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Bário (Ba), cádmio (Cd), cromo (Cr), cobre (Cu), níquel (Ni), chumbo (Pb), selênio (Se) e zinco (Zn) no ambiente canavieiro adubado com composto de lodo de esgoto / Barium, cadmium, chromium, copper, nickel, lead, selenium and zinc in the sugarcane environment fertilized with compost of sewage sludgePöppl Neto, José Carlos 27 September 2013 (has links)
Para o uso agrícola de composto de lodo de esgoto, há escassez de informações sobre os elementos Ba, Cd, Cr, Cu, Ni, Pb, Se e Zn, que podem contaminar o ambiente. Os elementos Ba, Cd, Cr, Ni e Pb, metais pesados e o Se, um ametal, de modo geral, têm sido pouco avaliados, principalmente pelos baixos teores no solo e na planta. Dessa forma, com o presente estudo, objetivou-se avaliar os teores de Ba, Cd, Cr, Cu, Ni, Pb, Se e Zn no solo e na cultura da cana-açúcar em função da aplicação de composto de lodo de esgoto. O experimento foi conduzido em área comercial de produção de cana-de-açúcar, primeira cana soca cultivada em Argissolo Vermelho distrófico. Foram aplicadas quatro doses de composto de lodo (0; 14,7; 29,4 e 44,5 t ha-1, base seca), quatro de nitrogênio (0, 36,3 ; 72,6 e 110 kg ha-1) e duas de P2O5 (0, 30 kg ha-1), em delineamento experimental de blocos casualizados, em esquema fatorial 4x4x2, com três repetições. Foram aplicados 77 kg ha-1 de K2O em todas as parcelas para suprir a falta desse nutriente no composto. Os teores dos metais pesados foram determinados por espectrometria de massas com plasma acoplado (ICP-MS). A aplicação dos fertilizantes minerais nitrogenado e fosfatado não resultou em incremento nos teores dos metais pesados no solo e na planta. A aplicação do composto resultou em incremento de duas vezes nos teores iniciais de Zn no solo e na planta. Para Cd, Ni, Pb e Se, houve aumento nos teores do solo e da planta, em faixas que variam de 12% a 60%, em relação ao tratamento sem composto. Para o Cu, foi observado um incremento de 13% no solo, porém sem alterar o teor na planta. Os teores Ba e Cr no solo e na cana-de-açúcar não foram alterados pela aplicação do composto de lodo de esgoto. Para todos os elementos, os teores observados estiveram dentro da faixa considerada normal para solo e planta. A aplicação de composto de lodo de esgoto, dentro dos critérios técnicos e no modelo de condução do experimento de um ano de cultivo, não resulta em contaminação do ambiente canavieiro pelos elementos avaliados / For agricultural use of sewage sludge compost, there is few information on the elements Ba, Cd, Cr, Cu, Ni, Pb, Se and Zn, that can contaminate the environment. The elements Ba, Cd, Cr, Ni and Pb, heavy metals, and the Se, one nonmetal, generally have been little evaluated especially by low levels in soil and plant. The present study objected to evaluate the effects of application of sewage sludge compost on the content of Ba, Cd, Cr, Cu, Ni, Pb, Se and Zn in soil and the sugar cane. The experiment was conducted in a commercial area of production of sugarcane, first ratoon cane, cultivated in a Rhodic Paleudalf. There were applied four doses of sludge compost (0, 14.7, 29.4 and 44.5 t ha-1, dry basis), four of N rates (0, 36.3, 72.6 and 110 kg ha-1) and two of P2O5 (0 and 30 kg ha-1), in a randomized block design in a factorial scheme 4x4x2 with three replications. Were applied 77 kg ha-1 of K2O in all plots to supply the lack of this nutrient in the compost. The concentration of heavy metals were determined by inductively coupled plasma mass spectrometry (ICP-MS). The rates of nitrogen and phosphate fertilizers did not result in increase in concentration of heavy metals in soil and plant. The compost application rates resulted in an increase of twice the initial concentration of Zn in soil and plant. The concentration of Cd, Ni, Pb and Se increased in soil and plant, ranging from 12% to 60%, compared to treatment without compound. For Cu, there was a 13% increase in the soil, without changing in the plant. The concentration of Ba and Cr in soil and sugarcane were not altered by the application of compost of sewage sludge. For all elements, the levels found were within the range considered normal for soil and plant. The application of sewage sludge compost, following the technical criteria and the model of conducting the experiment of one year of cultivation, does not result in contamination in the sugarcane environment by the elements evaluated
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Dégradation photochimique et biodégradation des colloïdes organiques dans les eaux de surface boréales / Photochemical degradation and biodegradation of organic colloids in boreal watersOleinikova, Olga 01 February 2018 (has links)
