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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Impact des hydrocarbures aromatiques polycycliques sur le métabolisme lipidique et le transport du phosphore chez le champignon mycorhizien à arbuscules Rhizophagus irregularis / Polycyclic aromatic hydrocarbons impact on lipid metabolism and phosphorus transport in the arbuscular mycorrhizal fungus Rhizophagus irregularis

Calonne, Maryline 04 December 2012 (has links)
Les hydrocarbures aromatiques polycyliques (HAPs) figurent parmi les polluants organiques persistants majeurs des sols pollués et présentent une toxicité avérée vis-à-vis de l'homme et des écosystèmes. Parmi les méthodes de remédiation des sols pollués par les HAPs, la phytoremédiation assistée par les champignons mycorhiziens à arbuscules (CMA), pourrait représenter une alternative innovante, écologique et économique. L'utilisation des mycorhizes comme outil de phytoremédiation des sols pollués présente plusieurs avantages dont une meilleure tolérance à la toxicité des HAPs, une meilleure nutrition hydrique et minérale ainsi qu'une meilleure dissipation des HAPs. De rares études ont décrit l'impact des HAPs sur le développement des CMA en lien avec une péroxydation lipidique et une perturbation des teneurs en lipides du CMA, mais ni les cibles d'action de ces polluants au niveau du métabolisme lipidique, ni le rôle de ces modifications dans sa tolérance aux HAPs et dans leur dissipation n'ont été étudiés. C'est pourquoi, le premier objectif de ce travail vise tout d'abord à comprendre l'impact des HAPs sur le métabolisme lipidique. Le radiomarquage par l'acétate [1-¹⁴C] a permis de montrer une perturbation de la biosynthèse des lipides membranaires du CMA extra-racinaire. D'autre part, nos résultats montrent que les HAPs affectent la nutrition phosphatée. Par ailleurs, la capacité des mycorhizes à dégrader et à bioaccumuler le benzo[a]pyrène est démontrée. Enfin, l'implication du métabolisme des lipides de réserve (les triacylglycérols) du mycélium extra-racinaire dans la régénération des membranes altérées, la lutte contre le stress oxydant induit par les HAPs et dans leur métabolisation/bioaccumulation est discutée. / Polycyclic aromatic hydrocarbons (PAHs) are among the major persistent organic pollutant frequently found in the polluted soils and are harmful for human health and its environment. To clean-up the PAHs polluted soils, phytoremediation assisted by arbuscular mycorrhizal fungi (AMF) could represent an innovative, ecological and cost-effective alternative. The use of mycorrhizas, as phytoremediation tool, has several advantages including increased tolerance to the pollutant toxicity, improved water and mineral nutrition as well as a better pollutant dissipation. Few studies have described the impact of PAHs on the AMF development related with lipid peroxidation and total lipid content disturbance. However, so far neither the target action of these pollutants on the metabolism, nor the role of these lipid changes in PAH tolerance and in their dissipation have been studied. Therefore, the present work aims firstly to improve our understanding of the PAHs impact on the CMA lipid metabolism. Thanks to radiolabeling experiments with [1-¹⁴C] acetate, our results showed a disruption of the membrane lipid biosynthesis pathways in the AMF extraradical mycelium, grown in the presence of PAHs. Secondly, it was highlighted that the PAHs affectef the phosphate nutrition. Finally, the mycorrhizas abilities to degrade and to bioaccumulate the benzo[a]pyrene, were pointed out. The involvement of extraradical mycelium storage lipid (triacyglycerols) metabolism in the membrane regeneration, the fight against the PAH induced-oxidative stress and the PAH metabolism/bioaccumulation is discussed.
122

Aplicação de aeração intermitente para a degradação de corante azo por consórcio microbiano obtido de florestas tropicais / Intermittent aeration strategy for enhanced azo dye degradation by microbial consortium obtained from tropical forests

