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Degradação de HPAs e produção de enzimas ligninolíticas por fungos basidiomicetos derivados de esponjas marinhas / PAHs degradation and ligninolytic enzymes production by marine-sponge-derived basidiomycetes fungiMagrini, Mariana Juventina, 1985- 08 March 2012 (has links)
Orientadores: Lara Durães Sette, Rafaella Costa Bonugli Santos / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T03:33:56Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012 / Resumo: Hidrocarbonetos Policíclicos Aromáticos (HPAs) são poluentes ambientais oriundos de fontes naturais e antropogênicas, caracterizados por suas propriedades mutagênicas e carcinogênicas e persistência no ambiente. Fungos basidiomicetos de degradação branca têm sido extensivamente estudados devido à sua habilidade em degradar uma ampla variedade de compostos xenobióticos por meio do sistema ligninolítico, composto por enzimas de baixa especificidade ao substrato, como as Lacases, Manganês peroxidases (MnP) e Lignina peroxidases (LiP). Considerando que os estudos relacionados à degradação de poluentes por fungos marinhos ainda são escassos, o presente trabalho visou à avaliação da degradação dos HPAs pireno e BaP e da atividade ligninolítica de três basidiomicetos isolados de esponjas marinhas. Durante a etapa de seleção do fungo mais eficiente, os três basidiomicetos foram capazes de degradar os HPAs (0,02 e 0,04 mg mL-1 de BaP e pireno, respectivamente) após 7, 14 e 21 dias de incubação, apresentando atividade ligninolítica, sobretudo de Lacase, que possui uma ampla aplicação tecnológica. O fungo Marasmiellus sp. CBMAI 1062 degradou mais de 90% da quantidade inicial de ambos os HPAs após 7 dias de incubação. O crescimento dos basidiomicetos não foi influenciado pelos HPAs, com exceção do Marasmiellus sp. CBMAI 1062, que apresentou maior crescimento micelial em presença dos mesmos. A atividade ligninolítica não apresentou correlação com a degradação nem com o crescimento micelial, para todos os basidiomicetos estudados. Entretanto, os resultados sugerem que na presença dos HPAs pode ter havido indução da produção das enzimas Lacase e MnP. O fungo Marasmiellus sp. CBMAI 1062 foi selecionado para as etapas posteriores devido a sua produção enzimática, crescimento em presença dos HPAs e altas porcentagens de degradação. Após 7 dias de cultivo em presença dos HPAs em meio mineral, este fungo apresentou atividade das enzimas LiP, MnP e Lacase, elevadas taxas de degradação (79,9% de pireno e 95,2% de BaP) e aumento de biomassa, o que sugere o consumo, ao menos em parte, dos HPAs e/ou de seus produtos de degradação como fontes de carbono e energia. Nos experimentos de análise qualitativa de metabólitos formados, foram identificados quatro metabólitos: 1-hidroxipireno, pireno dihidrodiol e dihidroxipireno, derivados da degradação do pireno, e hidroxibenzo[a]pireno, derivado da degradação do BaP. Tais compostos sugerem a degradação dos HPAs via sistema enzimático CYP e epóxido hidrolases. Elevadas porcentagens de degradação foram obtidas em meio com 35 ppm (3,5%) de salinidade e pH 9,0. Contudo, nestas condições, a atividade ligninolítica de Lacase, LiP e MnP foi ausente. O aumento da concentração dos HPAs não diminuiu as taxas de degradação nem o crescimento micelial. De modo geral, as maiores porcentagens de degradação foram alcançadas sob elevada concentração de nutrientes. Através dos experimentos de degradação de BaP, foi possível propor um modelo matemático derivado da regressão múltipla do Delineamento Composto Central Rotacional (DCCR) para dois fatores. Os resultados do presente trabalho evidenciam o potencial do fungo Marasmiellus sp. CBMAI 1062 para remediação de ambientes salinos e/ou alcalinos bem como para a aplicação biotecnológica de suas enzimas ligninolíticas / Abstract: Polycyclic Aromatic Hydrocarbons (PAHs) are environmental pollutants from natural and anthropogenic sources, characterized by their mutagenic and carcinogenic properties and persistence in the environment. White-rot basidiomycetes have been extensively studied due to the ability to degrade a wide variety of xenobiotic compounds using their ligninolytic system, constituted by enzymes with low substrate specificity, such as Laccases, Manganese peroxidase (MnP) and Lignin peroxidases (LiP). Since the studies related to the degradation of pollutants by marine-derived fungi are scarce, the present study aimed to evaluate the degradation of PAHs pyrene and BaP and the ligninolytic activity of three