La matière organique dissoute (MOD) est un composant important des eaux naturelles, déterminant la forme des éléments et les émissions de gaz à effet de serre (CO2, CH4), et influence la biodiversité des milieux des eaux. Les eaux boréales sont connues pour être généralement riches en fer, et cela est vrai en particulier pour les eaux de la région étudiée (Carélie du Nord, Russie). Le fer est associée aux MOD dans les complexes de bas poids moléculaire et les colloïdes organo-ferreux de haut poids moléculaire, qui agissent comme les principaux transporteurs d'éléments traces métalliques dans le continuum hydrologique typiques de cette région : sol - marais - rivière - lac. La transformation des colloïdes organo-ferreux se fait sous l'influence de deux facteurs principaux: la dégradation bactérienne et la dégradation photochimique. Cette étude est consacrée à l'analyse du comportement du carbone organique dissous (COD) et des éléments traces (ET) des eaux de surface en zone boréale sous l'influence de l'activité métabolique des bactéries hétérotrophes et de l'oxydation photolytique des MOD sous l'effet de la lumière du soleil. Dans les expériences, un lixiviat de tourbière, un échantillon d'eau de marais, un échantillons d'eau de ruisseaux, un échantillon de rivière, un échantillon d'eau de lac humique, un échantillon d'eau de lac oligotrophique et un pluvio-lessivat collecté sous un pin, échantillons dans lesquelles dominent les MOD de nature humique, ont été utilisés comme substrats. Des expériences en laboratoire utilisant des communautés monosouches de bactéries aérobies hétérotrophes Pseudomonas aureofaciens et Pseudomonas saponiphila (prélevées sur le territoire de Carélie) ont permis d'établir que la MOD allochtone des milieux aquatiques en zone boréale possède une forte résistance à l'activité des bactéries étudiées. Le taux de minéralisation bactérienne du COD était de 0 à 4.3 mgC.L-1.jour-1 selon le substrat, et la fraction de faible poids moléculaire (<1 kDa) de la MOD est plus susceptible de destruction que celle de poids moléculaire élevé (de 1 kDa à 0.22 µm). L'interaction des bactéries avec divers substrats aqueux a montré pour une large gamme d'éléments (Al, Fe, Mn, Ni, Co, Cu, Cd, REE, U) une prédominance significative d'une adsorption rapide sur la surface cellulaire observée lors de la première heure d'expérience (t < 1h) par rapport à une diminution lente observée lors de la suite de l'expérience (1h < t < 96h), diminution lente lié à l'assimilation intracellulaire des métaux et à la coprécipitation extracellulaire des éléments avec des hydroxydes de Fe et Al. L'analyse de divers substrats a montré une augmentation de l'adsorption des métaux avec le rapport DOC/Fe dans la solution initiale, ce qui peut être due à la compétition entre Fe et d'autres cations métalliques pour les sites d'adsorption anioniques des surfaces des cellules bactériennes. Le suivi des dynamiques d'élimination des métaux des solutions expérimentales pendant 96 heures n'a pas mis en évidence de lien entre l'élimination des métaux et le pH et les valeurs absolues de concentration de DOC et de Fe. Une relation a été établie entre la diminution lente (96 h) des éléments et le degré initial de sursaturation de la solution en oxydes et hydroxydes de fer et d'aluminium. Des expériences en conditions naturelles avec des échantillons d'eau de rivière et de marais a montré que la destruction photolytique de la MOD est beaucoup plus efficace pour l'eau de marais. / Dissolved organic matter (DOM) is an important component of natural waters, determining the form of elements and the emission of greenhouse gases (CO2, CH4), as well as affecting water biodiversity. A feature of boreal waters, and in particular the study area waters (North. Karelia, Russia), is high concentration of Fe (III), associated with DOM in low-molecular complexes and in high-molecular organo-ferric colloids, which act as the main carriers of metallic trace elements in the most typical hydrological continuum soil - bog - river - lake. The transformation of organo-ferric colloids occurs under the influence of two main factors: bacterial and photochemical degradation. The present study is devoted to the analysis of dissolved organic carbon (DOC) and trace elements (TE) behavior in surface waters of the boreal zone under the influence of the heterotrophic bacteria metabolic activity and photolytic oxidation of DOM under sunlight exposure. For the purpose of experiments there were used substrates with predominate allochthonous DOM of humic nature, including peat leachate, pine crown throughfall, fen, humic lake, stream, river and oligotrophic lake. An experiment carried out in laboratory conditions using monocultures of heterotrophic aerobic bacteria Pseudomonas aureofaciens and Pseudomonas saponiphila (isolated on the territory of Karelia) allowed to establish that allochthonous DOM of the boreal zone reservoirs possesses high resistance to the activity of the explored bacteria. The