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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.
91

Especiação de alumínio em águas subterrâneas na região do manancial Billings: aplicação da radiação ionizante na digestão amostral para fins analíticos e na proposta de remediação / Speciation of aluminium in groundwater on Billings dam area: applications of the ionizing radiation for digesting of water samples and proposal of remediation

YAMAGUISHI, RENATA B. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:04Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:42Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
92

Especiação de alumínio em águas subterrâneas na região do manancial Billings: aplicação da radiação ionizante na digestão amostral para fins analíticos e na proposta de remediação / Speciation of aluminium in groundwater on Billings dam area: applications of the ionizing radiation for digesting of water samples and proposal of remediation

YAMAGUISHI, RENATA B. 09 October 2014 (has links)
Made available in DSpace on 2014-10-09T12:42:04Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:04:42Z (GMT). No. of bitstreams: 0 / A represa Billings é o maior manancial superficial do Estado de São Paulo cuja importância está ligada ao abastecimento público, à geração de energia, à pesca, à recreação e ao lazer para a cidade de São Paulo e os municípios da sua região metropolitana. Nos últimos anos essa região vem sofrendo grande impacto ambiental. Apesar de ser uma APA (Área de Proteção Ambiental), há no entorno da represa, vários tipos de assentamentos cujas famílias utilizam para o seu consumo a água proveniente de poços situados, muitas vezes, a poucos metros da represa, já que inexiste o acesso à rede de saneamento básico (tratamento de água e esgoto em rede pública). De acordo com relatórios de entidades governamentais, observa-se que a espécie química alumínio está presente nas águas da represa em valores acima do permitido, o que gera preocupações relacionadas à contaminação do meio ambiente e à saúde da população; por outro lado, há poucas informações sobre a qualidade das águas subterrâneas da região. Considerando-se essa deficiência de informações, este trabalho teve como objetivo investigar a possível contaminação de poços, partindo da aplicação de um programa criado o PAMQUÁ ® - que auxiliou e direcionou à tomada de decisão a um determinado contaminante de risco à saúde humana encontrado na água e como o uso da radiação ionizante pôde ser aplicada no beneficiamento de diagnóstico químico e em solução para tratamento específico. Dessa forma, pôde-se ter o respaldo de que a espécie química alumínio é o principal contaminante daquelas águas superficiais. Como os íons alumínio são susceptíveis à complexação por substâncias orgânicas, o processo de irradiação ionizante como etapa de pré-tratamento para a determinação analítica foi um processo inovador e que foi aplicado em dois tipos de amostra: 1) amostras de água padronizadas contendo ácido húmico, que é o tipo de matéria orgânica que ocorre com frequência em águas subterrâneas e 2) amostras de água coletadas dos poços da região estudada. O processo de irradiação permitiu a redução do teor de matéria orgânica e a mineralização dessas amostras, contribuindo com dados inéditos sobre o teor de alumínio. Finalmente, foi desenvolvido um novo material - uma membrana polimérica seletiva modificada por radiação que propõe a remediação do alumínio na água. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP
93

Geoquímica inorgânica, orgânica e isotópica do enxofre em sedimentos holocênicos do sistema de ressurgência de Cabo Frio (RJ)