basidiomycetes isolated from marine sponges. During the selection of the most efficient fungus, the three basidiomycetes were able to degrade PAHs (0.02 to 0.04 mg mL-1 BaP and pyrene, respectively) after 7, 14 and 21 days of incubation, presenting ligninolytic activity, especially Laccase, which has a wide technological application. The fungus Marasmiellus sp. CBMAI 1062 degraded more than 90% of the initial amount of both PAHs after 7 days of incubation. The growth of basidiomycetes was not affected by PAHs, except Marasmiellus sp. CBMAI 1062, which showed the highest mycelial growth in their presence. The ligninolytic activity was not correlated with the degradation nor with the mycelial growth, for all basidiomycetes studied. However, the results suggest that the presence of PAHs may have induced the Laccase and MnP production. Marasmiellus sp. CBMAI 1062 was selected for the subsequent assays due to its enzyme production, growth in the presence of PAHs and high degradation rates. After 7 days of growth in the presence of PAHs in mineral medium, this fungus showed activity of LiP, MnP and Laccase, high degradation rates (79.9% of pirene and 95.2% of BaP) and increased biomass, suggesting consumption, at least in part, of PAHs and/or their degradation products as carbon and energy sources. In qualitative analysis of the metabolites produced, four metabolites were identified: 1-hydroxypyrene, pyrene dihydrodiol and dihydroxypyrene, derived from the pyrene degradation, and hydroxybenzo[a]pyrene derived from BaP degradation. Such compounds suggest PAHs degradation via CYP enzyme system and epoxide hydrolases. High degradation percentages were obtained in medium with 35 ppt salinity (3.5%) and pH 9.0. However, under these conditions, the activity of ligninolytic Laccase, LiP and MnP was absent. Increasing the concentration of PAHs has not decreased rates of degradation or mycelial growth. In general, the major degradation percentages were achieved at higher nutrient concentration. Through the degradation of BaP assays, was possible to propose a mathematical model derived from multiple regression Central Composite Rotatable Design (CCRD) with two factors. The results of this study highlight the potential of fungus Marasmiellus sp. CBMAI 1062 for remediation of saline and/or alkali environments as well as for biotechnological application of their ligninolytic enzymes / Mestrado / Microbiologia / Mestre em Genética e Biologia Molecular
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Remediação de solo contaminado com hidrocarbonetos derivados de combustíveis utlizando lavagem oxidativa / Remediation of contaminated soil with hydrocarbons derived from fuels using oxidative washingMarques, Emanuel José Nascimento, 1983- 21 August 2018 (has links)
Orientador: Wilson de Figueiredo Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-21T12:42:03Z (GMT). No. of bitstreams: 1
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Previous issue date: 2012 / Resumo: Neste trabalho foi avaliado um processo de lavagem de solo utilizando solução oxidante, visando a remediação de áreas contaminadas com hidrocarbonetos provenientes combustíveis. O processo foi denominado de lavagem oxidativa e consistiu na mistura de H2O2 com um catalisador de Fenton modificado, chamado Fentox®. A lavagem oxidativa foi aplicada em solo contaminado artificialmente com óleo diesel em laboratório, a fim de avaliar as mudanças ocorridas no perfil de distribuição dos hidrocarbonetos remanescentes no solo tratado e verificar as condições experimentais que resultassem em máxima remoção destes contaminantes. Foi possível obter remoção de 90% para alcanos totais, 69% para hidrocarbonetos policíclicos aromáticos (HPA) totais, e 86% para hidrocarbonetos totais de petróleo (HTP). O aumento na proporção entre fase líquida e fase sólida resultou em maior eficiência na remoção dos contaminantes. A lavagem do solo utilizando o agente tensoativo dodecil benzeno sulfonato de sódio (DBSS) foi outro aspecto investigado em laboratório. Verificou-se que em solo com baixa concentração inicial de HPA o uso do tensoativo não favoreceu a solubilização dos contaminantes. Além disso, a adição de tensoativo durante a lavagem oxidativa do solo não contribuiu para melhorar o desempenho do processo de remediação. O processo de lavagem oxidativa juntamente com solução de tensoativo foi aplicado em solo contaminado com óleos combustíveis em uma área localizada na cidade de São Paulo, a fim de remover os hidrocarbonetos presentes no local. Foi obtida