rate of bacterial mineralization of DOC was observed in range from 0 to 4.3 mgC L-1day-1, depending on the substrate, and the low molecular weight fraction (<1 kDa) of DOM was found to be more prone to destruction than high molecular weight (from 1 kDa to 0.22 µm). The interaction of bacteria with various aqueous substrates showed a significant predominance of short-term (< 1 h) adsorption on the cell surface for a wide range of elements (Al, Fe, Mn, Ni, Co, Cu, Cd, REE, U) over a long term (1 h - 96 h) intracellular uptake of metals and extracellular coprecipitation of elements with Fe and Al hydroxides. Among different substrates, there was an increase in the adsorption with the increase of DOC/Fe ratio in solution, which can be linked to a competition between Fe and metal cations for anionic adsorption sites on cell surface. The long-term removal of dissolved metals did not show any link to pH, DOC, and Fe concentration.
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Particulate and gaseous emissions from residential biomass combustionBoman, Christoffer January 2005 (has links)
<p>Biomass is considered to be a sustainable energy source with significant potentials for replacing electricity and fossil fuels, not at least in the residential sector. However, present wood combustion is a major source of ambient concentrations of hydrocarbons (e.g. VOC and PAH) and particulate matter (PM) and exposure to these pollutants have been associated with adverse health effects. Increased focus on combustion related particulate emissions has been seen concerning the formation, characteristics and implications to human health. Upgraded biomass fuels (e.g. pellets) provide possibilities of more controlled and optimized combustion with less emission of products of incomplete combustion (PIC´s). For air quality and health impact assessments, regulatory standards and evaluations concerning residential biomass combustion, there is still a need for detailed emission characterization and quantification when using different fuels and combustion techniques.</p><p>This thesis summarizes the results from seven different papers. The overall objective was to carefully and systematically study the emissions from residential biomass combustion with respect to: i) experimental characterization and quantification, ii) influences of fuel, appliance and operational variables and iii) aspects of ash and trace element transformations and aerosol formation. Special concern in the work was on sampling, quantification and characterization of particulate emissions using different appliances, fuels and operating procedures.</p><p>An initial review of health effects showed epidemiological evidence of potential adverse effect from wood smoke exposure. A robust whole flow dilution sampling set-up for residential biomass appliances was then designed, constructed and evaluated, and subsequently used in the following emission studies. Extensive quantifications and characterizations of particulate and gases emissions were performed for residential wood and pellet appliances. Emission factor ranges for different stoves were determined with variations in fuel, appliance and operational properties. The emissions of PIC´s as well as PM<sub>tot</sub> from wood combustion were in general shown to be considerably higher compared to pellets combustion. PAH<sub>tot</sub> emissions were determined in the range of 1300-220000 µg/MJ for wood stoves and 2-300 µg/MJ for pellet stoves with phenantrene, fluoranthene and pyrene generally found as major PAH´s. The PM emissions from present residential appliances was found to consist of significant but varying fractions of PIC´s, with emissions in the range 35-350 mg/MJ for wood stoves compared to 15-45 mg/MJ for pellet stoves. Accordingly, the use of up-graded biomass fuels, combusted under continuous and controlled conditions give advantageous combustion conditions compared to traditional batch wise firing of wood logs. The importance of high temperature in well mixed isothermal conditions was further illustrated during pellets combustion to obtain complete combustion with almost a total depletion of PIC´s. Fine (100-300 nm) particles dominated in all studied cases the PM with 80-95% as PM1. Beside varying fractions of carbonaceous material, the fine PM consisted of inorganic volatilized ash elements, mainly found as KCl, K<sub>3</sub>Na(SO<sub>4</sub>)<sub>2</sub> and K<sub>2</sub>SO<sub>4</sub> with mass concentrations at 15-20 mg/MJ during complete combustion. The importance of the behavior of alkali elements for the ash transformation and fine particle formation processes was further shown, since the stability, distributions and compositions also directly control the degree of volatilization. In addition to the alkali metals, zinc was found as an important element in fine particles from residential biomass combustion. Finally, the behaviour of volatile trace elements, e.g. Zn and Cd, during pellets production and combustion were studied. A significant enrichment in the pellet fuel during the drying process was determined. The magnitude and importance of the enrichment was, however, relative small and some alternative measures for prevention were also suggested.</p>