Díaz Ramos, Rut Amélia 07 June 2017 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2017-06-07T18:11:24Z No. of bitstreams: 1 Tese Rut Díaz.pdf: 2159528 bytes, checksum: 159d73b33fae80ff4ee36bea4366ea74 (MD5) / Made available in DSpace on 2017-06-07T18:11:24Z (GMT). No. of bitstreams: 1 Tese Rut Díaz.pdf: 2159528 bytes, checksum: 159d73b33fae80ff4ee36bea4366ea74 (MD5) / Fundação de Amparo a Pesquisa do Rio de Janeiro / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Petrobras/CENPES / Agência Nacional do Petróleo / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geoquímica, Niterói, RJ / O presente estudo utiliza a geoquímica inorgânica das espécies reduzidas do enxofre, operacionalmente definidas como acid - volatile sulfufide (AVS) e chromium -reducible sulfur (CRS),a composição isotópica ( δ 34 S) do sulfat o da água intersticial, do CRS, e das frações orgânicas (ácidos húmicos, ácid os fúlvicos e resíduo orgânico) para avaliar a diagênese do enxofre ao longo do Holoceno (últimos 12.000 anos cal AP) no Sistema de Ressurgência de Cabo Frio (SRCF) . Também foi usada a morfologia da pirita, considerando a distribuição de tamanho dos frambóides através de microscopia eletrônica de varredura (MEV), com o objetivo de inferir o estado de oxidação do ambiente de formação. Foram coletados quatro perfis sedimentares cur tos (b ox - cores ) e três longos ( kullembers ) em um gradiente “cross - shelf” na plataforma continental de Cabo Frio. A razão C/N e o a composição isotópica ( δ 13 C) da matéria orgânica reflete uma fonte marinha durante a diagênese recente. As diferentes caracter ísticas morfológicas, como as superfícies de oxidação nos microcristais, os processos de crescimento secundário e os poliframboides encontrados nas análises morfológicas da pirita, assim como também a variabilidade na distribuição dos diâmetros dos frambói des evidenciaram uma formação sob condição redox altamente dinâmica. A razão COT/CRS indica que o fator limitante para a formação da pirita é o enxofre , devido as condições de deposição do ambiente as quais favorecem a re - oxidação do sulfeto de hidrogênio. A composição isotópica do sulfato ao longo dos perfis apresenta um valor médio de +23‰, e não foi observado um fracionamento isotópico com respeito ao sulfato da água do mar (+ 21‰), indicando a diagênese do sulfato em um sistema aberto e baixas taxas de sulfato redução. No entanto, a composição isotópica do CRS apresentou sinais altamente empobrecidos em 34 S ( - 45‰ até - 25 ‰), indicando reações de re - oxidação no ciclo do enxofre. A composição isotópica das espécies orgânicas do enxofre apresenta um enrique cimento em 32 S quando comprados com o sulfato da água intersticial , e isotopicamente pesadas comparadas com a pirita. O incremento na razão S/C dos ácidos húmicos e o empobrecimento do sinal isotópico em 34 S com o avanço da profundidade indicam a captura d o enxofre de origem diagenético pela matéria orgânica. Um balanço de massa isotópico indica a predominância de uma fonte biossintética nos ácidos húmicos e diagenética nos ácidos fúlvicos, estes resultados guardam relação com a reatividade da matéria orgân ica em cada fração. No gradiente “cross - shelf” as frações orgânicas da plataforma média apresentam os menores conteúdo de enxofre biossíntetico, indicando a presença de matéria orgânica mais reativa. Estes resultados indicam que a sulfurização da matéria o rgânica e a cumulação de pirita em Cabo Frio foi favorecida pelo ciclo re - oxidativo do enxofre devido a intensas condições óxicas na coluna de água. O processo de diagênese do enxofre ao longo do Holoceno não guarda relação aparente com as mudanças oceanog ráficas registrada na área de estudo, assim sendo, adinâmica do enxofre esteve relacionada com a intensidade dos processos de diagênese / Four box-corer and tree kullemberg were collected in a cross - shelf gradient in the continental shelf of Cabo Frio. The box-corer were used to evaluated the sulfurization of the organic matter during the early diagenesis and also, study the pyrite morphology and size distribution of framboids by scanning electron microscopy (SEM) to infer the oxidation state of the environment during the early diagenesis. This study uses the inorganic geochemistry of reduced sulfur species operationally defined as acid-volatile sulfufide (AVS) and chromium - reducible sulfur (CRS), the isotopic composition ( δ 34 S) of pore water sulfate, CRS, and the isotopic composition of difference organic fraction (humic acids, fulvic acids and organic residue to evaluated the sulfur diagenesis during the Holocene (last 12000 years cal AP) in the upwelling system of Cabo Frio. Carbon stable isotopes signatures and C/N ratios of total organic matter evidence a marine source during the early diagenesis. The observed increase in the atomic S/C ratios and t he 34 S depletion in humic acids with increasing depth evidence the diagenetic uptake of reduced sulfur species by organic matter during the early diagenesis. The different morphological characteristics observed, such as surface oxidation in the microcrysta ls, the processes of secondary growth and poliframboides found, as well as the variability in the framboids diameters distribution, show the formation under highly dyna mic redox condition. In the sedi m e nts from the Holocene the COT/CRS ratio indicates that the limiting factor for the pyrite formation is the sulfur. The isotopic composition of sulfate is around +23 ‰ , and without fractionation of sulfate with respect to sea water (21 + ‰) indicating a sulfur diagenesis in a open system and a low net sulfate r eductions. The isotopic composition of the CRS is highly depleted ( - 45 ‰ to - 35‰), indicating oxida tion reactions in the cycle of sulfur . The stable sulfur isotope composition of the organic fractions ( humic acids, fulvics acids and organic res idue ) was sub stantially enriched in 32 S when compared to bottom and pore water sulfate (δ 34 S SO4 2 - ~ +23‰), but isotopically heavier than the co - existing pyrite ( δ 34 S CRS = - 45‰ to - 35‰). The 34 S depletion in humic acids, fulvis acids and in the organic residue with increasing depth evidence the diagenetic uptake of reduced sulfur species by organic matter. A sulfur isotope mass balance indicated a predominance of biogenic sulfur in humic acids and in the organic residue, while the fulvic acids has a predominance of d iagenetic sulfur. In cross - shelf gradient, the organic fractions from the middle shlelf have the lower proportion on biosynthetic sulfur, indicating the presence of more reactive matter. The results evidenced that the sulfurization of organic matter and th e p yrite accumulation in the Cabo F rio sediments was favored by the sulfur re - oxidative cycling due to the intense oxic water conditions . The diageneses process in the sulfur cycle during the Holocene in sediments from the continental shelf don’t have rela tion with the changes in the oceanography conditions. The process of diagenesis of sulfur seem to be a continuous process
94