redução de aproximadamente 87% do parâmetro HPA total, sendo que a extensão da remoção individual dos HPA apresentou variações, principalmente em função da hidrofobicidade característica de cada composto. A lavagem oxidativa mostrou-se uma alternativa viável sob o ponto de vista técnico, considerando que os resultados obtidos em campo foram comparáveis àqueles obtidos em laboratório / Abstract: In this work a soil washing process using oxidizing solution was evaluated, aiming the remediation of contaminated areas with hydrocarbons derived from fuels. The selected process was called oxidative soil washing and consists in the use of H2O2 with a modified Fenton¿s catalyst, called Fentox®. The oxidative washing was applied first in a laboratory diesel oil contaminated soil in order to evaluate changes in the distribution profile of hydrocarbons remaining in the treated soil and to set the experimental conditions that resulted in maximum removal of these contaminants. It was possible to obtain removals of 90% for total alkanes, 69% for polycyclic aromatic hydrocarbons (PAH), and 86% for total petroleum hydrocarbons (TPH). The increase in the liquid-solid ratio resulted in increase of the contaminant removal. The oxidative soil washing using the surfactant sodium dodecyl benzene sulphonate (SDBS) was another aspect investigated in the laboratory. It was found that in soil having low initial PAH concentration, the use of surfactant did not increase the contaminants solubilization. Furthermore, the surfactant addition during the soil oxidative washing did not improve the performance of the remediation process. The oxidative soil washing in the presence of the surfactant solution was applied in a fuel contaminated soil to remove hydrocarbons. Results indicated removal around 87 % for total PAH, with different rates according to the hydrophobicity of each compound. Oxidative soil washing proved to be a feasible alternative under the technical point of view, considering that results obtained on site were comparable to the ones obtained under laboratory conditions / Mestrado / Quimica Analitica / Mestre em Química
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Compostage de déchets organiques avec des sols contaminés par des hydrocarbures aromatiques polycycliques (HAP) : impact de l'origine des déchets sur les rendements de biodégradation des HAP / Composting of organic waste for enhanced bioremediation of PAHs contaminated soilsLukic, Borislava 15 December 2016 (has links)
Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants organiques largement répandus dans l’environnement. Ils sont très fréquemment détectés dans les sols et sont principalement le produit d’une combustion incomplète de la matière organique. Etant toxiques et cancérigènes, de nombreuses études portant sur leur élimination des sols ont été massivement effectuées au cours des dernières années. Parmi tous les traitements disponibles pour traiter des sols contaminés par les HAP, les approches biologiques sont prometteuses car elles ont un impact limité, voire nul sur l’environnement. Cependant, leur efficacité est étroitement dépendante de nombreux facteurs difficiles à contrôler. L’objectif de cette thèse a été d’obtenir une connaissance plus précise concernant la dépollution biologique de sols contaminés par des HAP, en définissant à travers une série d‘expériences, les conditions les plus appropriées pour leur élimination principalement en termes de caractéristiques physiques et chimiques du sol, de la structure des HAP et leurs concentrations, la densité et la composition microbienne, le pH et l’humidité du sol et la disponibilité des nutriments. Les expériences réalisées dans cette thèse, sont basées sur le compostage de déchets organiques avec des sols contaminés par des HAP. L’ajout de matière organique vise à promouvoir la dégradation biologique simultanée des HAP et des déchets organiques frais en conditions contrôlées. Les résultats attendus de cette approche sont la dégradation des polluants en composés moins nocifs, en raison de la stimulation de l’activité des micro-organismes présents dans le sol ainsi que dans les déchets organiques apportés. Dans le but de comprendre l’influence des facteurs précédemment mentionnés, les expériences ont été menées sur un sol synthétique, artificiellement contaminé, ainsi que sur un sol contaminé provenant d’un site industriel identifié comme pollué par des HAP. Quatre types de déchets organiques frais ont été sélectionnés pour être ajoutés au sol artificiellement