Oliveira, Jean Maikon Santos 01 March 2019 (has links)
As soluções convencionais de tratamento biológico de corantes azo são baseadas em processos anaeróbio-aeróbios ocorrendo em unidades distintas. Este estudo avaliou o uso da aeração intermitente para a descoloração do Direct Black 22 (DB22) e biodegradação simultânea de subprodutos tóxicos no mesmo compartimento reacional. Os microrganismos utilizados foram obtidos de florestas tropicais e previamente adaptados a concentrações crescentes de DB22 (10-32,5 mg.L-1) em meio de cultivo. Os efeitos da concentração inicial de glicose (1 – 2 – 3 g.L-1) e aeração intermitente (0 – 4 – 8 h.d-1) sobre a descoloração, constante de descoloração e remoção de demanda química de oxigênio (DQO) foram investigados por planejamento fatorial e análise de superfície de resposta. Os testes foram conduzidos com água residuária (AR) que simulava a composição dos efluentes de lavanderias têxteis do agreste pernambucano. Os resultados demonstraram que a descoloração no longo prazo não foi inibida para ciclos de aeração de até 4 h.d-1, embora menores velocidades de remoção de cor tenham sido obtidas nestas condições. Os efeitos negativos da aeração foram significativamente reduzidos pelo aumento da concentração de glicose na AR. Ademais, a remoção de DQO foi potencializada com o aumento da frequência de aeração. Após descoloração do DB22 nos ensaios não aerados, verificou-se a formação de picos de absorbância relacionados à presença de aminas aromáticas ou outros intermediários da descoloração redutiva; o que não ocorreu nos experimentos aerados. Estes fatores resultaram em menor toxicidade à Daphnia magna em experimento modelo com nível intermediário de aeração. O sequenciamento do gene 16S rRNA na plataforma Illumina HiSeq revelou a presença de gêneros de bactérias conhecidos por produzirem enzimas envolvidas na biodegradação do azo. Observou-se, ainda, uma correlação positiva entre diversidade microbiana e eficiência de descoloração. Os resultados sugerem que a estratégia de aeração intermitente, corretamente implementada, pode melhorar a performance do tratamento biológico de efluentes têxteis que contém azo-corantes. / Conventional technologies for biological treatment of azo dyes are based on anaerobic-aerobic processes taking place into distinct units. This study evaluated the use of intermittent aeration strategy for decolorization of the Direct Black 22 (DB22) and simultaneous biodegradation of metabolites. Microorganisms were obtained from tropical forests and previously acclimated to increasing concentrations of DB22 (10-32.5 mg.L-1) in growth medium. Effects of initial glucose concentration (1 – 2 – 3 g.L-1) and intermittent aeration (0 – 4 – 8 cycles.d-1) on response variables decolorization, decolorization rate, and removal of chemical oxygen demand (COD) were investigated using factorial design and response surface analysis. Tests were conducted using a wastewater that simulated the composition of textile laundry effluents from a region with harsh climate in the state of Pernambuco, known as agreste pernambucano. Results showed long-term decolorization was not impaired for up to 4 cycles.d-1 of aeration, although a decrease in color removal velocities was observed in these experiments. Negative impacts of aeration were significantly reduced by increasing initial glucose concentration. Moreover, COD removal was enhanced with increased aerations levels. After DB22 degradation in non-aerated batches, the formation of absorbance peaks associated with aromatic amines and other byproducts of reductive decolorization was observed; which did not occur in the aerated experiments. These resulted in lower toxicity to Daphnia magna in model experiment using intermediate level of aeration. 16S rRNA gene sequencing on the Illumina HiSeq platform revealed the presence of several bacteria known to produce enzymes involved in azo compounds degradation. Furthermore, a positive correlation between microbial diversity and decolorization efficiency was observed. Results suggest intermittent aeration strategy can enhance biological treatment of textile effluents containing azo dyes when correctly implemented.
123

Devenir photochimique de la carbamazépine et sous-produits dans des eaux naturelles et écotoxicologie à doses environnementales / Photochemical fate of carbamazepine and transformation products in waterbodies and ecotoxicology at low doses

Desbiolles, Fanny 29 June 2018 (has links)
La carbamazépine (CBZ) est un antiépileptique largement consommé, peu dégradé dans les stations de traitement des eaux usées et donc rejeté dans les eaux de surface. Cette thèse vise à étudier le devenir de CBZ et de deux métabolites, l'oxcarbazépine (OxCBZ) et l'acide 9-carboxylique acridine (9-CAA), sous irradiation par la lumière solaire dans des eaux naturelles douces et salées. Les suivis cinétiques ont permis de mettre en évidence des comportements différents en fonction des composés mais aussi des types d’eaux et impliquant des mécanismes de phototransformation directe et induite mais aussi des réactions d’atténuation naturelle. Pour approfondir ces résultats, la spectrophotométrie d’absorption résolue en temps et l’utilisation d’une sonde chimique ont souligné la formation d’espèces réactives (radicaux hydroxyles, carbonates et halogénés) et des réactions de compétition ont permis de mesurer leur réactivité avec les composés étudiés.La formation de dérivés issus de processus d’hydroxylation, d’oxydation, de perte de la fonction latérale, d’ouverture et/ou contraction de cycle aromatique (etc.) et de sous-produits halogénés dans les eaux salées ont été identifiés lors de la photodégradation de CBZ, OxCBZ et 9-CAA. Enfin, l’écotoxicité aiguë et chronique de CBZ, OxCBZ et 9-CAA a été évaluée individuellement et en mélange à dose environnementales sur 3 espèces vivantes de différents niveaux trophiques en mesurant les paramètres suivants : luminescence sur la bactérie Vibrio fischeri, phytométabolites sur la lentille d'eau Lemna minor et altération aux niveaux population, cellulaire et moléculaire sur le cnidaire Hydra circumcincta. / Carbamazepine (CBZ) is a widely consumed anti-epileptic pharmaceutical drug, inefficiently removed in activated sludge secondary treatment process. Consequently, it is almost completely rejected in its original form into surface waters. Hence, this thesis aimed to study the fate of CBZ and two of its known bio-metabolites, i.e. oxcarbazepine (OxCBZ) and 9-carboxylic acridine acid (9-CAA), under solar light irradiation in fresh and salty waters. Kinetic monitoring revealed different behaviours both compounds and water types dependent implying photolysis, induced photodegradation but also natural attenuation reactions. To deeper understand these results, laser flash photolysis experiments and the use of a chemical probe highlighted the formation of reactive species (hydroxyl, carbonate and halogenated radicals). By implementing competition reactions, the rate constants of each compound with each chemical radical species were determined.The formation of derivatives from hydroxylation, oxidation, ring contraction, loss of side function, aromatic ring opening (etc.) and also halogenated by-products in salty waters were identified throughout CBZ, OxCBZ and 9-CAA phototransformations.Finally, acute and chronic ecotoxicity of CBZ, OxCBZ and 9-CAA individually and in mixture at environmental concentration levels were investigated on 3 living species from different trophic levels. The following endpoints were monitored: luminescence on the bacteria Vibrio fischeri, growth and development and phytometabolites on the duckweed Lemna minor and alterations at the population, cellular and molecular levels on the cnidarian Hydra circumcincta.
124