[en] STUDY OF EFFECT FOR APLICATION TO A HUMIC COMPOUND OF MINERAL SOURCE ON HEAVY METALS PRESENTS IN SEWAGE SLUDGE / [pt] ESTUDO DO EFEITO DA APLICAÇÃO DE UM COMPOSTO HÚMICO DE ORIGEM MINERAL SOBRE METAIS PESADOS PRESENTES EM LODO DE ESGOTO

MARCUS PAULO FOURNIER LESSA 10 February 2005 (has links)
[pt] Com base no procedimento EPA-3050B, estudou-se o teor de metais (Cd, Cr, Cu, Ni, Pb, e Zn) em lodos de esgoto da CETESB. Foram analisadas duas amostras e os resultados obtidos foram (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) para primeira amostra e (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg) para segunda amostra, resultados estes inferiores aos descritos pela CETESB para amostras de lodo da mesma estação de tratamento. Dada uma potencial utilização deste material como adubo agrícola, foi determinada a fração disponível destes metais. Com exceção do níquel (25%), uma fração pequena dos metais estudados encontra-se na forma assimilável pelas plantas (< 20%), com base no procedimento descrito pela EMBRAPASolos (extração com DTPA). Os efeitos de uma eventual utilização de composto húmico mineral (CHM) como aditivo ao lodo, visando uma redução na fração assimilável de metais, foi estudada em função da quantidade de CHM aplicado e do pH da solução final. Os resultados obtidos demonstraram que o CHM possui um poder de complexação para os metais semelhante ao do DTPA e que, sua aplicação ao lodo de esgoto, teria, na realidade um efeito de potencializar a fração disponível de certos metais como o zinco. / [en] Based on the EPA-3050B procedure, the concentration of metals (Cd, Cr, Cu, Ni, Pb and Zn) in sludge source at CETESB studied. Two samples were analyzed and the results obtained were (Cd =3,4 ; Cr =367,5 ; Cu =263,0 ; Ni=290,6 ; Pb =91,5 ; Zn =1324,9 mg/ kg) and (Cd =3,0 ; Cr =332,2 ; Cu =190,5 ; Ni=274,6 ; Pb =82,5 ; Zn =1284,2 mg/ kg). These concentrations were below those descried by SABESP for sludge samples measured in the same treatment station. Due to the potential utilization of these materials as manure in agriculture, the disposal fraction of these metals was determined. Except nickel (25%), a little fraction of metals studied is assimilated by plants (< 20%), base on the procedure already descried by EMBRAPA- Solos (extraction with DTPA). The effect of an eventual utilization to humic mineral compound (HMC), as additive in sludge, aiming the reduction of the assimilated fraction of metals, were studied in function of both, the amount of HMC applied and the final pH of the solution. The results obtained showed that HMC has a complexation potential for metals similar to DTPA and that, its application in sludge, has in fact, a potential effect on the disposal fraction of metals such as zinc.
95

