonica e otto piantine di Paspalum. L’insediamento delle talee e della graminacea è durato 50 giorni. Nella settimana successiva alla messa a dimora dei S. Babylonica nella quinta tanica è stato aggiunto l’ EDDS, un chelante che ha lo scopo di rendere più biodisponibili i metalli pesanti presenti nel substrato. Studio dell’approfondimento radicale dei salici : per verificare la capacità delle quattro specie di salice, di esplorare il sedimento contaminato sono state allestite 24 bottiglie in pet da 2 L, di cui 16 riempite con lo stesso contenuto delle taniche e 8 (due per specie) riempite con del terreno proveniente dall’Azienda Sperimentale “L. Toniolo”. In ogni bottiglia è stata messa a dimora una talea di salice (6 bottiglie per specie). Al termine dei 50 giorni di prova condotti in camera di crescita, è stata asportata la parte aerea della talea, le bottiglie sono state congelate e poi segate in tre parti corrispondenti alla sezione contenente il terriccio e a due parti conteneti il sedimento. Tutte le radici presenti sono state estratte , lavate e pesate e sottoposte a scansione digitale. Risultati : Phragmites : azione efficace del chelante EDTA per quanto riguarda l’accumulo di Cd, Ni, Pb Zn e Na nei fusti di Phragmites, mentre differenze significative nei rizomi sono state riscontrate solo per Pb e Na. Nessuna differenza in termini di biomassa prodotta. Il chelante ha reso maggiormente disponibile nella soluzione circolante Cu e Zn anche se le concentrazioni restano molto basse. Salici nelle taniche in cella climatica : gli accumuli a livello fogliare non mostrano differenze significative tra le quattro specie non trattate. Mentre l’EDDS incrementa le prestazioni del babylonica rispetto a se stesso ed alle altre specie per quanto riguarda Cu, Ni, Pb e Zn mentre riduce la concentrazione di Na. A livello di fusti la suddetta differenza si esplica nelle concentrazioni di Cu, Zn e Na; questi ultimi risultano maggiormente accumulati dal babylonica sia con che senza chelante. A livello radicale il babylonica risulta ancora uno dei migliori accumulatori del lotto per quanto riguarda Na, Zn e Cd. Nessuna differenza ne tra specie ne tra presenza/ assenza di chelante per quanto riguarda il Ni. In un confronto tra questi salici ed il matsudana cresciuto piu’ a lungo e in condizioni di T , umidita’ e fotoperiodo variabili, a livello fogliare il salice cresciuto in mesocosmo presenta valori di Na significativamente piu’ alti degli altri salici, seguito dal matsudana cresciuto in cella, a conferma dell’atitudine di questa specie a traslocare piu’ facilmente il Na nella chioma. Anche riguardo Cd e Ni il matsudana di campo denuncia tra i valori piu’ elevati assieme al babylonica trattato con EDDS. Nei fusti, per Na ,Pb e Ni ci sono differenze significative in favore del S. matsudana di campo. A livello radicale il S. matsudana cresciuto in mesocosmo presenta valori significativamente piu’ alti rispetto alle prove in cella climatica ad eccezione del Na. Le prove in idroponica confermano, a livello fogliare che l’accumulo di Na compete fortemente con l’uptake dei metalli, in particolare nei confronti di Cd, Ni, Pb e Zn ; piu’ sfumata invece l’azione competitiva verso il Cu. Da rilevare, a livello di fusti le migliori performances di S. babylonica per Cd, Cu, Zn e Ni, nonostante si rilevi nel contenpo il primato nell’accumulo di Na. Anche a livello radicale il babylonica accumula piu’ delle altre specie per quanto riguarda Cd, Ni Zn e Na. La prova sullo sviluppo radicale mostra, nella comparazione col rispettivo controllo, che l’apparato radicale di S. babylonica risulta il meno sofferente tra le quattro specie (in accordo quindi con i dati di accumulo), mentre comparando le quattro specie cresciute sul sedimento, il Salix alba risulta avere l’apparato piu’ sviluppato in profondita’ e con i diametri minori , segno questo che potrebbe essere considerato di minor sofferenza, come riscontrato anche da Vamerali et al. 2008. L’allevamento in idroponica di Brassica juncea evidenzia differenze significative tra l’accumulo di metalli in presenza di Na rispetto all’accumulo in assenza di quest’ultimo. Le performances di accumulo rispetto alle brassiche cresciute su fango sono nettamente migliori, anche in presenza di Na , a testimonianza del fatto che A) l’idroponica non offre termini di paragone affidabili rispetto alle condizioni di campo B) probabilmente intervengono altri fattori, come la carenza di nutrienti, a condizionare l’accumulo di metalli e la produzione di biomassa che risulta bassa anche per la precocita’ della fioritura, sintomo della condizione di stress. Interazione del selenato e del molibdato con il trasporto e l’assimilazione di solfato in Brassica juncea Recentemente e’ stato individuato in Arabidopsis un trasportare (MOT1) con elevata affinita’ per il Mo (Tomatsu et al., 2007), ma si ritiene che le piante assorbano Mo anche attraverso i trasportatori del S poiche’ i due anioni hanno caratteristiche simili e potrebbero competere nell’occupare il sito attivo degli stessi trasportatori (Dudev e Lim 2004; Alhendawi et al 2005). Una volta all’interno della cellula, Mo puo’ interferire col metabolismo dello S divenendo substrato per le reazioni catalizzate dall’ ATP sulfurilasi (APS), come accade per il Se ma, a differenza di quest’ultimo non si riscontra la formazione di prodotti contenenti Mo derivanti da questa reazione (Reuveny, 1977). A causa del significativo impatto che l’applicazione di fertilizzanti a base di S puo’ avere sulla distribuzione di Se e Mo e sul loro accumulo nelle piante (Shinmachi et al., 2010), si e’ cercato di capire, in questo lavoro,quale sia l’interazione tra l’uptake di S e il Se e Mo in Brassica juncea. A questo scopo semenzali di Brassica juncea sono stati allevati con differenti combinazioni di S e Se o S e Mo. Gli esperimenti sono stati condotti nel breve periodo (24h) poiche’ selenato e molibdato sono stati somministrati ad alte concentrazioni (200 µM), le stesse del solfato in condizioni di normale apporto di S. Sono state condotte analisi relative all’accumulo di S, Se e Mo e ai paramentri di crescita. L’indice di tolleranza (% del peso fresco sul controllo) e il rapporto radici/fusti denuncia un maggiore stress per le piante cresciute in carenza di zolfo e in presenza di Se e Mo. Se e Mo sono risultati maggiormente assorbiti in carenza di S. Sia per quanto riguarda lo S totale , sia riguardo al ssolfato, la competizione con Se e Mo si nota solo tra le 6 e le 24 h di trattamento, mentre nel brevissimo periodo (entro 1 h) non si apprezzano cambiamenti significativi nell’assorbimento di S. Studio dei potenziali effetti del Selenio sulla tolleranza allo stress idrico da parte di Brassica juncea e Stanleya pinnata . Talune specie accumulatrici di Se (Brassica spp, Stanleya spp, Astragalus spp.) usano questa peculiarita’ per difendersi dai predatori (Freeman et al., 2007; Galeas et al. 2007 ; ) e recentemente si e’ visto che Brassica juncea , a differenza di quello che succede per altri elementi tossici o potenzialmente tossici, accumula selenio in grandi quantita’ anche nei fiori e nei semi, avvalorando l’ipotesi, per certe specie o sottospecie o addirittura per alcune popolazioni in via di speciazione, di un adattamento evoluzionistico nell’uso del selenio contro parassiti e predatori erbivori (Quinn C. et al., dati non ancora pubblicati).Su queste due specie sono state condotte prove su substrato ghiaioso e in idroponica in presenza (20 µM) e in assenza di Selenato di sodio. Il deficit idrico e’ stato applicato prima su substrato ghiaioso attraverso la mancata irrigazione, poi in idroponica attraverso l’aggiunta di polietilenglicol (PEG 10000), un composto organico che altera il Ψ idrico della soluzione nutritiva. Nei due esperimenti condotti in idroponica il potenziale e’ stato portato fino a -1.3 / 1.6 Mpa. Dalla