contaminé par des HAP. Les résultats ont montré que les boues activées étaient l’amendement organique le plus efficace par rapport au fumier de bufflonnes, aux déchets de cuisine et aux déchets organiques à base de légumes. Un taux d’élimination des HAP totaux supérieur à 60% a été atteint avec les boues activées. En outre, cette série d’expériences a prouvé que les conditions mésophiles étaient plus favorables que les conditions thermophiles, mais également que la teneur en azote, l’importance de la fraction soluble et les teneurs en protéines sont très importantes pour l’élimination des HAP. Sur la base de ces résultats, une série d’expériences a été menée sur un sol historiquement contaminé en apportant des quantités différentes de boues activées (ratio massique sol contaminé : boues activées variant de 1:2, 1:1 , 1:0,5 à 1:0). Contrairement aux résultats obtenus avec le sol artificiel, pour un sol naturellement contaminé, les amendements à base de boues activées n’ont pas stimulé l’élimination de HAP. Les meilleurs résultats ont été obtenu pour le sol non amendé par les boues activées (un rendement d’élimination des HAP totaux de 32% a été atteint en l’absence de boues activées, tandis qu'en présence d’un amendement à base de boues activées les meilleurs résultats ne dépassent pas 14% d’élimination des HAP totaux), cela prouve que la stimulation de micro-organismes pouvant dégrader les HAP est un facteur clé pour le succès du processus de dépollution biologique dans des conditions environnementales favorables / Polycyclic Aromatic Hydrocarbons (PAHs) are organic pollutants widely distributed in the environment and very frequently detected in soils as they are mainly produced from an incomplete combustion of organic matter at high temperature. They are toxic and even carcinogenic, therefore their removal from soils has been massively studied in the past years. Among all treatments suitable for treating soils contaminated by PAHs, biological ones are promising and challenging as they have a low or even no impact on the environment as well as their efficiency is tightly dependent on many factors not easy to control. The objective of this thesis has been to get more accurate knowledge on bioremediation of PAHs contaminated soils, by defining, through a series of experiments, the most suitable conditions for their biological remediation mainly in terms of physical and chemical soil characteristics, PAHs type and concentration, microbial density and composition, pH value, moisture content and availability of nutrients. The bioremediation experiments carried out in this thesis are based on landfarming as well as composting soil treatments and aimed at promoting the simultaneous biodegradation of PAHs and fresh organic wastes under controlled conditions. The expected result of this approach has been the conversion of organic pollutants into less harmful compounds, due to the activity of the microorganisms present in soil as well as in the organic waste added to soil. With the aim of deeply understanding the influence of the aforementioned factors on the bioremediation of PAHs contaminated soil, experiments were conducted on a synthetic soil, artificially contaminated, as well as on a real contaminated soil. In details, four different types of fresh organic waste were selected to be added to PAHs artificially contaminated synthetic soil and the results showed that centrifuged activated sewage sludge (SS) was the most effective organic amendment compared to buffalo manure (BM), food and kitchen waste (FKW) and fruit and vegetable waste (FVW). The removal efficiency of total PAHs reached with SS was actually a little higher than 60%. Furthermore, this set of experiments proved that mesophilic conditions were more performing than thermophilic conditions, as well as the content of nitrogen, soluble fraction and proteins played an important role in the PAHs removal. Based on the previous results, the next set of experiments was conducted on a real contaminated soil amended with different amounts of centrifuged activated SS (e.g. contaminated soil to SS mass ratios were 1:2, 1:1, 1:0.5 and 1:0 as wet weight basis). In contrast to results obtained with synthetic soil, in a real contaminated soil, SS amendment resulted in being not beneficial to PAHs removal. The best results were actually achieved where no SS was added (total PAHs removal efficiency of 32%, whereas with SS the best results showed a value of 14%), proving that the adaptation of microorganisms to PAHs is the key factor for the success of the bioremediation process coupled with setting favorable environmental conditions