Avaliação toxicogenética e ecotoxicológica de corantes têxteis / Toxicogenetic and ecotoxicological assessment of textile dyes

Oliveira, Gisele Augusto Rodrigues de 12 June 2013 (has links)
O tingimento de tecidos começou há milhares de anos e a disponibilidade comercial de corantes é enorme e crescente. A indústria têxtil brasileira desempenha um papel de inquestionável importância, destacando-se entre as principais atividades econômicas do país. O processo de tingimento é um dos fatores fundamentais no sucesso comercial dos produtos têxteis, uma vez que o consumidor exige cores resistentes à exposição ao calor, à luz, à transpiração e às lavagens. Segundo a literatura, condições de transpiração intensa contribuem para uma alta taxa de migração e subseqüente penetração de corantes têxteis para a pele humana. Além disso, 2 a 50% desses compostos permanecem no banho de tingimento e são descartados nos efluentes industriais, contaminando o ambiente e colocando em risco a saúde humana, uma vez que os métodos convencionais de tratamento de efluentes são ineficientes na remoção da coloração e da mutagenicidade de alguns corantes. Dentro deste contexto, este trabalho teve como objetivo avaliar os efeitos toxicogenéticos do corante Direct Black (DB38) original e após extração por lixiviação com suor sintético, utilizando o teste do cometa com fibroblastos e queratinócitos de pele humana, o teste Anexina V com fibroblastos e o ensaio de mutagenicidade com Salmonella typhimurium. Adicionalmente, foi investigada a ecotoxicidade dos corantes têxteis Direct Black 38 e Reactive Blue 15 (RB15) originais por meio de ensaios com sementes, dapnhias, minhocas e zebrafish realizados na UTOX, em Barcelona. O corante DB38 original e lixiviado não induziram genotoxicidade em fibroblastos e queratinócitos de pele humana. O corante DB38 original foi mutagênico para as linhagens TA98 e TA100 de S. typhimurium na presença de S9. Entretanto, o corante lixiviado não induziu mutagenicidade para essas linhagens testadas, considerando que a maior taxa de migração do corante para a solução de suor foi de ~1% nas seguintes condições: tingimento sem ensaboamento, pH 8,0 e 8 horas de incubação à 42°C. O corante original é citotóxico para fibroblastos após 48 horas de exposição. No entanto, essa citotoxicidade não foi mais observada após a lixiviação no suor. Os corantes DB38 e RB15 originais não foram tóxicos para as sementes de pepino, alface e tomate, e nem para as minhocas Eisenia foetida. Ambos os corantes foram fracamente tóxicos para Daphnia magna, porém o RB15 apresenta maior potencial tóxico em relação ao DB38. Os corantes DB38 e RB15 induziram malformações em larvas de zebrafish Danio rerio, caracterizadas por falha na inflação da bexiga natatória e alteração na cauda. Portanto, nossos resultados mostram a importância de se fazer não só a análise individual de corantes têxteis, mas também dos tecidos que os contêm. Além da necessidade de se desenvolver técnicas de tingimento mais seguras em relação à solidez da cor sob condições úmidas e as perdas de corante para o ambiente durante a etapa de fixação, indicando maior atenção ao estudo de efeitos sub-letais na avaliação do impacto desses compostos no ecossistema aquático. / The fabrics dyeing began thousands of years ago and the commercial availability of dyes is increasingly. The Brazilian textile industry plays a role of high importance, highlighting among the main economic activities in the country. The dyeing process is one of the key factors in the commercial success of textile products, since consumers are demanding colors more resistant to heat, light exposure, perspiration and washing. According to the literature, conditions of intense perspiration contribute to the migration and subsequent penetration of textile dyes to human skin. Furthermore, 2 to 50% of the initial dye load is present in the dye bath effluent and these compounds are discharged in industrial effluents, contaminating the environment and endangering human health, since the wastewater treatment systems are ineffective in removing the color and mutagenicity of some dyes. In this context, this study aimed to evaluate the toxicogenetic effects of the Direct Black 38 (DB38) dye original and extracted by leaching with artificial sweat using Comet assay with fibroblasts and keratinocytes from human skin, Anexin V assay with fibroblasts and Salmonella mutagenicity test. Additionally, we investigated the ecotoxicity of textile dye Direct Black 38 and Reactive Blue 15 (RB15) using assays with seeds, dapnhias, worms and zebrafish performed in UTOX in Barcelona. The original and leached DB38 dye did not induce genotoxicity in fibroblasts and keratinocytes from human skin. The original DB38 was mutagenic for TA98 and TA100 of S. typhimurium with S9. However, the solution with the leached dye did not induce mutagenicity for these tested strains, since the highest migration rate of the dye to the solution of artificial sweat was ~ 1% in the following conditions: type of dyeing without rinsing, pH 8.0 and 8-hour incubation at 42°C. The original dye was cytotoxic for fibroblasts after 48 hours of exposure. However, this cytotoxicity was no longer observed after leaching in sweat. The original DB38 and RB15 dyes showed no toxicity for cucumber, lettuce and tomato seeds and for earthworms Eisenia foetida. Both dyes were weakly toxic for Daphnia magna, but the RB15 has a higher toxic potential compared to DB38. The dyes DB38 and RB15 induced malformations in larvae of zebrafish Danio rerio by failure of the swim bladder inflation and changes in the tail. Therefore, our results show the importance of making the individual analysis of textile dyes, but also of fabrics containing them. Furthermore, it is necessary to develop safer techniques of dyeing in relation to the color fastness under humid conditions and the loss of dyes into the environment during the fixation step, indicating more attention to the study of sub-lethal effects in the evaluation of the impact of these compounds in the aquatic ecosystem.
125