misurazione della capacita’ fotosintetica sotto stress idrico, della biomassa e del Ψ idrico fogliare nei diversi esperimenti, si e’ arrivati alla conclusione che non vi e’ una evidente azione positiva del Se nei riguardi della tolleranza allo stress idrico se non per quanto riguarda la condizione di controllo (non stress) e di stress lieve (-0.5/0.6 Mpa). Questa azione, pur non marcata, si esplica nell’aumento di biomassa superiore in piante trattate con selenato rispetto a quelle non trattate in accordo con quanto riscontrato per semenzali di Triticum aestivum (Yao Xiaoqin et al. ; 2009). Studio delle potenzialita’ di Astragalus racemosus (iperaccumulatore di Selenio) e Astragalus convallarius (non accumulatore) nel ruolo di accumulatori di Nichel, Molibdeno, Cromo, Vanadio, Tungsteno, Arsenico, Tellurio e Selenio. Il genere Astragalus comprende diverse specie distribuite in america centro settentrionale, alcune delle quali adattate a vivere su suoli seleniferi e quindi in grado di sviluppare un’elevata tolleranza al Se, divenendo cosi’ iperaccumulatrici (Cowgill, 1990). Arsenico, Nichel Cromo, Vanadio, Tellurio, Tungsteno e Molibdeno sono tutti elementi la cui concentrazione nell’ambiente e’ aumentata a causa dell’attivita’ umana ( Bamhart 1997 ; Zarchinas et al 2004 ; Zoller et al. 1973 ; Gott and McCarthy 1966 ; ) . e l’obiettivo di questo studio e’ capire se gli adattamenti fisiologici nei confronti dell’accumulo di Se siano efficaci anche nei confronti di altri metalli pesanti e metalloidi, in particolare Cromo e Tellurio che presentano caratteristiche steriche simili al Selenio. Queste due specie di Astragalus sono state fatte germinare in piastra petri e quindi fatte crescere in camera di crescita per 3 mesi su substrato di agargel piu’ Murashige & Skooge e addizionato con sali degli elementi sopra indicati dosati in concetrazioni differenti in base al loro grado di tossicita’ (affinche’ le piante potessero crescere ed accumulare metalli senza patirne la tossicita’ fino a morirne troppo precocemente). I risultati hanno dimostrato che non sempre la specie iperaccumulatrice di Selenio ha le caratteristiche per tollerare l’accumulo anche di altri elementi (A. Convallarius si e’ dimostrato piu’ tollerante nell’accumulo di Vanadio). Studio degli effetti del Rame nella fisiologia di Populus trichocarpa ed in particolare sull’attivita’ della proteina Laccasi, coinvolta nella formazione della parete cellulare. Il Rame e’ coinvolto come cofattore, nel funzionamento di diverse dismutasi (proteine che trasformano i ROS in H2O2) oltre che essere cofattore per il funzionamento delle laccasi (Pilon et al. 2006). Allevando in agargel e moltiplicando diversi cloni di Populus trichocarpa generati a partire dallo stesso callo, con due diverse concentrazioni di Cu (0.1 µM e 5 µM) si e’ voluto verificare attraverso analisi dell’attivita’ proteica (western blot e native gel) se e quanto due concentrazioni di rame (una prossima al limite inferiore che ne decreta la carenza ed una piuttosto elevata ma ben entro i limiti di tossicita’), influenzino l’omeostasi cellulare. Una volta verificato la diversa intensita’ dell’attivita’ delle proteine in questione (MnSOD, Cu/ZnSOD, FeSOD, CCS ecc. In base alla concentrazione di rame fornita, si e’ passato ad uno studio preliminare dell’espressione della Laccasi in base alle due diverse concentrazioni di rame. Poiche’ la laccasi necessita anch’essa del Cu come cofattore (4 ioni Cu ) e poiche’ in uno stato di carenza o prossimo alla carenza di rame, la cellula inibisce l’espressione di tutte le proteine che richiedono rame e che non sono strettamente necessarie alla fotosintesi come invece lo e’ la plastocianina, si e’ voluto verificare se la laccasi subisse esattamente questo destino. Sono stati quindi disegnati dei primers (sequenze innesco per amplificare col metodo PCR il DNA retrotrascritto da RNA) che contemplassero l’amplificazione della sequenza bersaglio dei microRNA (sequenze brevi di RNA che in coppia col complesso proteico RISC tagliano e quindi inattivano l’RNA messaggero) (Yamasaky et al. 2007; Abdel Ghani et al 2008) in modo da avere, dopo la corsa elettroforetica su gel di agarosio, bande di intensita’ diversa in base all’azione di downregulation operata o meno dalla pianta. I risultati preliminari mostrano diversi livelli di espressione per diversi tipi di laccasi analizzati presenti nel fusto e nelle foglie,

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O estudo de elementos essenciais e contaminantes nas amostras biológicas é de grande importância visto que a variação da concentração destes é um parâmetro para detecção de diversas doenças e distúrbios metabólicos provocados pela exposição a substâncias tóxicas e medicamentos. O objetivo deste trabalho foi propor um método analítico visando avaliar o efeito da furosemida (diurético de alça) sobre a composição mineral (Mg, Cu, Fe, Se, Zn, Cd e Pb) em amostras biológicas (fígado, rim, coração, pulmão e soro) de ratos Wistar por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Para a decomposição das amostras foi utilizado um procedimento por via úmida, com adição de ácido nítrico e peróxido de hidrogênio, empregando forno de microondas com cavidade. As figuras analíticas de mérito (precisão, limites de detecção (LOD) e quantificação (LOQ) e efeito de matriz) foram determinadas para o procedimento proposto. A exatidão foi verificada com material de referência certificado fígado bovino NIST 1577b e por comparação com método de referência da AOAC (Association of Official Analytical Chemists). O procedimento proposto foi aplicado para avaliação dos efeitos da furosemida sobre a composição corporal de elementos essenciais e contaminantes de ratos Wistar. Os dados para Se, Cd e Pb foram abaixo do LOQ, sendo necessário a utilização de técnicas mais sensíveis como GF AAS e ICP-MS para a quantificação desses elementos em amostras biológicas. Em relação ao comportamento dos minerais nas amostras biológicas estudadas, o Cu, nas amostras biológicas dos ratos machos, este apresenta uma redução no fígado, rim e coração, mantendo-se constante no pulmão. Nas fêmeas há um aumento no fígado e redução no rim, coração e pulmão. Para o Fe, o comportamento é semelhante entre machos e fêmeas, com redução no fígado, rim e soro e aumento no coração e pulmão. O Mg apresenta uma constância no fígado e pulmão, redução no rim, coração e aumento no soro para machos, enquanto para fêmeas, em fígado e rim permanecem constantes e há redução no coração, pulmão e soro. Já o Zn reduz no fígado e rim dos machos e se mantém constante no coração e pulmão, sendo o inverso para as fêmeas. Foi encontrando como resultados uma extração dos elementos Mg, Cu e Zn em todos os tecidos biológicos estudados em uma magnitude de 16,8; 15,1 e 6,4 % para ratos machos e 13,0; 16,5 e 8,1 % para fêmeas, após a administração da furosemida em todos os animais estudados. O Fe apresentou um aumento de 21,8% e 5,1%, em todos os tecidos biológicos estudados, para ratos machos e fêmeas respectivamente, concluindo que a furosemida não traz prejuízos para a saúde com relação à perda de elementos essenciais