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The effects of carbon deposition on catalyst deactivation in high temperature Fischer-Tropsch catalystsPatterson, Veronica A. January 2012 (has links)
In this work, carbonaceous deposits on spent HTFT catalysts were investigated. This research was required in order to better understand the observed loss in productivity observed in the industrial reactors, with the aim of improving the economy of the HTFT process. A host of complementary techniques were employed to systematically determine the composition of a typical catalyst recovered from a reactor. Spent HTFT catalysts are comprised of magnetite and a mixture of iron carbides as well as adsorbed hydrocarbon products (soft carbon) and hard carbon. Reaction initiates at the particle surface and along the promoter-rich grain boundaries toward the core of the grains. A partially reacted particle would therefore have a core-shell structure, with magnetite representing the unreacted region of the catalyst. The reacted region consists of a porous carbonaceous matrix with soft carbon and carbide crystallites nestled in this matrix. The hard carbonaceous species is a mixture of polymeric carbon and polycyclic aromatic hydrocarbons. The particle structure is linked to the sample preparation method and an alternative method yielding catalyst particle with uniformly distributed promoter elements could be beneficial. Investigating carbonaceous species is a complex process, and development of a fresh methodology would aid in the quest for insight into the nature of carbonaceous species in various systems. A new approach which entails a combination of the traditional techniques combined with MALDI-TOF MS enabled a deeper investigation. Additional aspects such as the molecular weight distributions along with known information about crystallinity and morphology of the catalyst provide a comprehensive study of carbonaceous material. Polymeric carbon and very large polycyclic aromatic hydrocarbons constitute hard carbon and can be observed with minimal sample preparation procedures. The evolution of the HTFT catalysts was investigated as a function of time-on-stream. This enabled us to study the effects of increasing amounts of hard carbon on the activity and the chemical and physical properties of the catalysts. The catalyst activity was found to decrease with increasing hard carbon content, although the effect of carbon deposition cannot be distinguished from phase transformation (oxidation) which occurs simultaneously. A method to quantify the amount of hard carbon, which progressively builds up on the catalyst, was demonstrated. This required a great deal of method development, which provides a platform for future investigations of these catalysts. Importantly, it allows predictions of the amounts of carbon that will be deposited after a certain reaction time. This allows more efficient regulation of catalyst replacement. The production of fine carbon-rich particles in the industrial reactor poses a major problem in the process. Carbon deposition leads to an increase in particle diameter with time on-stream. Permissible levels of hard carbon were identified, beyond which the mechanical strength of the catalyst particles deteriorate. This leads to break-up of the particles and therefore fines formation. The surface area and pore volume generally increase with progressive deposition of hard carbon, while the bulk density of the catalyst material exhibits a linear decrease with carbon build-up. A mechanism is proposed for hard carbon formation which apparently occurs through the dissociative adsorption of CO to form a carbon monolayer. This is followed by polymerisation of the carbon atoms. Meta-stable interstitial carbides are formed at the iron-carbon interface. Owing to a carbon concentration gradient between the top of the surface and the bottom of the metal or carbide particle, carbon diffusion across the crystal (carbide decomposition) and grows as a PAH molecule lifting the iron carbide away from the particle. As this corrosion process is intrinsic to iron-based catalysts, a catalyst that contains sulphur is proposed for future development.
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Risk assessment of organochlorine pesticides and polycyclic aromatic hydrocarbons in fish collected from fish ponds in the Pearl River DeltaKong, Kai Yip 01 January 2004 (has links)
No description available.