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<i>Chlamydia pneumoniae</i> in Aortic Valve Sclerosis and Thoracic Aortic Disease : Aspects of Pathogenesis and TherapyNyström-Rosander, Christina January 2002 (has links)
<p>The obligate intracellular bacterium <i>Chlamydia pneumoniae (Cp</i>), a common human pathogen, has been associated with atherosclerotic cardiovascular disease. The aetiology of non-rheumatic aortic valve sclerosis has, however, not been clarified. In two prospective studies of 42 and 46 patients undergoing surgical valve replacement because of aortic valve stenosis, the presence of <i>Cp </i>DNA could be demonstrated by polymerase chain reaction (PCR) in 49% and 35% of the sclerotic valves as compared to 9 % and 0%, respectively, of valves from forensic control cases with no heart valve disease. Some inflammatory and infectious diseases are associated with trace element changes. Eleven of 15 trace elements showed changed concentrations in sclerotic valve tissue compared to control valves in support of an active process in the sclerotic valves. Notable was an increased iron concentration in the patients´ valves suggesting a possible link to <i>Cp</i>. Furthermore, a disturbed trace element balance existed in the patients´ sera, the pattern of which was compatible with ongoing infection. In a prospective study of 38 patients operated on for thoracic aortic aneurysm or dissection, <i>Cp</i> DNA <i>w</i>as detected byPCR in 12 % of the aneurysms and the result was confirmed byelectron microscopy(EM<i>).</i> In none of the dissection patients could <i>Cp </i>be demonstratedin the removed tissues. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for doxycycline and azithromycin increased with longer <i>Cp </i>preincubation times when tested in vitro<i>.</i> EMwas performed to visualise the inactivation at a cellular level.Thus, the results demonstrate <i>Cp </i>in the tissues in non-rheumatic aortic valve sclerosis and in thoracic aortic aneurysm but not in aortic dissection.</p>
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Trace elements in soils and vegetables in a periurban market garden in Yunnan Province (P.R. China): evaluation and experimentation / Eléments en trace dans les sols et les légumes dune zone maraîchère périurbaine de la Province du Yunnan (RP de Chine) : évaluation et expérimentationZu, Yanqun 19 September 2008 (has links)
This research was conducted in order to evaluate natural trace element (TE) contents and anthropogenic contamination in soils and vegetables in Chenggong County (Yunnan Province, China). In this way, trace element contents in soils have been analysed to assess TE contamination in soils and vegetables, and transfer of TE from soil to vegetables. Agricultural practises have been proposed to amend the quality of vegetables.
We identified three geomorphopedological units: lacustrine unit, transition unit and mountain unit.
In the mountain unit, soil texture is clay more often from the weathering of limestone and marlstone. Soil colour is red or reddish brown with acid reaction.
In the transition unit, soil texture is loamy clay. Soil colour is red-brown with acid reaction.
In the lacustrine unit, soil texture mainly is sandy developed from lacustrine-alluvial deposits. Soil colour is brown and is slightly acid.
Total TE contents in the topsoil are higher than usual and even Kunming Prefecture soil. TE contents indicate a high contaminated level when considered globally. Pb, Cd and Zn present however individually low contaminated levels, and Cu presents a medium contaminated level. TE contents decrease from northeast to southwest, which is consistent with the elevation gradient. Significant differences of TE contents are observed according to distance from Chenggong town in the lacustrine unit and with distance from the mountain in the transition unit. TE accumulation is usually observed along roads. TE contents in subsoil are related to soil colour, texture, parent materials and mottles. Accumulation of Pb and Zn in topsoil and of Cu and Cd in subsoil are observed.
The highest contents are observed for Pb in cauliflower, Cd in lettuce and Chinese cabbage, and Cu and Zn in pea. The order of TE accumulation in plants varies according to the plant species and organ. According to relations between TE contents in Chinese cabbage and extraction sequential fractions of TE in soils, different soil fractions are suggested as soil assessment indicators.