Effects of biostimulators on growth and physiological reactions of vegetables / tested on cucumber (Cucumis sativus L.)

Shevchenko, Yaroslav 13 January 2010 (has links)
Biotische und abiotische Stressfaktoren mindern die Quantität und die Qualität landwirtschaftlicher Erzeugnisse. Sogar die kontrollierten Wachstumsbedingungen eines Gewächshauses tragen nur bedingt zur Minderung der schädlichen Auswirkungen von suboptimalen Wachstumsfaktoren bei. Die negativen Effekte, die durch die Entstehung suboptimaler Wachstumsbedingungen auftreten können, manifestieren sich oft erst nach geraumer Zeit. Aus diesem Grund ist es wichtig, Maßnahmen zu treffen, die diesen negativen Auswirkungen entgegenwirken und eine nachhaltige Produktion von Obst und Gemüse sichern. Um die Widerstandsfähigkeit der Pflanzen gegenüber den zahlreichen Stressfaktoren zu erhöhen, werden sogenannte Pflanzenstärkungsmittel verwendet. Die zahlreichen gärtnerischen Substrate, die bei der Kultivierung von Obst und Gemüse heutzutage unentbehrlich geworden sind, besitzen verschiedene chemische und physikalische Eigenschaften. Diese Eigenschaften unterliegen dem ständigen Einfluss von verschiedenen Faktoren, insbesondere dem Pflanzenwachstum. Anderseits beeinflussen gärtnerische Substrate die Entwicklung der Pflanzen. Die Fähigkeit eines Substrates zur Wasserhaltung, sowie zur Gewährleistung einer optimalen Versorgung mit pflanzlichen Nährstoffen während der kritischen Wachstumsperioden der Pflanzen kann die Produktivität der gärtnerischen Kulturen stark beeinflussen. Dynamische Veränderungen der Substrateigenschaften während des Pflanzenwachstums und Änderungen in physiologischen Reaktionen der gärtnerischen Pflanzen können als System betrachtet werden, und als System können sie, zwecks Optimierung der pflanzlichen Systeme, beeinflusst werden. Diese Einflussnahme kann durch Verwendung von Pflanzenstärkungsmitteln verschiedener Herkunft erreicht werden. In der Fachliteratur wird häufig über Pflanzenstärkungsmittel diskutiert. Dabei wird sehr oft außer Acht gelassen, dass jedes Pflanzenstärkungsmittel ein eigenes Wirkungsspektrum besitzt. Die Breite des Wirkungsspektrums eines Pflanzenstärkungsmittels ist begrenzt, weshalb die positiven Effekte des verwendeten Mittels häufig geringer ausfallen können als erwartet. Die Arbeitshypothese dieser Arbeit belegt, dass durch die Kombination verschiedener bioaktiver Stoffe mit Pflanzenstärkungsmitteln dieses Wirkungsspektrum erweitert werden kann. Aus diesen Zusammenhängen leitet sich das Interesse an Kombinationen verschiedener Pflanzenstärkungsmittel sowie anderer bioaktiver Stoffe ab. Diese Arbeit untersucht die biologischen Effekte verschiedener Kombinationen von bioaktiven Stoffen und Pflanzenstärkungsmitteln zur Stabilisierung pflanzlicher Systeme. Als bioaktive Stoffe werden in dieser Arbeit Laktate und Humate bezeichnet, wobei Mikroorganismen als Pflanzenstärkungsmittel eingesetzt wurden. Die Ergebnisse dieser Arbeit zeigen, dass ein kombinierter Einsatz von Mikroorganismen, Humaten und Laktaten zum Einen zum Erhalt der chemischen und physikalischen Eigenschaften gärtnerischer Substrate, zum Anderen zur Stabilisierung der Pflanzen gegenüber suboptimalen Wachstumsfaktoren beiträgt. Die Anwendung der Kombination von allen drei Komponenten auf Versuchsvarianten mit Gewächshausgurken als Modellpflanze zeigte, dass die Pflanzenproduktivität bei diesen Varianten am höchsten war. Die physiologischen Reaktionen der Gurkenpflanzen im Versuch mit modellierten Stressfaktoren wurden durch Chlorophyllfluoreszenz ermittelt. Die Ergebnisse zeigten, dass die Pflanzen, die mit allen drei Komponenten behandelt wurden, gegenüber suboptimalen Wachstumsbedingungen resistent sind. Die Resultate dieser Arbeit wurden in einem gärtnerischen Unternehmen approbiert. / Biotic and abiotic stress factors reduce the