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Gas Phase Infrared Spectra Of Some PAHs And Diols : Experiment And TheoryDas, Prasanta 07 1900 (has links) (PDF)
In this thesis, I report the gas phase infrared spectra of some polycyclic aromatic hydrocarbons (PAHs) namely 1, 5-, 1, 6-, and 2, 6-dimethyl naphthalenes (DMNs); 2, 4-, 2, 6-, 2, 7-, and 2,8-dimethyl quinolines (DMQs); and 1, 9-, 2, 4-, and 3, 9-dimethyl phenanthrenes (DMPs) and diols such as 1, 2-ethylene glycol (1,2-EG) and 1, 4-butanediol (1,4-BD). Assignment of the IR spectra has been done with the help of DFT calculations followed by scaled quantum mechanical force field calculations.
Chapter 1 gives a brief introduction to PAHs and diols. A brief survey of literature pertinent to their sources, their importance, experimental techniques for identification of PAHs and different conformers of diols and intramolecular interactions between the two hydroxyl groups in the diols are presented. The scope and motivation of the present investigation have been described at the end of the chapter.
In Chapter 2, I have discussed all the methods used in carrying out this work. The details of the experimental FT IR set-up and quantum-chemical calculations employed in this work have been elaborated in this chapter.
The subsequent chapters 3 - 5 deal with the experimental and theoretical results obtained for DMNs, DMQs, and DMPs. In chapter 3, infrared spectra of 1,5-, 1,6-, and 2,6-DMN have been described. The spectra have been recorded using a multi-pass gas cell coupled with Nexus-870 spectrometer (Thermonicolet, US). Qualitatively, spectral assignments have been made with the help of calculated doubly scaled (one scaling factor for the C-H stretching and another factor for the non C-H stretching frequencies) harmonic frequencies at the B3LYP/6-31G* level of theory. The spectral features to distinguish three different isomers of DMN have been identified. In chapter 4, IR spectra of 2,4-, 2,6-, 2,7-, and 2,8-DMQ in the gas phase have been recorded using a high resolution Vertex-70 (Bruker Optics, Germany) FT-IR spectrometer. DFT calculations have been carried out in order to get harmonic and anharmonic frequencies and their intensities at the B3LYP/6-31G* level of theory. Unambiguous assignments of IR bands could not be made with the help of anharmonic or selectively scaled harmonic frequencies. Therefore, scaled quantum mechanical (SQM) force field calculations were performed where force fields in local coordinates were scaled for getting frequencies in close agreement with experiment. Potential energy distributions (PEDs) of the normal modes in terms of the local coordinates of the molecule using a modified UMAT program in the QCPE package were also obtained in order to identify the nature of the fundamental vibration modes. In chapter 5, I have presented the gas phase IR spectra of 1,9-, 2,4-, and 3,9-DMP. The harmonic and anharmonic frequencies and their intensities were obtained at the B3LYP/6-31G* and B3LYP/6-311G** levels of theory. I have carried out SQM calculations for the assignment of the experimental frequencies in a similar fashion as was done for the DMQs.
In chapter 6, IR spectra of two diols namely 1,2-ethylene glycol and 1,4-butane diol are reported and discussed. DFT calculations have been carried out for the harmonic fundamental frequencies and intensities at the experimental temperatures with 10 unique chosen conformers of the diols at the B3LYP/6-311++G** level of theory. Gas phase equilibrium population analysis has been done in order to generate the theoretical spectrum with the weighted average contributions from the 10 conformers to match the experimental spectrum. The hydrogen bond enthalpy, strength and nature have been investigated in details. From this experimental and theoretical studies, it has been concluded that the intramolecular hydrogen bond is absent in 1,2-EG at ordinary temperatures whereas it is present in 1,4-BD.
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Chapter 7 is the concluding chapter where the main work done in this thesis is summarized and future direction is presented.