The study of essential elements and contaminants in biological samples is of great importance since the variation of the concentration of these is a parameter for the detection of various diseases and metabolic disorders caused by exposure to toxic substances and medicines. The aim of this study was to propose an analytical method to evaluate the effect of furosemide (loop diuretic) on the mineral composition (Mg, Cu, Fe, Se, Zn, Cd and Pb) in biological samples (liver, kidney, heart, lung and serum) of rats by optical emission spectrometry with inductively coupled plasma (ICP OES). For decomposition of the samples we used a procedure by wet, with the addition of nitric acid and hydrogen peroxide, using a microwave cavity. The analytical figures of merit (precision, limit of detection (LOD) and quantification (LOQ) and matrix effect) were determined for the proposed procedure. The accuracy was checked with certified reference material NIST 1577b bovine liver and by comparison with reference method AOAC (Association of Official Analytical Chemists). The proposed procedure was applied to assess the effects of furosemide on body composition of essential elements and contaminants in rats. The data for Se, Cd and Pb were below the LOQ, necessitating the use of more sensitive techniques such as GF AAS and ICP-MS for quantification of these elements in biological samples. As for the behavior of minerals in biological samples studied, the Cu in biological samples from male rats, this presents a reduction in the liver, kidney and heart, remaining constant in the lung. In females there is an increase in the liver and reduction in kidney, heart and lung. For Fe, the behavior is similar between males and females, with a reduction in the liver, kidney and serum and increased heart and lung. Magnesium has a constancy in the liver and lung, reduction in kidney, heart and an increase in serum for males as for females, liver and kidney remain constant and there is a reduction in heart, lung and serum. Already reduces the Zn in the liver and kidney of males and remained constant in the heart and lungs, and the converse for females. Was found as a result of the extraction elements Mg, Cu and Zn in all biological tissues studied in a magnitude of 16.8, 15.1 and 6.4% for males and 13.0, 16.5 and 8.1 % for females, after administration of furosemide in all animals studied. Fe showed an increase of 21.8% and 5.1% in all biological tissues studied, for males and females respectively, concluding that furosemide does not bring harm to health in relation to loss of essential elements

L'objectif général de cette thèse est de mieux comprendre l'influence d'anciens sites miniers sur la contamination en métaux (Cd, Hg, Tl, Pb, Zn) et métalloïdes (As, Sb) de l'hydrosystème aval. Une attention particulière a été portée à l'antimoine (Sb), dont le comportement dans les cours d'eau contaminés par les drainages miniers reste mal connu et dont la signature isotopique pourrait permettre de tracer différentes sources et processus. Le site d'étude est le bassin des Gardons dans le Gard ; ce cours d'eau Cévenol draine de nombreux sites miniers abandonnés (Pb, Zn, Sb, charbon). L'enrichissement en métaux et métalloïdes a été étudié dans les sédiments actuels et anciens du bassin des Gardons. Un historique de la contamination métallique a été reconstitué à l'aide d'une archive sédimentaire. Les sources prépondérantes de métaux et métalloïdes dans les sédiments ont été déterminées ainsi que la mobilité potentielle de ces éléments vers la phase aqueuse. En complément, les variations de concentrations en métaux et métalloïdes dans les phases dissoute et particulaire ont été étudiées lors d'un épisode de crue grâce à un échantillonnage à haute résolution temporelle. Dans leur ensemble, les résultats montrent que les anciennes mines du bassin des Gardons contribuent à l'enrichissement en métaux et métalloïdes du cours d'eau aval, particulièrement en période de crue. Plus spécifiquement, le comportement de l'antimoine a été étudié dans un affluent du Gardon impacté par du drainage minier acide en aval de l'ancienne mine de Carnoulès et la composition isotopique de l'antimoine a été déterminée dans des eaux prélevées sur le bassin des Gardons et de l'Orb amont, après mise au point d'un protocole de purification/pré-concentration de Sb. Les résultats mettent en évidence le potentiel des isotopes de l'antimoine pour tracer l'origine de cet élément et les processus qu'il subit au cours de son transfert dans les cours d'eau impactés par du drainage de mine
The overall objective of this thesis was to improve understanding of the influence of former mining sites on metal (Cd, Hg, Tl, Pb, Zn) and metalloid (As, Sb) contamination of the downstream hydrosystem. A special care was given to antimony (Sb), its behavior in mining-impacted streams remains poorly known and its isotopic signature could be usefull to track sources and processes. The study site is the Gardon River watershed in the south-east of France which drains many abandoned mining sites (Pb, Zn, Sb, coal). Metal and metalloid enrichment was studied in current and historical sediments of the Gardon River watershed. A sedimentary archive was used to investigate past metal contamination history. The prevailing metal and metalloid sources in sediments were determined together with the potential mobility of these elements toward the aqueous phase. In addition, dissolved and particulate metal and metalloid concentration variations were studied during a flood event using a high temporal resolution sampling. Altogether, the results suggest that former mining sites of the Gardon River watershed contribute to metal and metalloid enrichment of the downstream hydrosystem, especially during floods. More specifically, antimony behavior was investigated in a tributary of the Gardon River which is impacted by acid mine drainage originating from the disused Carnoulès mine and antimony isotopic composition was determined in waters collected in the Gardon River watershed and in the Upper Orb River after developing a protocol for preconcentrating and purifying Sb. The results highlight the potential of antimony isotopes to track the origin of this element and the processes that it undergoes during its transfer in streams impacted by mine drainage

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CAPES
As macroalgas estão sendo bastante utilizadas com êxito no monitoramento da qualidade ambiental. Diante da crescente contaminação na Baía de Todos os Santos (BTS), Bahia, Brasil, neste trabalho foram determinadas as concentrações de elementos traço, micro e macro em macroalgas e fanerógama marinhas coletadas em vários pontos da baía, visando estudar a distribuição dos elementos. As macroalgas estudadas foram: Acanthophora spicifera, Bostrychia montagnei, Dictyopteris jamaicensis, Padina spp., Sargassum spp., Ulva lactuca, Bryopsis plumosa, Caulerpa racemosa, Caulerpa scalpelliformis, Codium isthmocladum e Penicillus capitatus. A fanerógama marinha foi Halodule wrightii. As amostras foram coletadas em: Salinas da Margarida, Ilha de Bimbarras (São Francisco do Conde), Ilha de Maré (Salvador), Praia de Caboto (Candeias), Praia da Ribeira (Salvador) e Praia da Penha (Vera Cruz – Ilha de Itaparica). Os períodos de coleta seguiram a sazonalidade (períodos seco e chuvoso) e os elementos estudados foram As, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Ni, P, Pb, Sb, Sn, Se, Sr, V e Zn. As amostras foram submetidas à digestão em forno de micro-ondas com cavidade, após otimização de parâmetros, e os analitos determinados em espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) e espectrometria de massas com plasma indutivamente acoplado (ICP-MS). Foi observado que alguns elementos se destacaram em determinadas localidades, em ambos os períodos, tais como, em μg g-1: Cd (0,140-6,13) e Zn (6,63-45,9) em Bimbarras; Li (0,233-10,1) e As (2,29-54,2) em Praia da Penha; Cd (0,293-3,25) em Salinas da Margarida; Li (1,92-9,86), Pb (6,28-8,58), V (14,1-21,2), Cr (1,45-7,42) e Cu (70,1-126) em Caboto; Ni (1,95-17,3) na praia da Ribeira; e Li (0,980-11,4), Pb (1,32-8,05), Cu (13,1-57,8) e Zn (20,1-56,6) em Ilha de Maré. Os táxons que apresentaram maiores capacidades de acumulação para a maioria dos elementos estudados foram Sargassum spp, Caulerpa racemosa e Padina spp. No estudo da variação da concentração dos analitos quanto à variação da intensidade de chuvas, foi observado que apenas os elementos Li e Co exerceram influência significativa sobre os resultados.