Jämförande LCA av engångssängkläder och tvättbara sängkläder i sjukvården / A comparative LCA of disposable and washable beddings used in healthcare

Strömner, Fredrik January 2014 (has links)
Inom sjukvården används – precis som överallt där människor sover – sängkläder av hygienskäl. Problem med smittspridningar av typen multiresistenta bakterier (MRSA) och spridning av andra sjukdomar har drivit företag som Cellcomb i Karlstad AB till att utveckla engångssängkläder för att förhindra detta. Engångssängkläderna är skyddade av en biofilm som ska ge ökat skydd mot bakterier och fungerar som en barriär så att inte vätska tränger igenom. Problemet är att det inte finns mycket till underlag för hur engångssängkläderna står sig mot vanliga sängkläder ur miljösynpunkt. I dagsläget använder sjukhus traditionella sängkläder till sina patienter och sedan transporteras dessa till tvätteri och tvättas. Att tvätta och torka sängkläder är energikrävande och ett alternativ till detta skulle kunna vara att använda engångssängkläder. En förenklad LCA gjordes för att ta reda på om sängkläder tillverkade av bomull och polyester eller engångssängkläder tillverkade av polypropylen alternativt viskosmaterialet Tencel är det mest miljövänliga. För att ta reda på det gjordes studiebesök och data samlades in genom en litteraturstudie och från företag. Resultaten visade att i ett grundfall med Centralsjukhuset i Karlstad var energianvändningen för de tvättbara sängkläderna lägre än Tencel och försumbart lägre än polypropylen. Flera fall med känslighetsanalyser gjordes för att undersöka hur indata påverkade resultaten. Fallen visade att det kan variera vilket av alternativen som blir mest gynnsamt, framför allt när det gäller vilken typ av energi tvätteriet använder. Engångssängkläderna av Tencel visade sig vara bäst när det gällde andel förnybar energi följt av de tvättbara sängkläderna och sist polypropylen. Ur ett ekotoxicitets- och vattenanvändningsperspektiv blev båda engångssängkläderna mer gynnsamma än de tvättbara sängkläderna. Två slutsatser kan dras utifrån den här studien: de tre alternativen är likvärdiga energimässigt utifrån energianvändning, andel förnybar energi och de fallstudier som gjorts, men att engångssängkläderna står sig bättre när det gäller ekotoxicitet samt vattenanvändning. Den andra slutsatsen är att resultaten är fallberoende. En utökad studie skulle kunna göras med fler viktiga miljöparametrar och fler känslighetsanalyser. / In healthcare – as in any other place where people sleep – beddings are used for hygiene reasons. Problems with spreading of bacteria diseases such as multi resistant bacteria (MRSA) and various other diseases have pushed companies like Cellcomb i Karlstad AB to develop disposable beddings in order to prevent this. These disposable beddings are protected with a biofilm which serves as a barrier, preventing liquids to pass through. The problem is that there is not much information about how these beddings perform from an environmental perspective. At present, hospitals are using traditional beddings for their patients and are then transported to laundries for washing. This is an energy intensive process and as an alternative, disposable beddings could be used. A simplified LCA was used to find out if beddings made out of cotton and polyester or disposable beddings made out of polypropylene or a viscose material called Tencel was the most favourable from an environmental perspective. To achieve this, various study visits were performed along with a literature study and data collection from companies. The results showed that for a basic case performed with Centralsjukhuset i Karlstad the washable beddings used less energy than Tencel and negligibly less energy than polypropylene. Several case studies were performed in order to examine how different data could alter the results. The case studies showed that which of the alternatives became the most favourable varied depending on the case, especially regarding which kind of energy was being used in the laundry. The disposable beddings made out of Tencel proved to be the best alternative regarding the use of renewable energy, followed by the washable beddings and last polypropylene. From a perspective of eco toxicity and water use both of the disposable beddings turned out more favourable. Two conclusions could be drawn from this study: the alternatives are equally favourable regarding energy use, renewable energy use and the case studies that were performed, but the disposable beddings are more preferable concerning eco toxicity and water use. The second conclusion is that the results depend on which case is studied. An expanded study could be performed using more environmental parameters.
126