Lime and pig manure have been applied to modify the soil pH and to decrease the mobility of TE in situ. With increasing in lime rate and pH, contents of acetic-acid extractable TE fractions in soil decrease. Enrichment coefficients related to TE availability (AEC) of Pb and Cu are stable and are not changed by lime or pig manure. AEC of Cd and Zn which are high in low pH, decrease with increased pH and application rates of lime and pig manure.
When application rates of lime and pig manure increase, TE contents in Chinese cabbage decrease and biomass of Chinese cabbage increases. Application rates of lime and pig manure are recommended, but their quality should also be taken into account.
/
Cette recherche a pour objet l'étude de la teneur naturelle en éléments traces métalliques (ET) et de la contamination anthropique des sols et des productions légumières dans le Comté de Chenggong (Province du Yunnan, RP de Chine).
Pour cela, la variabilité des teneurs en fonction des conditions géomorphopédologiques a été analysée, ainsi que les transferts des ET du sol vers les végétaux. Cette approche a permis ensuite d'aborder l'évaluation de la qualité des sols et des légumes, puis de proposer des pratiques agricoles alternatives dans le but d'améliorer la qualité des légumes produits.
La zone d'étude a été divisée en 3 unités géomorphopédologiques:
unité de montagne où les sols brun rouge à rouge résultent notamment de l'altération de calcaires et de marnes. Une texture argileuse et une réaction acide dominent.
unité de piedmont (dite de transition) où les sols de couleur jaune clair à jaune rougeâtre résultent principalement de l'altération de grès et de shales. Une texture limono-argileuse en surface et argileuse en profondeur, ainsi quune réaction acide dominent.
unité lacustre, à proximité du Dianchi Lake, dont les sols de couleur brun foncé sont essentiellement développés à partir de sédiments lacustres. Une texture sableuse domine en surface, ainsi qu'une réaction faiblement acide à neutre.
Les teneurs en ET rencontrées en surface des sols de la zone d'étude sont plus élevées que les teneurs moyennes observées dans les sols du monde ou même de la préfecture de Kunming. Evaluées séparément pour chaque ET, les teneurs rencontrées correspondent à des niveaux de contamination jugés faibles pour Pb, Cd et Zn, moyen pour Cu. Considérées simultanément, ces teneurs permettent de déterminer un indice de contamination global correspondant à un niveau de contamination élevé. Les teneurs en ET décroissent globalement du nord-est vers le sud-ouest, suivant le gradient d'altitude. Ces teneurs varient également de façon significative en fonction de l'éloignement de la montagne dans l'unité de transition et de l'éloignement de l'agglomération de Chenggong dans l'unité lacustre . Une accumulation en ET est souvent observée le long des routes. Dans le sous-sol, les teneurs en ET sont liées à la couleur, à la texture, au matériau parental, et aux marques d'altération. Les teneurs sont plus élevées en surface pour Pb et Zn, et en profondeur pour Cu et Cd.
Les teneurs les plus élevées pour Pb sont observées dans le chou-fleur, pour Cd dans la laitue et le chou chinois, pour Cu et Zn dans le pois.L'ordre d'accumulation des ET dans la plante dépend de l'espèce et de l'organe considérés. En fonction des corrélations observées entre les teneurs du chou chinois et les résultats obtenus avec différentes modalités d'extraction des ET du sol, des indicateurs d'évaluation de la qualité du sol ont été proposés.
Un amendement carbonaté et du fumier de porc ont été épandus afin de réduire in situ la mobilité des ET. L'augmentation de l'apport d'amendement carbonaté permet d'augmenter le pH du sol et de diminuer la fraction extraite avec l'acide acétique dilué (AA) pour chaque élément. Les AEC, rapports teneur dans la plante : teneur dans le sol extractible à lAA, sont stables pour Pb et Cu et ne sont modifiés par aucun des 2 apports. Cependant, les AEC de Zn et de Cu, élevés quand le pH du sol est acide, diminuent si le pH devient plus alcalin, ainsi qu'avec les apports d'amendement carbonaté et de fumier de porc.
Quand les apports d'amendement carbonaté et de fumier de porc augmentent, les teneurs en ET du chou chinois diminuent et sa biomasse augmente. Un épandage d'amendement carbonaté est donc recommandé. Cependant la plus grande attention doit être portée à la qualité des fumiers de porcs dont les teneurs en Zn et Cu ne sont pas négligeables.