Salvador

Les Technosols comprennent les sols soumis à une forte pression anthropique et en particulier les sols influencés par les matériaux d'origine humaine. Dans ce contexte, les sites miniers abandonnés peuvent souvent contenir une grande quantité de déchets transformés enrichis en métaux et métalloïdes. En comparaison avec les sols naturels, la singularité des Technosols miniers correspond à leur matériel parental constitués de déchets minéraux de granulométrie fine. Contrairement à leurs homologues peu anthropisés, les Technosols sont encore assez mal connus. L'objectif global de cette étude est d'approfondir les connaissances des processus pédogénétiques des Technosols développés naturellement à partir de déchets miniers de façon à mieux anticiper la réhabilitation de ces sites. Ainsi, différents profils ont été échantillonnés correspondant respectivement à d’anciennes exploitations de W, Pb-Ag, Sn et Au. Leurs fonctionnements pédologiques ont dès lors été étudiés afin de déterminer les liens potentiels et les leviers guidant leur évolution. Cette étude préliminaire correspond à une image contemporaine de ce que peut donner une réhabilitation naturelle (par simple formation de solum après végétation spontanée) pour une durée d’environ 75 ans en moyenne. Dans un second temps plusieurs techniques de réhabilitation ont été étudiés respectivement: (i) la phytoremédiation par culture du Douglas ainsi que (ii) la revalorisation des déchets par synthèse de géopolymères enrichis en déchets miniers
The Technosols include soils subject to strong anthropogenic pressure and particularly to the soil influenced by human-made materials. In this context, abandoned mine sites can contain a large amount of transformed waste materials often enriched with metals and metalloïds. Compared to natural soils, the singularity of mining Technosols naturally developed from mining waste corresponding to their parental material made by fine-grained mineral waste. Unlike their poorly anthropized homologous, Technosols are not enough well known. So, the overall objective of this study is to increase knowledge of soil processes of Technosols after spontaneous vegetation impact. Thus, different profiles were sampled respectively corresponding to different abandoned mine exploitation type: W, Pb-Ag, Sn and Au. Their pedogenic way have therefore been studied to determine potential linkages and levers guiding their evolution. This preliminary study is based on the contemporary picture of a natural rehabilitation (by simple solum formation) for a period of about 75 years on average. Secondly several rehabilitation techniques have been studied respectively: (i) the phytoremediation by growing Douglas plant and (ii) the reused of waste by mine sediment based geopolymer synthesis

Les conséquences des activités industrielles passées, et notamment métallurgiques, persistent encore aujourd'hui. C'est le cas dans l'actuel Parc National des Calanques, qui abrite l'ancienne fonderie de plomb de l'Escalette (sud-est de Marseille). Ainsi, plus de 80 ans après la fermeture de cette usine, une contamination importante et étendue en éléments traces métalliques et métalloïdes (ETMM) est présente. Les objectifs de cette thèse ont été de contribuer à l'évaluation de la contamination diffuse en ETMM des sols des Calanques situés aux alentours du site industriel abandonné de l'Escalette. Dans un but futur de restauration écologique, solution adaptée dans le contexte particulier de la zone de pollution diffuse, située dans le Parc National des Calanques, les capacités d'accumulation et les mécanismes de tolérance d'une espèce autochtone, le romarin (Rosmarinus officinalis) ont été étudiés. Ainsi, cette étude a permis de mettre en évidence quelques mécanismes de tolérance aux ETMM certainement mis en jeu dans le cas du romarin. Les résultats montrent que le romarin pourrait être un candidat intéressant pour la phytostabilisation aux vues de sa capacité d'accumulation des ETMM dans les racines, ainsi que sa résistance à des niveaux de contamination très élevés
Past industrial activities, particularly metallurgical one, have current environmental consequences. As an example, the former lead smelter from l'Escalette (South-East Marseille, France) in the National Park of Calanques lead to an important environmental pollution of its surroundings. Thus, more than 80 years after its activity ceased, a trace metal and metalloide (TMM) diffuse pollution is still present. This PhD study aimed to contribute to the assessment of the diffuse contamination levels by TMM of the Calanque's soils around the former lead smelting factory. Aiming at identifying an adapted solution of ecological restoration of the areas with diffuse pollution located in the National Park of Calanques. Accumulation abilities and tolerance mechanisms of a native plant species, rosemary (Rosmarinus officinalis), were studied. In order to achieve this, in situ and ex situ assays were performed. TMM concentrations in rosemary organs (leaves, stems, roots) and some stress phytometabolites were assessed. Moreover, the role of mycorrhizal symbioses in rosemary tolerance was evaluated

Les interactions entre plantes dans les milieux impactés par les métaux/métalloïdes dépendent de nombreux facteurs et sont encore très peu connues. Tout d’abord elles semblent dépendre du niveau de pollution métallique du milieu, mais aussi des stratégies fonctionnelles végétales des plantes interagissant. D’autre part, les plantes peuvent avoir plusieurs types d’effets sur leur environnement proche, effets s’exprimant à des temporalités différentes. En effet, les plantes ont un effet immédiat via leur canopée et racines sur les ressources et le microclimat à proximité. Aussi, au cours d’une saison de végétation, les plantes peuvent avoir des effets liés à la production de la litière et sa décomposition dans les sols sous leur canopée. A plus long-terme, lorsque ce cycle de production/décomposition est répété au fil des années, les plantes vont avoir un effet lié à la dynamique de la matière organique dans les sols. Dans cette thèse, notre objectif principal était de différencier ces effets, et de comprendre comment les stratégies fonctionnelles végétales des plantes pouvaient influencer les différents effets en jeu le long de gradients de pollution métallique. Nous avons étudié ces effets pendant trois années (entre 2020 et 2022) dans une ancienne vallée minière des Pyrénées Ariégeoises (Sentein, France). Dans cette zone d’étude, nous avons étudié les interactions entre plantes par des méthodes observationnelles et de transplantations de cibles avec contrôle de la présence de canopée et/ou de la litière des plantes, sur trois sites d’étude : un terril avec une pollution homogène et deux zones de résidus miniers avec des pollutions hétérogènes créant un gradient de pollution. Le long des gradients étudiés, les effets de canopée et de prélèvement racinaire ont suivi l’Hypothèse du Gradient de Stress, passant de la compétition à la facilitation avec l’augmentation de la pollution. Cette facilitation était d’autant plus forte que les espèces produisant l’effet sont dites « exploitatrices » (en lien avec l’exploitation des ressources du sol et Leaf Economic Spectrum), et bénéficiait le plus aux plantes les moins tolérantes aux métaux. Les effets positifs étaient surtout liés à l’amélioration des conditions microclimatiques lors d’épisodes chauds et secs en été. Concernant les effets liés à la production et décomposition des litières, des effets négatifs sur les plantes cibles ont été démontrés, suggérant des effets dits d’allélopathie élémentaire, et liés à la forte concentration en éléments métalliques dans les litières en décomposition. Ces effets négatifs de litière étaient maximums dans les milieux les moins pollués où les plantes métallophytes accumulatrices (qui ont des fortes teneurs en métaux dans leurs feuilles) et les plantes moins tolérantes aux métaux interagissaient. Ils étaient particulièrement marqués pour les cibles sensibles à la pollution métallique. Les résultats de cette thèse donnent des pistes potentielles pour utiliser la facilitation dans un cadre de phyto-management de milieux pollués par les métaux/métalloïdes, en prenant en compte explicitement les stratégies fonctionnelles végétales des plantes en interactions et le niveau de pollution en jeu. Des résultats obtenus pendant la canicule de 2022 nous donnent aussi une bonne vision des évolutions attendues des différents effets impliqués dans les interactions entre plantes dans les écosystèmes métallifères dans un contexte de changement climatique