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The Impacts of Petrochemical Activity and Climate Change on Polycyclic Aromatic Hydrocarbon (PAH) Deposition to Lake Sediments of Northwestern CanadaDesjardins, Cyndy January 2015 (has links)
With the rising demand for fossil fuels, Northern Canada has seen an unprecedented increase in petrochemical development. These developments are often associated with emissions of PAHs, a group of hydrophobic organic contaminants that are known to be carcinogenic and otherwise harmful to humans. Due to their hydrophobic nature, PAHs tend to bind to organic matter and can be produced through both anthropogenic and natural processes, making them ubiquitous in the environment. Therefore, in addition to impacts from petrochemical developments, changes to climatic conditions, such as increased forest fire disturbance and primary production also have the potential to alter delivery of organic carbon (OC) and PAHs to ecosystems. However, very little is known as to how the combined stressors of climate change and petrochemical development may affect environmental deposition of these contaminants. The concentrations and composition of parent and alkyl PAHs were analysed in radiometrically-dated sediment cores from lakes with one of four different types of petrochemical development in their catchments: (1) in-situ oil sands extraction (Cold Lake, AB); (2) open-pit oil sands extraction (Fort McMurray, AB); (3) abandoned conventional natural gas exploration (Mackenzie Delta Uplands, NWT); and (4) conventional gas and oil extraction (Cameron Hills, NWT). PAH deposition to lake sediments was also compared to climate reconstructions using climate proxies (diatom assemblages, inferred chlorophyll a and its diagenetic products, and Rock Eval carbon fractions as well as %OC). PAH sources were differentiated between potential pyrogenic and petrogenic origin over a period that extends to pre-industrial times using ratios of specific PAHs that can be traced to their potential source. Sediment cores from Cold Lake, AB showed concentrations of the sum of alkyl PAHs greater than those of parent PAHs, while all other cores show the reverse trend. A comparison of the % change of PAH concentrations from pre-development to post-development sediments between the four regions, showed that the greatest increase in concentrations of PAHs occurred in the Athabasca oil sands region. PAH profiles in the conventional regions have been historically dominated by mixed sources (pyrogenic PAHs from general background atmospheric inputs and petrogenic PAHs from the surrounding hydrocarbon-rich soils). While cores from the Fort McMurray area show a clear shift from pyrogenic sources (primarily wood and coal burning) in earlier sediments to petrogenic sources in more modern sediments, and the Cold Lake cores show some shifting sources to those dominated by pyrogenic sources in modern sediments. Organic carbon was significantly correlated with the sum of parent PAHs in 2 out of the 6 NWT cores that were examined for climate change impacts, while all other PAH parameters (concentration and composition) do not correlate significantly with any of the climate proxies. Establishing background concentrations and sources of PAHs in aquatic ecosystems is essential for understanding the natural environmental variations in these contaminants. Moreover, as both petrochemical activity and impacts from climate change are predicted to intensify in the future, studies such as this one allow us to build a solid understanding of how PAH deposition to northern lakes has responded to the warming climate and whether PAHs have been altered as a result of petrochemical activity.
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Modélisation du devenir des micropolluants organiques au cours de la digestion anaérobie de boues contaminées / Modeling the fate of micro ollutant organics during anaerobic digestion of contaminated sewage sludgeDelgadillo Mirquez, Liliana Rocio 02 December 2011 (has links)
Beaucoup de micropolluants organiques sont présents dans les boues. Leur possible impact sur l'environnement contribue à accroître leur intérêt scientifique et social. La digestion anaérobie présente un potentiel certain pour dégrader ces composés. Dans ce travail, il a été développé un modèle dynamique pour décrire le devenir de micropolluants hydrophobes au cours de la digestion anaérobie de boues contaminées. Le modèle est basé sur une distribution des composés dans quatre-compartiments et il a démontré que la transformation des micropolluants est bien simulée si l'on considère une cinétique de co-métabolisme pour la dégradation et si la phase aqueuse constitue le compartiment biodisponible. Dans ce modèle, la sorption des micropolluants hydrophobes est envisagée sur deux phases différentes: la matière particulaire et la matière dissoute/colloïdale (DCM), car la sorption sur le compartiment DCM peut influencer la disponibilité des composés et donc leur biodégradation. Il a été conclu que le transfert de micropolluants hydrophobe ne limite pas leur biodégradation, et que leur devenir est régi par l'état d'équilibre de sorption-désorption. Afin d'identifier