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Chlamydia pneumoniae in Aortic Valve Sclerosis and Thoracic Aortic Disease : Aspects of Pathogenesis and TherapyNyström-Rosander, Christina January 2002 (has links)
The obligate intracellular bacterium Chlamydia pneumoniae (Cp), a common human pathogen, has been associated with atherosclerotic cardiovascular disease. The aetiology of non-rheumatic aortic valve sclerosis has, however, not been clarified. In two prospective studies of 42 and 46 patients undergoing surgical valve replacement because of aortic valve stenosis, the presence of Cp DNA could be demonstrated by polymerase chain reaction (PCR) in 49% and 35% of the sclerotic valves as compared to 9 % and 0%, respectively, of valves from forensic control cases with no heart valve disease. Some inflammatory and infectious diseases are associated with trace element changes. Eleven of 15 trace elements showed changed concentrations in sclerotic valve tissue compared to control valves in support of an active process in the sclerotic valves. Notable was an increased iron concentration in the patients´ valves suggesting a possible link to Cp. Furthermore, a disturbed trace element balance existed in the patients´ sera, the pattern of which was compatible with ongoing infection. In a prospective study of 38 patients operated on for thoracic aortic aneurysm or dissection, Cp DNA was detected byPCR in 12 % of the aneurysms and the result was confirmed byelectron microscopy(EM). In none of the dissection patients could Cp be demonstratedin the removed tissues. The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values for doxycycline and azithromycin increased with longer Cp preincubation times when tested in vitro. EMwas performed to visualise the inactivation at a cellular level.Thus, the results demonstrate Cp in the tissues in non-rheumatic aortic valve sclerosis and in thoracic aortic aneurysm but not in aortic dissection.
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Particulate and gaseous emissions from residential biomass combustionBoman, Christoffer January 2005 (has links)
Biomass is considered to be a sustainable energy source with significant potentials for replacing electricity and fossil fuels, not at least in the residential sector. However, present wood combustion is a major source of ambient concentrations of hydrocarbons (e.g. VOC and PAH) and particulate matter (PM) and exposure to these pollutants have been associated with adverse health effects. Increased focus on combustion related particulate emissions has been seen concerning the formation, characteristics and implications to human health. Upgraded biomass fuels (e.g. pellets) provide possibilities of more controlled and optimized combustion with less emission of products of incomplete combustion (PIC´s). For air quality and health impact assessments, regulatory standards and evaluations concerning residential biomass combustion, there is still a need for detailed emission characterization and quantification when using different fuels and combustion techniques. This thesis summarizes the results from seven different papers. The overall objective was to carefully and systematically study the emissions from residential biomass combustion with respect to: i) experimental characterization and quantification, ii) influences of fuel, appliance and operational variables and iii) aspects of ash and trace element transformations and aerosol formation. Special concern in the work was on sampling, quantification and characterization of particulate emissions using different appliances, fuels and operating procedures. An initial review of health effects showed epidemiological evidence of potential adverse effect from wood smoke exposure. A robust whole flow dilution sampling set-up for residential biomass appliances was then designed, constructed and evaluated, and subsequently used in the following emission studies. Extensive quantifications and characterizations of particulate and gases emissions were performed for residential wood and pellet appliances. Emission factor ranges for different stoves were determined with variations in fuel, appliance and operational properties. The emissions of PIC´s as well as PMtot from wood combustion were in general shown to be considerably higher compared to pellets combustion. PAHtot emissions were determined in the range of 1300-220000 µg/MJ for wood stoves and 2-300 µg/MJ for pellet stoves with phenantrene, fluoranthene and pyrene generally found as major PAH´s. The PM emissions from present residential appliances was found to consist of significant but varying fractions of PIC´s, with emissions in the range 35-350 mg/MJ for wood stoves compared to 15-45 mg/MJ for pellet stoves. Accordingly, the use of up-graded biomass fuels, combusted under continuous and controlled conditions give advantageous combustion conditions compared to traditional batch wise firing of wood logs. The importance of high temperature in well mixed isothermal conditions was further illustrated during pellets combustion to obtain complete combustion with almost a total depletion of PIC´s. Fine (100-300 nm) particles dominated in all studied cases the PM with 80-95% as PM1. Beside varying fractions of carbonaceous material, the fine PM consisted of inorganic volatilized ash elements, mainly found as KCl, K3Na(SO4)2 and K2SO4 with mass concentrations at 15-20 mg/MJ during complete combustion. The importance of the behavior of alkali elements for the ash transformation and fine particle formation processes was further shown, since the stability, distributions and compositions also directly control the degree of volatilization. In addition to the alkali metals, zinc was found as an important element in fine particles from residential biomass combustion. Finally, the behaviour of volatile trace elements, e.g. Zn and Cd, during pellets production and combustion were studied. A significant enrichment in the pellet fuel during the drying process was determined. The magnitude and importance of the enrichment was, however, relative small and some alternative measures for prevention were also suggested.