The life cycle assessment of the Milazzo peninsula (north-eastern Sicily, Italy) : geochimical impact assessment of water and soils

Mey, Morgane 23 April 2013 (has links) (PDF)
The Milazzo peninsula, North-Eastern Sicily, Italy, is the implantation site of potentially polluting anthropogenic activities. Among them, a refinery and a thermoelectric plant. An epidemiological study has shown a decrease of human health quality in the area, but there was no further research as to the reasons of this observation. The aim of this work is to better understand how the Milazzo peninsula's anthropogenic emissions impact the local human health and ecosystems. The Life Cycle Assessment calculating approach was chosen in order to study the consequences of the emissions resulting from the following local anthropogenic activities: the thermoelectric plant, the refinery, the road traffic, the illegal combustion of domestic waste. The Impact 2002+ and the ReCiPe 2008 global-scale models were chosen, as well as a site-specific approach. In order to conduct this site-specific calculation, Milazzo soils and seawater samples were gathered and the specific local parameters were deduced from their analyses. The global-scale results pointed out the waste combustion emissions and the thermoelectric plant as the main causes of the human health quality decrease, while the thermoelectric plant was pointed out as the anthropogenic activity causing the most environmental damages. The site-specific study applied to the soil and seawater ecotoxicity confirmed the important role of the thermoelectric plant's emissions in the damages upon the environment, especially the seawater. Moreover, the site-specific study also corrected the soil ecotoxic impact scores, showing the importance of both thermoelectric plant and illegal waste combustion contributions to the damaging of the environment. As a conclusion, LCA study as a whole enlightens and explains the previous observations of human health and ecosystem damages in the site of study while the site-specific study proved relevant in the peculiar area of Milazzo.
127

Löslighet och transport av sällsynta jordartsmetaller i Källfallsfältets gruvsandsmagasin / Solubility and transport of rare earth elements in the mine tailings of Källfallsfältet