Plant-plant interactions have been overlooked in metal/metalloids-impacted environments and are likely driven by several factors whose influence is barely known. First, plant-plant interactions depend on the level of metal pollution, but also on the functional plant strategies of the interacting plants. Furthermore, plants can have several type of effects on their immediate environment, acting at different timescales. Plants canopy and roots have an instantaneous influence on the microclimate and available resources in their immediate vicinity. Then, during a growing season, the production of litter and its decomposition beneath their canopy can influence soil chemical and physical properties. In the longer term, when this cycle of litter production/decomposition is repeated over the years, the dynamics of the organic matter will influence soil conditions even more. In this thesis, our main objective was to delineate these effects, and to understand how plant functional strategies can influence these various effects along metal pollution gradients. We studied these effects during three consecutive years (from 2020 to 2022) in a former mining valley in the French Pyrenees (Sentein, Ariège, France). In this area, we studied interactions between plants using observational and target transplantation methods controlling for the presence of plant canopy and/or plant litter, in three study sites: a slag heap with homogeneous pollution and two mine tailings areas with heterogeneous pollution creating a gradient of pollution. Along these gradients, short-term canopy and root-uptake effects followed the Stress Gradient Hypothesis, switching from competition to facilitation as pollution increased. This facilitation was stronger when the species producing the effect were acquisitive (in relation with soil resources and the Leaf Economic Spectrum), and benefits more the low metal-tolerant plants. These positive effects were mainly due to the improvement of micro-climatic conditions during hot and dry episodes in summer. Concerning the effects linked to litter production and decomposition, negative effects on target plants were found, suggesting the so-called “elemental allelopathic” effects, in relation with the high concentration of metallic elements in the decomposing litter. These negative litter effects were more important in the least polluted environments, where metal-accumulating metallophyte plants (which have high concentration of metals in their leaves) and less metal-tolerant plants interacts. They were particularly marked for targets sensitive to metal pollution. The results of this thesis give important perspectives regarding the use of facilitation for the phyto-management of metals/metalloids-polluted environments, given that the functional strategies of interacting plants and the level of pollution involved are explicitly considered. Additionnaly, the results obtained during the 2022 heatwave provide useful insights regarding the expected evolution of the different effects driving plant interactions in metalliferous ecosystems in a climate change context

La biosurveillance humaine permet aujourd’hui d’évaluer notre exposition aux produits chimiques par la mesure soit des substances elles-mêmes, soit de leurs métabolites ou marqueurs d'effets sur la santé, à partir des fluides corporels ou des tissus. Les informations recueillies dans le cadre d’enquêtes épidémiologiques renseignent sur l'exposition humaine et constituent des bases précieuses dans la recherche des relations exposition-réponse chez les humains. Les travaux de cette thèse s’inscrivent dans le cadre de l’enquête transversale IMePoGe conduite entre 2008-2010 dans la région Nord–Pas-de-Calais (au nord de la France), incluant 2000 résidents adultes âgés de 20 à 59 ans, et visant à quantifier les niveaux d’imprégnation de la population à 14 métaux et métalloïdes (aluminium, antimoine, arsenic total, béryllium, cadmium, cobalt, chrome, mercure, manganèse, nickel, plomb, thallium, vanadium, zinc) choisis pour leurs effets toxiques et la fréquence de l’exposition professionnelle et environnementale. Les objectifs spécifiques de cette thèse étaient, tout en portant une attention particulière au plomb et au cadmium, deux métaux néphrotoxiques connus dans la littérature : i) d’établir la distribution de l’imprégnation aux métaux et métalloïdes dans la population du Nord de la France et de comparer le niveau régional d’imprégnation avec les données nationales et internationales ; ii) d’identifier les facteurs majeurs de variation de l’imprégnation et les sources d’exposition au plomb et au cadmium dans la population générale ; iii) d’étudier la relation entre la variation du débit de filtration glomérulaire et les niveaux d’imprégnation aux métaux. Globalement, les concentrations sanguines et urinaires de la plupart des métaux et métalloïdes étaient plus élevées que celles rapportées dans l’enquête nationale nutrition santé conduite sur la même période dans la population française, à l’exception du vanadium urinaire et du plomb sanguin. La plombémie moyenne régionale (moyenne géométrique) était de 18,8 μg/L. De nombreuses sources d’exposition au plomb existaient dans la population et étaient à la fois d’origine professionnelle, environnementale et alimentaire. Pour ce qui est du cadmium, le tabagisme se présentait comme la principale source d’exposition récente ou chronique au métal : la cadmiémie moyenne, reflet de l’exposition récente, était de 0,39 μg/L et passait de 0,26 μg/L chez les non-fumeurs à 0,84 μg/L chez les fumeurs ; la cadmiurie moyenne, reflet de l’exposition chronique, était de 0,37 μg/L (0,33 μg/g créatinine) et passait de 0,33 μg/L (0,29 μg/g créatinine) chez les non-fumeurs à 0,46 μg/L (0.37 μg/g créatinine) chez les fumeurs. Enfin, dans le cadre de l’étude de la relation entre l’imprégnation aux métaux et le débit de filtration glomérulaire, notre étude a montré que la prise en compte de la co-exposition à d’autres métaux et métalloïdes potentiellement néphrotoxiques bouleversait considérablement les associations antérieures jusqu’ici rapportées spécifiquement avec le plomb et le cadmium, dans le cadre de faibles niveaux d’imprégnation en population générale