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Chemical Composition Of Atmospheric Particles In The Aegean RegionMunzur, Basak 01 February 2008 (has links) (PDF)
Daily aerosol samples were collected at the Ç / andarli which is located on Aegean coast of Turkey. A rural site was selected to monitor atmospheric pollution by long range transport. Sampling was performed in both summer and winter seasons, and in total 151 samples were obtained. Concentrations of elements in the samples were measured in order to identify sources and possible source locations of pollutants.
Measured concentrations of trace elements at the Ç / andarli station were compared with those measured at various sites around the world and, also in Turkey. As a result of comparison, level of pollution at the Aegean Region was found to be lower than the Mediterranean Region and Black Sea Region.
Air flow climatology at Ç / andarli was investigated in order to determine potential source regions for pollutants. Frequency of air flows from Russia and Western Europe are higher suggesting that emissions from these industrial regions affect the chemical composition of particulate matter. Besides these, it was concluded that contributions from Central and Eastern European countries are significantly high because of frequent air mass transport.
Concentrations of elements measured at Ç / andarli station were found to show short and seasonal variations. Such variations in concentrations are explained by variations in the source strengths and transport patterns.
Positive matrix factorization (PMF) was applied to determine sources of elements and contribution of sources to each element. This analysis revealed 5 sources, two local anthropogenic emissions factor, one soil factor, one sea salt factor and one long range transport factor.
Distribution of Potential Source Contribution Function (PSCF) values showed that main sources of SO42- are observed in Bulgaria, Romania, Poland, Ukraine and central part of Aegean region.
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Depositional and diagenetic processes in the formation of the Eocene Jackson Group bentonites, Gonzales County, TexasMichaelides, Michael Nicholas 17 February 2012 (has links)
Bentonite clays are exposed in Paleogene strata stretching over 650 km parallel to the Texas coastline. This study focuses on a white and blue and a yellow and brown commercial Ca-montmorillonite bentonite near the city of Gonzales, Gonzales county, Texas. The deposits have stratigraphic ages of Late Eocene (~36.7 - 32.7 Ma). The bentonites in these deposits have varying colors, purities and brightness affording them diverse industrial uses. The distribution and geologic character of the high purity white and blue bentonite suggests that the deposit represents an accumulation of volcanic ash in a secondary tidal channel during the ash-fall event. A low rate of terrigenous clastic sedimentation and rapid accumulation of fresh ash were critical to the formation of high purity clay. The lower purity yellow and brown bentonites appear to have a fluvial origin marked by higher rates of detrital sedimentation and episodic accumulation of clay and ash.
The bentonite and associated strata were studied using optical microscopy, SEM, XRD and REE analyses to constrain their textural, mineralogic, and chemical character.