de Campos Pereira, Hugo January 2014 (has links)
Löslighet och transport av sällsynta jordartsmetaller i Källfallsfältets gruvsandsmagasin Hugo de Campos Pereira Syftet med detta arbete har varit att kartlägga vilka mekanismer som styr lösligheten av sällsynta jordartsmetaller (eng. rare earth elements, REE) i sulfidhaltig anrikningssand vid den föredetta gruvan Källfallsfältet i Västmanland. För syftet har markvatten- och grundvattenprovtagning utförts, tillsammans med laktester och geokemisk modellering med Visual MINTEQ ver. 3.0. Resultaten visade att sulfidvittring är den främsta processen som styr pH i anrikningssanden, och därmed också indirekt REEs löslighet. Däremot är sulfidvittring ingen källa till REE i sig då ämnena inte föreligger sulfidbundna, något som oxiderat tillgänglighetstest NT ENVIR 006 visade. Istället går REE ut i lösning i anrikningssanden genom vittring av lättvittrade silikatmineral. Vanligtvis betraktas metall bunden i silikatform inte som geokemiskt aktiv. Jämförelser mellan laktester med olika jämviktstid visade att en kinetisk (tidsberoende) faktor föreligger, kopplad till nämnda silikatvittring, som påverkar pH och således också metallöslighet vid laktester på anrikningssanden. Vid jämförelse mellan laktester och halter i anrikningssandens mark- och grundvatten bör denna därmed vägas in. Det pH-statiska laktestet SIS-CEN/TS 14997 visade begränsad möjlighet att undersöka kinetik med anledning av att det utförs under förhållandevis kort tid, 48 timmar. REE- och Cu-halter vid syratitrering (de behandlingar med lägst syratillsatser) och enstegslakning (SIS-CEN ISO/TS 21268-2:2010) visade god, respektive förhållandevis god, överensstämmelse med uppmätta markvattenhalter. Detta visade att syratitrering och enstegslakning är laktest som är tillämpbara, respektive förhållandevis väl tillämpbara, för att uppskatta markvattenhalter i anrikningssanden. Specieringsmodellering med Visual MINTEQ ver. 3.0 visade att pH och DOC är de viktigaste parametrarna som styr REEs speciering i anrikningssandens mark-, grund och ytvatten. Samtliga REE bildar starka komplex med löst organiskt material, men koncentrationerna av DOC var generellt sett låga. I sura sulfatrika mark-, grund och ytvatten domineras specieringen av lösta sulfatkomplex, huvudsakligen (REE)SO4+, följt av fria hydratiserade joner som näst vanligaste förekomstform. Dessa resultat överensstämmer väl med tidigare modelleringsstudier av REEs speciering i sura sulfatrika vatten resulterande från gruvavfall. Med bakgrund av detta och av att REEs ekotoxicitet verkar överensstämma med den fria jon-modellen (eng. free ion model) förväntas REE uppvisa högre toxicitet vid låga pH-värden. / Solubility and transport of rare earth elements in the mine tailings of Källfallsfältet Hugo de Campos Pereira The mechanisms which govern the solubility of rare earth elements (REEs) in sulfide-containing tailings at the former mine site of Källfallsfältet (Västmanland, Sweden) were studied by the means of soil water and ground water sampling, leaching tests and geochemical modeling using Visual MINTEQ ver. 3.0. The results showed that weathering of sulfides is the primary process governing pH in the tailings, and thus also REE solubility. However, weathering of sulfides is no source for REE in itself since the elements are not bound in sulfides, which the oxidized availability test NT ENVIR 006 showed. Instead REE are released into solution by weathering of easily weathered silicates. Usually, metal bound in silicate form is not considered geochemically active. A kinetic (time dependent) factor, associated with the weathering of silicates, was found to affect pH and thus also metal solubility in leaching tests performed on the tailings. The standardized pH static leaching test (SIS-CEN/TS 14997) showed limitations in observing kinetic effects because of its relatively short equilibration time (48 h). Thus, in future studies with similar materials, leaching test kinetics should be taken into account when comparing leached concentrations with field measured concentrations. Acid titration and one step batch test (SIS-CEN ISO/TS 21268-2:2010) proved to be applicable and relatively well applicable to the tailings, respectively, in order to estimate soil solution concentrations. Speciation calculations using Visual MINTEQ ver. 3.0 showed that pH and DOC concentration are the most important factors which affect REE speciation in soil solution, ground water and surface water associated with the tailings. In acid sulfate rich solutions, low in DOC, speciation is dominated by sulfate complexes, mainly (REE)SO4+, followed by free dissolved ions as the second most common form. These results are in accordance with previous modeling studies of REE speciation in acid sulfate rich waters resulting from tailings. This, together with previous results showing that REE ecotoxicity seems to follow the free ion model, implies that the toxicity of the elements is expected to increase with decreasing pH value.
128

Toxicidade aguda sobre Daphnia similis decorrente de contaminação aquática recente e antiga por gasolina, etanol e suas misturas: simulações em escala de bancada. / Acute toxicity on Daphnia similis resulting from recent and aged aquatic contamination by gasoline, ethanol and their mixtures: simulations via lab scale.

Ludmila da Silva Cunha 11 February 2014 (has links)
A contaminação de ambientes aquáticos decorrente de acidentes com gasolina, álcool combustível e misturas binárias representa um risco crescente, tendo em vista as projeções do setor para os próximos 50 anos. O objetivo do presente estudo foi avaliar a toxicidade aguda da Gasolina C, Gasolina P e álcool combustível isoladamente e em misturas binárias, assim como de suas respectivas Frações Solúveis em Água (FSA) e Frações Dispersas em Água (FDA) sobre Daphnia similis. O estudo ainda incluiu a avaliação da toxicidade aguda remanescente na matriz água de uma contaminação antiga (intemperismo) com a Gasolina C. Paralelamente, foram conduzidos ensaios de toxicidade aguda com amostras ambientais (água subterrânea, superficial e elutriato a partir de sedimentos) de uma área alagada com histórico de contaminação antiga. O cultivo e os ensaios com D. similis foram de acordo com a NBR 12.713 (2009). Tanto a gasolina C quanto a P foram extremamente tóxicas para os organismos, apresentando valores médios de CE50% em 48 h de 0,00113% e 0,058% respectivamente. As diferenças entre os resultados obtidos com a Gasolina C e aqueles obtidos com suas frações FSA e FDA foram significativas (p < 0,05), sendo que não houve diferença significativa entre a toxicidade aguda da FSA e da FDA (p < 0,05). Os resultados obtidos com os ensaios com Gasolina P e FDA não apresentaram diferenças significativas entre si (p < 0,05), mas, foram significativamente diferentes daqueles obtidos com FSA (p < 0,05). Os resultados dos ensaios de toxicidade aguda com misturas binárias sugeriram efeito menos que aditivo (antagonismo). Os resultados da simulação de uma contaminação antiga demonstraram redução acentuada da toxicidade para D. similis ao longo de apenas 28 dias. Entretanto, com relação aos ensaios com as amostras ambientais da área com histórico de contaminação, apesar da ausência ou baixa toxicidade nas amostras de água superficial (sugerindo intemperismo), toxicidade alta foi observada em amostras de água subterrânea e no elutriato de sedimentos, sugerindo condições de adsorção aos sedimentos com alto teor de argila e/ou aprisionamento dos compostos em zona saturada. / The contamination of aquatic environments due to accidents with gasoline, alcohol fuel and their mixtures represents an increasing risk due to the projections made by the petroleum-based fuels industry for the next 50 years. The objective of the present study was to assess the acute toxicity of gasoline C, gasoline P, ethanol fuel separately and in mixtures, as well as their respective water-soluble fractions (WSF) and water-disperse fraction (WDF) on the bioindicator Daphnia similis. The study also included the assessment of the remaining acute toxicity in an aged gasoline C-contaminated water matrix with aging simulation for a 28-day period. Parallel to that, toxicity assays were conducted with environmental samples, including surface water, elutriate of sediments and groundwater from an aged contaminated area. The cultivation and the assays with D. similis were carried out according to NBR 12.713 (2009). Both gasoline C and P were highly toxic to D. similis, with CE50% in 48 h of 0.00113% e 0.058% respectively. The differences in acute toxicity between Gasoline C and its fractions WSF and WDF were significant (p <0.05). However, no significant difference was found between WSF and WDF fractions. Gasoline P and its WDF fraction had no significant differences (p < 0.05), but their toxicity were significant different from that one obtained with the FSA fraction (p < 0.05). Acute toxicity assays carried out with gasoline C and P mixed with ethanol fuel suggested effect less than additive (antagonism). The results obtained with the simulation of an aged contamination with Gasoline C showed sharp reduction in toxicity along 28 days. However, regarding the assays with environmental samples from an aged contamination, although absence or low toxicity was observed in the superficial water, severe toxicity was found in the sediments elutriate and in the groundwater, which was confirmed by the high concentrations of gasoline hydrocarbons in both matrixes. The results suggest that the contaminant was entrapped in the saturated zone and/or adsorbed to the sediments with high clay content.
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The life cycle assessment of the Milazzo peninsula (north-eastern Sicily, Italy) : geochimical impact assessment of water and soils / Analyse du cycle de vie des activités anthropiques de la péninsule de Milazzo (Nord-Est de la Sicile, Italie) : étude des impacts environnementaux sur les eaux et les sols