Human Biomonitoring allows us to evaluate our exposure to chemicals by measuring substances themselves or their metabolites or markers of health effects, from body fluids or tissues. The information collected through epidemiological surveys provide information on human exposure and are valuable databases in the research of exposure-response relationships in humans. This thesis is part of the cross-sectional IMePoGe survey conducted between 2008-2010 in the Nord–Pas-de-Calais region (in northern France), including 2,000 adult residents aged 20 to 59 years old, and aimed to quantify the impregnation levels of the population to 14 metals and metalloids (aluminum, antimony, total arsenic, beryllium, cadmium, cobalt, chromium, mercury, manganese, nickel, lead, thallium, vanadium, zinc) chosen for their toxic effects and the frequency of occupational and environmental exposure. The specific objectives of this thesis were, which a special interest for lead and cadmium, two nephrotoxic metals known in the literature: i) to establish the distribution of impregnation metals into the northern population of France and compare the exposure regional level to metals and metalloids with the national and international data; ii) to identify the major factors of variation of the impregnation and the sources of exposure to lead and cadmium in the general population; iii) to study the relationship between the change in glomerular filtration rate and the impregnation levels to metals. Overall, blood and urinary concentrations of most metals and metalloids were higher than those found in the national nutritional health survey conducted during the same period in the French population, with the exception of urinary vanadium and blood lead. The regional mean of blood lead level (geometric mean) was 18.8 μg/L. Several sources of lead exposure existed in the population and were link to the occupational, environmental and consumption parameters. Regarding cadmium, smoking was the main source of recent or chronic exposure to metal: the geometric mean of blood cadmium, reflecting a recent exposure, was 0.39 μg/L and increased from 0.26 μg/L in non-smokers to 0.84 μg/L in smokers; the geometric mean of urinary cadmium, reflecting the chronic exposure, was 0.37 μg/L (0.33 μg/g creatinine) and increased from 0.33 μg/L (0.29 μg/g creatinine) in non-smokers to 0.46 μg/L (0.37 μg/g creatinine) in smokers. Finally, as part of the study of the relationship between the metal levels and the glomerular filtration rate, our study showed that taking into account the multiple exposure to the other potentially nephrotoxic metals and metalloids upset considerably the previous associations specifically reported with lead and cadmium, in the context of low levels exposure in the general population

L’impact anthropique sur les cours d’eau a significativement augmenté suite à la révolution industrielle engagée par les pays occidentaux. Ainsi, les modifications de la géomorphologie des cours d’eau pour le stockage de l’eau et la navigation, la conversion des surfaces à des fins agricoles, industrielles et d’urbanisation illustrent cette pression environnementale, qui se traduit, en autre, par une augmentation de rejets de divers contaminants dans les compartiments environnementaux et notamment les rivières. Une part de ces rejets peut donc se retrouver dans les matières en suspension, considérées alors comme des puits de stockage, qui transitent dans les rivières. Les aménagements des rivières et notamment la construction de barrages favorisent alors la sédimentation de ces particules contaminées au cours du temps. Ces sédiments d’origines anthropiques, également appelés legacy sediments, sont donc les témoins des activités anthropiques et permettent de reconstruire les trajectoires temporelles des contaminations au sein des bassins versants. L’Eure, affluent majeur de l’estuaire de Seine, a connu d’importantes pressions anthropiques depuis le vingtième siècle. La reconstruction temporelle des pressions anthropiques a nécessité l’association de différentes approches méthodologiques : (i) une analyse diachronique des modifications morphologiques de la rivière a été menée, conjointement à (ii) une analyse de la dynamique sédimentaire et de la nature des dépôts sédimentaires par couplage de méthodes géophysiques, sédimentologiques et géochimiques, et à (iii) la mise en place d’un réseau de suivi du comportement hydro-sédimentaire avec un échantillonnage en continu des matières en suspensions. De profondes modifications géomorphologiques se sont produites en aval du bassin versant, avec pour principales conséquences un exutoire déplacé d’une dizaine de kilomètres en direction d’un barrage et la formation d’annexes hydrauliques favorisant l’accumulation de sédiments dès les années 1940. Ceux-ci ont permis de montrer que le bassin versant de l’Eure avait connu d’importantes contaminations dont les conséquences sont encore enregistrées malgré l’arrêt des activités ou usages. Les tendances temporelles des éléments traces métalliques et métalloïdes ont montré de fortes contaminations en As dans les années 1940 et des contaminations d’origines industrielles en Cr, Co, Ni, Cu, Zn, Ag et Cd durant les années 1960–1970, ainsi que des contaminations en Sb et Pb en 1990–2000. Ces dernières sont toujours enregistrées malgré l’arrêt des activités responsables des rejets, comme l’ont attesté les résultats issus des matières en suspension actuellement collectées dans le cours d’eau. A l’instar d’une majorité des métaux traces, les contaminants organiques, tels les HAPs, ont montré d’importantes contaminations durant les années 1940–1960, dont les signatures indiquent une origine majoritairement pyrogénique. Les PCBs ont montré des contaminations importantes lors de la période 1950–1970, en lien avec la production et les usages nationaux de mélanges composés en majorité de congénères faiblement chlorés. Enfin, l’intérêt porté à une troisième famille de contaminants organiques persistants, les pesticides organochlorés, a montré l’utilisation de lindane et du DDT notamment lors de la période 1940–1970, et a mis en avant d’une part une utilisation post-interdiction du lindane et d’autre part la présence d’un métabolite du DDT plusieurs décennies après l’arrêt d’utilisation de ce dernier, en lien avec l’augmentation de l’érosion des sols cultivés
The anthropogenic impact on rivers has significantly increased following the industrial revolutioninitiated by Western countries. Thus, changes in the geomorphology of rivers for water storage andnavigation, the conversion of land for agricultural, industrial and urbanization purposes illustrate thisenvironmental pressure, which results, among other things, in an increase in discharges of variouscontaminants into environmental compartments, particularly rivers. Therefore, part of these dischargescan end up in suspended particulate matter, which is then considered as storage wells, which transit inrivers. River development, particularly the construction of dams, encourages the sedimentation of these contaminated particles over time. These sediments of anthropogenic origin, also called legacy sediments, are therefore witnesses to human activities and make it possible to reconstruct the temporal trajectories of contamination within watersheds. The Eure River, a major tributary of the Seine estuary, has experienced significant anthropogenic pressures since the twentieth century. The temporal reconstruction of anthropogenic pressures has required the combination of different methodological approaches: (i) a diachronic analysis of the morphological modifications of the river was carried out, in conjunction with (ii) an analysis of the sedimentary dynamics and the nature of the sediment deposits by coupling geophysical, sedimentological and geochemical methods, and (iii) the setting up of a network for monitoring the hydro-sedimentary behaviour with continuous sampling of suspended particulate matter. Significant geomorphological changes have occurred in the lower reaches of the watershed, with the main consequences being an outlet moved some ten kilometres in the direction of a dam and the formation of hydraulic annexes favouring the accumulation of sediments as early as the 1940s. These made it possible to show that the Eure River watershed had experienced significant contamination, the consequences of which are still being recorded despite the cessation of activities or uses. The temporal trends of trace metal and metalloid elements showed strong contaminations in As in the 1940s and contaminations of industrial origin in Cr, Co, Ni, Cu, Zn, Ag and Cd in the 1960s and 1970s, as well as contaminations in Sb and Pb in 1990–2000. The latter are still recorded despite the cessation of the activities responsible for the discharges, as evidenced by the results from the suspended particulate matter currently collected in the river. Like most trace metals, organic contaminants such as PAHs showed significant contamination during the 1940–1960s, with signatures indicating a predominantly pyrogenic origin. PCBs showed significant contamination during the period 1950–1970, in connection with the production and national uses of mixtures composed mainly of low chlorinated congeners. Finally, interest in a third family of persistent organic contaminants, organochlorine pesticides, showed the use of lindane and DDT, particularly during the 1940–1970 period, and highlighted the post-ban use of lindane and the presence of a metabolite of DDT several decades after the cessation of its use, in connection with the increase in erosion of cultivated soils