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Eocene pyroclastic volcanism is well documented from sources in southwestern North America, specifically in the Sierra Madre Occidental (Mexico), Trans-Pecos (Texas) and Mogollan-Datil (New Mexico) volcanic fields. Projected Eocene wind patterns support this region as a potential source for the Gonzales bentonites. A comparison of the trace and REE fingerprints of the white and blue bentonites and the yellow and brown bentonites with data available for Late Eocene volcanics in the North American Volcanic Database provides a couple of potential matches. The strongest potential match for the Late Eocene bentonite protolith is described as a sample of silicic tuff with an age range of 32.2 – 30.6 Ma, located in the southern Mexican state of Oaxaca. While the trace and REE match is strong, the tuff is somewhat young compared to the Jackson Group sediments. In addition, the sample location is due almost directly south of the Gonzales deposits, rather than the western location expected for a Gonzales bentonite source. The other potential matches are located in New Mexico, and the Mexican state of Chihuahua. These potential matches only have 6 REE available for comparison, and require further investigation. Many Paleogene volcanic units in southern North America are undocumented with regard to REE data or precise absolute ages. As additional geochemical analyses become available for a more extensive suite of Paleogene volcanic units, stronger matches with Gulf of Mexico Basin bentonites are expected to emerge. / text
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Speleothems from Warm Climates : Holocene Records from the Caribbean and Mediterranean RegionsBoyd, Meighan January 2015 (has links)
This thesis contributes to increased knowledge on Holocene climate and environmental variability from two complex and sparsely studied areas. Using a speleothem from Gasparee Cave, Trinidad, as a paleoclimate archive, the local expression of the 8.2 ka (thousand years before 1950) climate event and associated patterns of the inter-tropical convergence zone (ITCZ) and rainfall is provided. Subsequent speleothem studies using multi-proxy analysis of stalagmites from Kapsia Cave and Alepotrypa Cave, Greece, provide records of climate, vegetation and human induced changes in the cave environment during parts of the Holocene. The speleothems from the well-studied Neolithic habitation site, Alepotrypa Cave, have produced a climate and habitation record which covers the period of 6.3-1.0 ka. The cave was inhabited between 8.0-5.2 ka and was closed by a tectonic event, which has preserved the settlement. The stable oxygen record shows the first well-dated and robust expression of the 4.2 ka dry event in the Peloponnese, places the timing of the 3.2 ka dry event within an ongoing dry period, and shows a final dry event at 1.6 ka. The North Atlantic as well as more regional drivers, such as the North Sea Caspian Pattern Index is proposed to, in a complex interplay, govern many of the climate trends and events observed. Trace element variation after the site is abandoned indicate what is interpreted as two volcanic eruptions, the Minoan eruption of Thera (Santorini) around 3.6 ka and the 2.7 ka eruption of Somma (Vesuvius). Variations in trace elements during the habitation period show clear human influence, indicating an association with specific cave activities. One of the most interesting prospects for continued work on Alepotrypa Cave is this successful marriage of speleothem studies and archeology. A framework of dates which constrain some behavior of people living in the cave is only the beginning, and there is great potential to continue finding new clues in the speleothem data. / Denna avhandling bidrar till ökad kunskap om klimatets variationer och miljön i två geografiskt skilda områden på låga breddgrader och under tidsperioder inom den Holocena epoken. Genom att använda en droppsten (stalagmit) från Gasparee-grottan, Trinidad, som ett paleoklimatarkiv, har det bland annat varit möjligt att visa att Trinidad upplevde torrare förhållanden under den snabba klimatförändring som observerats ske för 8200 år sedan på många platser i världen. Denna torrare klimatsituation i Trinidad föreslås vara ett resultat av en sydlig förflyttning av den intertropiska konvergenszonen. Övriga stalagmiter som studerats för denna avhandling kommer från Kapsia-grottan och Alepotrypa-grottan som finns på Peloponnesos-halvön i Grekland. Resultaten därifrån speglar dels klimat- och vegetationsvariatoner och dels graden av mänsklig aktivitet, under tiden för ca 8000 år sedan till för 1000 år sedan. Alepotrypa-grottan är känd för att vara en av de större Neolitiska boplatserna i Grekland. Isotop- och spårämnesanalyser av stalagmiterna har bidragit med ny kunskap om tidpunkten för mänsklig aktivitet, hur människorna påverkade grott-miljön samt hur klimatet varierat efter det att grottan, genom en tektonisk händelse, stängdes för människans inverkan. Snabba klimatförändringar, för 4200 och 3200 år sedan, observerade i andra regioner, rekonstrueras här för första gången på Peloponnesos. En snabb förändring mot torrare förhållanden observeras även för 1600 år sedan. De klimatstyrande processerna föreslås vara en kombination av storskaliga processer som den nordatlantiska oscillationen och mer regionala processer som det så kallade North Sea Caspian Pattern Index. Variationer i spårämnen i stalagmiterna efter att Alepotrypa-grottan stängdes kan kopplas till två vulkaniska utbrott, nämligen det Minoiska utbrottet av Thera på ön Santorini kring 3600 år sedan och utbrottet av Somma (Vesuvius) kring 2700 år sedan. Spårämnesvariationer under bo-perioden ger tydliga indikationer på människans påverkan på grottmiljön och som delvis kan länkas till specifika aktiviteter, som eldning av dynga i grottan. Avhandlingen är ett resultat av en framgångsrik kombination av klimatstudier och arkeologisk kunskap och utgör ett viktigt underlag för fördjupat interdisciplinärt forskningssamarbete i Alepotrypa-grottan. / <p>At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 1: Manuscript. Paper 4: Manuscript. Paper 5: Manuscript. Paper 6: Manuscript.</p>
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