Mey, Morgane 23 April 2013 (has links)
La péninsule de Milazzo, au Nord-Est de la Sicile, en Italie, est le site d'implantation d'activités anthropiques potentiellement polluantes. Parmi elles, une raffinerie et une centrale thermoélectrique. Une étude épidémiologique a montré une diminution de la qualité de la santé humaine dans la zone, mais aucune recherche n'a approfondi les raisons de cette observation. Le but de ce travail est de mieux comprendre comment les émissions des activités anthropiques de la péninsule de Milazzo impactent la santé humaine à l'échelle locale ainsi que les écosystèmes. L'approche par l'Analyse du Cycle de Vie a été choisie afin d'étudier les conséquences des émissions provenant des activités anthropiques suivantes: la centrale thermoélectrique, la raffinerie, la circulation automobile, la combustion sauvage de déchets domestiques. Les modèles à l'échelle globale Impact2002+ et ReCiPe2008 furent choisis, ainsi qu'une approche site-spécifique. Afin de réaliser ces calculs à l'échelle site-spécifique, des échantillons de sols et d'eau marine provenant de Milazzo ont été rassemblés et les paramètres locaux spécifiques ont été déduits de leurs analyses. Les résultats à l'échelle globale on montré que la combustion des déchets ménagers et que la centrale thermoélectrique sont les activités anthropiques causant le plus de dommages environnementaux. L'étude site-spécifique appliquée à l'écotoxicité du sol et de l'eau de mer a confirmé l'importance du rôle des émissions de la centrale thermoélectrique dans les dommages sur l'environnement, en particulier sur l'eau de mer. De plus, l'étude site-spécifique a permis de corriger les scores d'impact du sol, montrant l'importance à la fois de la centrale thermoélectrique et de la combustion sauvage de déchets ménagers dans les dommages sur l'environnement. En conclusion, l'étude ACV a globalement montré et expliqué les observations précédentes concernant les dommages à la santé humaine et à l'environnement sur le site d'étude alors que l'étude site-spécifique s'est montrée pertinente pour la zone particulière de Milazzo. / The Milazzo peninsula, North-Eastern Sicily, Italy, is the implantation site of potentially polluting anthropogenic activities. Among them, a refinery and a thermoelectric plant. An epidemiological study has shown a decrease of human health quality in the area, but there was no further research as to the reasons of this observation. The aim of this work is to better understand how the Milazzo peninsula's anthropogenic emissions impact the local human health and ecosystems. The Life Cycle Assessment calculating approach was chosen in order to study the consequences of the emissions resulting from the following local anthropogenic activities: the thermoelectric plant, the refinery, the road traffic, the illegal combustion of domestic waste. The Impact 2002+ and the ReCiPe 2008 global-scale models were chosen, as well as a site-specific approach. In order to conduct this site-specific calculation, Milazzo soils and seawater samples were gathered and the specific local parameters were deduced from their analyses. The global-scale results pointed out the waste combustion emissions and the thermoelectric plant as the main causes of the human health quality decrease, while the thermoelectric plant was pointed out as the anthropogenic activity causing the most environmental damages. The site-specific study applied to the soil and seawater ecotoxicity confirmed the important role of the thermoelectric plant's emissions in the damages upon the environment, especially the seawater. Moreover, the site-specific study also corrected the soil ecotoxic impact scores, showing the importance of both thermoelectric plant and illegal waste combustion contributions to the damaging of the environment. As a conclusion, LCA study as a whole enlightens and explains the previous observations of human health and ecosystem damages in the site of study while the site-specific study proved relevant in the peculiar area of Milazzo.
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Toxicidade aguda sobre Daphnia similis decorrente de contaminação aquática recente e antiga por gasolina, etanol e suas misturas: simulações em escala de bancada. / Acute toxicity on Daphnia similis resulting from recent and aged aquatic contamination by gasoline, ethanol and their mixtures: simulations via lab scale.