quelle(s) étape(s) de la digestion permet le co-métabolisme, de nouvelles expérimentations ont été menées en utilisant des inhibiteurs des Méthanogènes. Elles suggèrent que la dégradation anaérobie des micropolluants implique principalement des microorganismes non-méthanogènes. En effet, la transformation co-métabolique des micropolluants serait principalement liée à la population acidogènes, comme le montre le modèle avancé proposé. Le modèle proposé est potentiellement utile pour mieux comprendre la distribution des micropolluants, prédire leur devenir dans des conditions anaérobies et aider à optimiser le processus de fonctionnement pour leur épuisement. / Many organic micropollutants are present in sludge. Their possible impact on the environment contributes to their increasing scientific and social interest. Anaerobic digestion has been shown as a potential biological process for removing these compounds. In this work, a dynamical fate model is developed for hydrophobic micropollutant under anaerobic digestion of contaminated sludge. The model is based on a four-compartment distribution and demonstrated that the micropollutant transformation is well simulated if considering a co-metabolic kinetic and the aqueous phase as the bioavailable compartment. In this model, the sorption of hydrophobic micropollutants is considered on two different phases: particulate matter and dissolved/colloidal matter (DCM). Indeed, the sorption onto DCM can influence the availability of compounds for biodegradation. It was concluded that hydrophobic micropollutant transfer does not limit their biodegradation, and that their fate is governed by sorption-desorption equilibrium state. In order to evaluate which step of the anaerobic pathway is implied in the co-metabolism of micropollutants, experimental set-ups were designed using different way to inhibit the Methanogens. The experimental inhibition of methanogenic activity suggests that the anaerobic degradation of micropollutants mainly involves non-methanogenic microorganisms. Indeed, the co-metabolic transformation of micropollutants would be mainly linked to acidogens population as it was shown through the proposed advanced model. This latter is potentially useful to better understand the micropollutant distribution, predict their fate under anaerobic condition and help to optimize the operation process for their depletion.
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Optimization of solid-phase extraction (SPE) as sample preparation for oil samples in forensic investigations.Chang, Aamanda January 2021 (has links)
Oil spills, especially in water have happened throughout the years. The consequences from this kind of incident have always been a threat to marine life and take a lot of money and time to clean up. The forensic investigations of oil usually focus on oil spill in water, however, this kind of investigation can be applied on more areas, such as in sexual offense cases and arson. The oil from the crime scene and the oil from the suspected source are analyzed and compared to each other to see if the compositions match. The aim of this thesis was to optimize the clean-up process of heavy fuel oil (HFO) using solid-phase extraction (SPE) according to the European Committee for standardization (CEN) 15522-2 method. HFOs are black oils, containing particles and soot which will decrease injector performance. Thus, a cleanup procedure is attractive when analyzing such samples. The three factors of optimization in this study were elution volumes, solvents, and SPE sorbents.The SPE method used in this study was to use the cartridges as a filter; therefore, the samples were both loaded and eluted with an organic solvent, in this case dichloromethane (DCM) or dichloromethane/heptane (DCM/Hp). The gas chromatography mass spectrometry (GC-MS) analysis method used is described in Annex B in the CEN 15522-2 method.Concluding, increasing the eluent volume did not indicate improvement on the extraction method. In terms of the solvents, both dichloromethane and dichloromethane/heptane showed similar results. The percentage weathering plots (PW-plots) showed that the SPE sorbents (dual layer florisil/Na2SO4, florisil and silica gel sorbents) worked similar. The overall conclusion from this thesis work was that further optimization must be made before implementing the method.
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Stanovení obsahu organických sloučenin v pevném uhlíkatém zbytku / Determination of content of organic compounds in biocharNovotná, Martina January 2020 (has links)
Biochar is created during the pyrolysis of organic biomass. Once added into the soil, it can improve its features. Biochars made from sewage sludge have various compositions. It is because of the vast difference between entrance materials. Organic pollutants can be absorbed into its surface during the cooling proces sof pyrolysis. If released into the enviroment, these compounds can cause inhibition of plant growth, get into food chains and adversely affect living organisms. Organic pollutans are determined most often by GC/MS after organic solvent extraction.
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