Im Bereich der industriellen Metallurgie und Kristallzüchtung treten bei zahlreichen Anwendungen, wo magnetische Wechselfelder zur induktiven Beeinflussung von leitfähigen Werkstoffen eingesetzt werden, auch Strömungen mit freier Oberfläche auf. Das Anwendungsspektrum reicht dabei vom einfachen Aufschmelzen eines Metalls in einem offenen Tiegel bis hin zur vollständigen Levitation. Auch der sogenannte RGS-Prozess, ein substratbasiertes Kristallisationsverfahren zur Herstellung siliziumbasierter Dünnschichtmaterialien, ist dafür ein Beispiel. Um bei solchen Prozessen die Interaktion von Magnetfeld und Strömung zu untersuchen, ist die numerische Simulationen ein wertvolles Hilfsmittel. Für beliebige dreidimensionale Probleme werden entsprechende Berechnungen bisher durch eine externe Kopplung kommerzieller Programme realisiert, die für Magnetfeld und Strömung jeweils unterschiedliche numerische Techniken nutzen. Diese Vorgehensweise ist jedoch im Allgemeinen mit unnötigem Rechenaufwand verbunden. In dieser Arbeit wird ein neu entwickelter Methodenapparat auf Basis der FVM vorgestellt, mit welchem sich diese Art von Berechnungen effizient durchführen lassen. Mit der Implementierung dieser Methoden in foam-extend, einer erweiterten Version der quelloffenen Software OpenFOAM, ist daraus ein leistungsfähiges Werkzeug in Form einer freien Simulationsplattform entstanden, welches sich durch einen modularen Aufbau leicht erweitern lässt. Mit dieser Plattform wurden in foam-extend auch erstmalig dreidimensionale Induktionsprozesse im Frequenzraum gelöst.

Les hydrocarbures pétroliers sont expédiés et utilisés dans pratiquement toutes les parties du monde et sont devenus l’un des contaminants parmi les plus communs et les plus répandus dans les sols. Les éléments traces sont parfois associés aux hydrocarbures, ce qui peut augmenter la toxicité d’un site, compliquer les voies possibles de remédiation, et augmenter les coûts de traitements traditionnels. Dans les régions nordiques, où des déversements sont recensés dans de nombreux sites, le temps de nettoyage des contaminants et les coûts des méthodes d’assainissement traditionnelles peuvent s’avérer considérablement plus élevés que dans les régions tempérées. Des recherches alternatives visant une remédiation plus rapide et moins coûteuse, adaptée à des climats subarctiques, sont nécessaires et l’utilisation de plantes et champignons indigènes à l’écosystème local sont des approches prometteuses. En parallèle, les gouvernements de multiples pays visent à réduire les émissions de gaz à effet de serre, notamment par la réduction des déchets putrescibles voués à l’enfouissement. En utilisant ces matières résiduelles fertilisantes obtenues localement dans le processus de décontamination, une opportunité se présente pour valoriser ces matières tout en décontaminant des sites. Cette recherche doctorale vise à développer des méthodes de bioremédiation adaptées aux conditions locales, avec des intrants indigènes aux régions d’étude, pour des sols contaminés aux HCP au sein de trois projets de recherche à grande échelle sur le terrain, dont un également contaminé aux éléments traces. Deux projets ont été effectués dans un climat subarctique au 60° parallèle (Whitehorse, Yukon), en utilisant une approche novatrice de phytoremédiation assistée de champignons et compost municipal; nous qualifions cette technique intégrée d’approche par « microsystème écologique ». Comme le volume de sol affecte beaucoup l’efficacité des méthodes de bioremédiation, des volumes considérables de 0.15 m3 et 1 m3 ont été utilisés (au premier et deuxième site, respectivement), pour maximiser la pertinence des résultats lors de transfert d’échelles futures. Au premier site, l’efficacité des différentes composantes du microsystème a été évaluée en bacs dans quatre différentes combinaisons et comparée au traitement de base habituel (fertilisant) dans un sol contaminé par un déversement accidentel de diésel. La plante choisie était le saule Salix planifolia et le champignon Pleurotus ostreatus. Les résultats indiquent qu’après une saison de traitement, le microsystème était le traitement avec le taux d’élimination du diésel le plus rapide. Après trois saisons, les traitements contenant un ou plusieurs éléments du microsystème avaient des taux de contamination sous les normes pour des sols agricoles et étaient plus efficaces que le traitement au fertilisant ou que l’atténuation naturelle. Le deuxième site était une fosse à huiles usées située sur une pile de stériles miniers au cœur d’un ancien dépotoir. Le microsystème a été implanté dans des cellules au sol avec une doublure à l’épreuve du lessivât de contaminants. Les saules Salix alaxensis et Salix planifolia furent utilisés en combinaison avec le champignon Trametes versicolor. Cette approche, dans un sol hautement contaminé, a réussi à diminuer de façon considérable les hydrocarbures pétroliers (plus de 65 à 75 %). Le potentiel d’accumulation des métaux dans les tissus aériens des plantes a également été mesuré. Les deux espèces de saules ont démontré des taux d’accumulation d’éléments traces distincts et des stratégies racinaires différentes. Un champignon de la famille des Psathyrellaceae fut observé pour la première fois sur un site si hautement contaminé, puis est apparu de façon récurrente sur les cellules du microsystème pendant quatre ans. Les deux premiers sites répondent à un besoin de développer des méthodes de bioremédiation efficaces, passives et applicables en climat subarctique. Le troisième site de recherche porte sur l’utilisation de deux matières résiduelles fertilisantes (bois raméal fragmenté et drêche) et de fumier pour la dégradation de l’huile à moteur dans un climat continental humide à une latitude moyenne (Neuville, Québec). Des mésocosmes de 0.76 m3 avec aération contrôlée furent utilisés. L’utilisation de bois raméal fragmenté et de drêche de brassage à cette échelle, de même que l’acquisition des matières résiduelles dans un rayon très rapproché du centre de traitement afin d’explorer une approche d’économie circulaire dans un tel contexte, constituent les volets novateurs de cette étude. Les résultats démontrent que le fumier est plus efficace que le traitement habituel au fertilisant. La drêche de brassage et le bois raméal fragmenté sont utiles pour conserver l’humidité dans les sols (un paramètre de bioremédiation important). Cette étude, menée en collaboration avec un partenaire industriel, s’intègre dans la politique canadienne et québécoise de réductions des gaz à effets de serre et la philosophie de l’économie circulaire en valorisant des matières organiques résiduelles locales. Cette thèse a permis de démontrer qu’une combinaison de stratégies de bioremédiation avec des composantes locales est une méthode efficace dans un climat subarctique. Deux nouvelles espèces de saules (Salix planifolia et Salix alaxensis) ont été utilisées avec succès pour la bioremédiation d’hydrocarbures pétroliers et pour l’accumulation de certains éléments traces. Lors d’une collaboration avec un partenaire industriel, il a été possible de démontrer l’applicabilité de certains concepts d’économie circulaire et d’approche écosystémique en bioremédiation.