Ludmila da Silva Cunha 11 February 2014 (has links)
A contaminação de ambientes aquáticos decorrente de acidentes com gasolina, álcool combustível e misturas binárias representa um risco crescente, tendo em vista as projeções do setor para os próximos 50 anos. O objetivo do presente estudo foi avaliar a toxicidade aguda da Gasolina C, Gasolina P e álcool combustível isoladamente e em misturas binárias, assim como de suas respectivas Frações Solúveis em Água (FSA) e Frações Dispersas em Água (FDA) sobre Daphnia similis. O estudo ainda incluiu a avaliação da toxicidade aguda remanescente na matriz água de uma contaminação antiga (intemperismo) com a Gasolina C. Paralelamente, foram conduzidos ensaios de toxicidade aguda com amostras ambientais (água subterrânea, superficial e elutriato a partir de sedimentos) de uma área alagada com histórico de contaminação antiga. O cultivo e os ensaios com D. similis foram de acordo com a NBR 12.713 (2009). Tanto a gasolina C quanto a P foram extremamente tóxicas para os organismos, apresentando valores médios de CE50% em 48 h de 0,00113% e 0,058% respectivamente. As diferenças entre os resultados obtidos com a Gasolina C e aqueles obtidos com suas frações FSA e FDA foram significativas (p < 0,05), sendo que não houve diferença significativa entre a toxicidade aguda da FSA e da FDA (p < 0,05). Os resultados obtidos com os ensaios com Gasolina P e FDA não apresentaram diferenças significativas entre si (p < 0,05), mas, foram significativamente diferentes daqueles obtidos com FSA (p < 0,05). Os resultados dos ensaios de toxicidade aguda com misturas binárias sugeriram efeito menos que aditivo (antagonismo). Os resultados da simulação de uma contaminação antiga demonstraram redução acentuada da toxicidade para D. similis ao longo de apenas 28 dias. Entretanto, com relação aos ensaios com as amostras ambientais da área com histórico de contaminação, apesar da ausência ou baixa toxicidade nas amostras de água superficial (sugerindo intemperismo), toxicidade alta foi observada em amostras de água subterrânea e no elutriato de sedimentos, sugerindo condições de adsorção aos sedimentos com alto teor de argila e/ou aprisionamento dos compostos em zona saturada. / The contamination of aquatic environments due to accidents with gasoline, alcohol fuel and their mixtures represents an increasing risk due to the projections made by the petroleum-based fuels industry for the next 50 years. The objective of the present study was to assess the acute toxicity of gasoline C, gasoline P, ethanol fuel separately and in mixtures, as well as their respective water-soluble fractions (WSF) and water-disperse fraction (WDF) on the bioindicator Daphnia similis. The study also included the assessment of the remaining acute toxicity in an aged gasoline C-contaminated water matrix with aging simulation for a 28-day period. Parallel to that, toxicity assays were conducted with environmental samples, including surface water, elutriate of sediments and groundwater from an aged contaminated area. The cultivation and the assays with D. similis were carried out according to NBR 12.713 (2009). Both gasoline C and P were highly toxic to D. similis, with CE50% in 48 h of 0.00113% e 0.058% respectively. The differences in acute toxicity between Gasoline C and its fractions WSF and WDF were significant (p <0.05). However, no significant difference was found between WSF and WDF fractions. Gasoline P and its WDF fraction had no significant differences (p < 0.05), but their toxicity were significant different from that one obtained with the FSA fraction (p < 0.05). Acute toxicity assays carried out with gasoline C and P mixed with ethanol fuel suggested effect less than additive (antagonism). The results obtained with the simulation of an aged contamination with Gasoline C showed sharp reduction in toxicity along 28 days. However, regarding the assays with environmental samples from an aged contamination, although absence or low toxicity was observed in the superficial water, severe toxicity was found in the sediments elutriate and in the groundwater, which was confirmed by the high concentrations of gasoline hydrocarbons in both matrixes. The results suggest that the contaminant was entrapped in the saturated zone and/or adsorbed to the sediments with high clay content.

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