Petroleum hydrocarbons are shipped and used in virtually all parts of the world and have become one of the most common and widespread contaminants in soils. Trace elements are sometimes associated with them, and they can increase the toxicity of a site, complicate remediation, and increase the costs of traditional treatments. In northern areas where spills occur at multiple sites, the clean-up time and cost of traditional remediation methods can be significantly higher than in temperate regions. Alternative research aimed at faster and cheaper remediation adapted to subarctic climates is needed and the use of native plants and fungi integrated into the local ecosystem are promising approaches. Concurrently, governments in multiple countries aim to reduce greenhouse gas emissions, namely through the reduction of putrescible waste destined for landfills. By using locally-sourced residual fertilizing materials for decontamination processes, an opportunity arises to valorize these materials while restoring soils. This doctoral research aims to develop locally-adapted bioremediation methods, with indigenous plant and fungal inputs, to treat petroleum hydrocarbon contaminated soils in three large-scale field research projects, including one also contaminated with trace elements. Two projects were carried out in a subarctic climate at the 60 ° parallel (Whitehorse, Yukon), using an innovative approach of phytoremediation assisted by mushrooms and municipal compost; we call this integrated technique the "ecological microsystem" approach. Because soil volume has significant impacts on the efficiency of bioremediation methods, considerable volumes of 0.15 m3 and 1 m3 were used (at the first and second sites, respectively) to maximize the relevance of results in the event of a scale-up operation. At the first site, the effectiveness of the various components of the microsystem were evaluated in four different combinations, as well as compared to the usual basic treatment (fertilizer) in soil contaminated by an accidental diesel spill. The plant species chosen was Salix planifolia and Pleurotus ostreatus was selected for the fungus. Results indicate that after one treatment season, the microsystem was the treatment with the fastest diesel removal rates. After three seasons, treatments containing one or more elements of the microsystem were below standards for agricultural soils and were more effective than fertilizer treatment or natural attenuation. The second northern site was a waste oil pit located on top of a mine waste rock pile, at the heart of an old landfill. The microsystem was implanted into ground-level cells with a contaminant-proof leachate liner. The plant species Salix alaxensis and Salix planifolia were used in combination with the fungus Trametes versicolor. This approach in a highly contaminated soil was able to significantly reduce petroleum hydrocarbons (65 to 75%). The potential for metal accumulation in aerial plant tissues was also measured. Both willow species demonstrated distinct trace element accumulation patterns and different rooting strategies. A fungus of the Psathyrellaceae family was observed for the first time at a site so highly contaminated and was recurrent on the cells of the microsystem for 4 years. The first two sites contribute to the development of efficient and passive bioremediation methods applicable in subarctic climates. The third research site focused on the use of two residual fertilizing materials (fragmented rameal wood and brewer’s spent grain) and manure for the degradation of motor oil in a humid continental climate at a medium latitude (Neuville, Quebec). Mesocosms of 0.76 m3 with controlled aeration were used. Innovative aspects of this project include the use of rameal wood and spent grain at this scale, as well as the acquisition of residual materials in a very close radius of the treatment center to explore how a circular economy approach could apply in such a context. Results indicate that the addition of manure is more effective than the usual fertilizer treatment alone. Brewer’s spent grain and fragmented rameal wood were useful for maintaining soil moisture (an important bioremediation parameter) but did not increase degradation. This study, conducted in close collaboration with an industrial partner, falls under the objectives set by Canadian and Quebec policy on greenhouse gas reductions and circular economy approaches by working on the valorization of local residual organic matter. This thesis has demonstrated that combining strategies with local biological components is an effective bioremediation method in a subarctic climate. Two new willow species (Salix planifolia and Salix alaxensis) have been successfully used for the bioremediation of petroleum hydrocarbons and for the accumulation of certain trace elements. In collaboration with an industrial partner, it has been possible to demonstrate the applicability of certain circular economy concepts and the ecosystemic approach to bioremediation.

Im Bereich der industriellen Metallurgie und Kristallzüchtung treten bei zahlreichen Anwendungen, wo magnetische Wechselfelder zur induktiven Beeinflussung von leitfähigen Werkstoffen eingesetzt werden, auch Strömungen mit freier Oberfläche auf. Das Anwendungsspektrum reicht dabei vom einfachen Aufschmelzen eines Metalls in einem offenen Tiegel bis hin zur vollständigen Levitation. Auch der sogenannte RGS-Prozess, ein substratbasiertes Kristallisationsverfahren zur Herstellung siliziumbasierter Dünnschichtmaterialien, ist dafür ein Beispiel. Um bei solchen Prozessen die Interaktion von Magnetfeld und Strömung zu untersuchen, ist die numerische Simulationen ein wertvolles Hilfsmittel. Für beliebige dreidimensionale Probleme werden entsprechende Berechnungen bisher durch eine externe Kopplung kommerzieller Programme realisiert, die für Magnetfeld und Strömung jeweils unterschiedliche numerische Techniken nutzen. Diese Vorgehensweise ist jedoch im Allgemeinen mit unnötigem Rechenaufwand verbunden. In dieser Arbeit wird ein neu entwickelter Methodenapparat auf Basis der FVM vorgestellt, mit welchem sich diese Art von Berechnungen effizient durchführen lassen. Mit der Implementierung dieser Methoden in foam-extend, einer erweiterten Version der quelloffenen Software OpenFOAM, ist daraus ein leistungsfähiges Werkzeug in Form einer freien Simulationsplattform entstanden, welches sich durch einen modularen Aufbau leicht erweitern lässt. Mit dieser Plattform wurden in foam-extend auch erstmalig dreidimensionale Induktionsprozesse im Frequenzraum gelöst.