quality and quantity of the horticultural produce. Even controlled growing conditions of a greenhouse can not reduce all the negative influences of the suboptimal growing factors. The negative effects caused by the suboptimal growing factors manifest themselves only after substantial period of time. That is why it is important to take steps that counter these negative effects and enable sustainable production of fruits and vegetables. To improve the resistance of the plants against different stress factors, the plant strengtheners are applied. The horticultural substrates, which are used for cultivation of the fruits and vegetables, have become unalienable and possess the range of different physical and chemical properties. These properties are subjected to constant influence of different biotic and abiotic factors; especially those resulted from the plant growth itself. On the other hand, the substrates influence the growth of the horticultural plants. The water holding capacity of the substrate and its capacity to provide plants with nutrient elements during the critical vegetation periods can influence the productivity of the plant system. Dynamic changes of the substrate properties during the plant growth and changes in physiological reactions of horticultural plants can be viewed as a system, and as the system it can be influenced for the purposes of its optimization. This influence can be achieved by application of different plant strengtheners of different origin. The role of the plant strengthening agents is being discussed in the literature. The missing point in the discussion however is the fact that the plant strengtheners have their own activity spectrum. The activity spectrum of the bioactive substance is limited and expected positive effects of its application can be lesser that expected. The hypothesis of the thesis is based on the premise that combination of the different bioactive substances and plant strengthening agents can increase the activity spectrum. These interrelations cause an interest on combinations of different plant strengtheners and others bioactive substances. This thesis investigates biological effects different combinations of bioactive substances and plant strengtheners with an aim to stabilize plant systems. In this work, lactates and humates are described as bioactive compounds, whereas microorganisms are perceived as plant strengtheners. The results of this work show that the combined application of microorganisms, humates and lactates sustain chemical and physical properties of the horticultural substrates and at the same time stabilize plant systems under the suboptimal growing factors. The experiment variants with greenhouse cucumbers as a model plant treated with all three components showed the highest productivity. Physiological reactions of the cucumber plants were investigated through measurement of the chlorophyll fluorescence of the cucumber leaves in the experiments with modeled suboptimal growing factors. The results showed that the plants treated with a combination of humates lactates and microorganism were more resistant to suboptimal growing conditions than the plants on variants without treatment. The results of this work were approbated at a horticultural enterprise.
96

Development of High-throughput Membrane Filtration Techniques for Biological and Environmental Applications / Development of High-throughput Membrane Filtration Techniques

Kazemi, Amir Sadegh 11 1900 (has links)
Membrane filtration processes are widely utilized across different industrial sectors for biological and environmental separations. Examples of the former are sterile filtration and protein fractionation via microfiltration (MF) and ultrafiltration (UF) while drinking water treatment, tertiary treatment of wastewater, water reuse and desalination via MF, UF, nanofiltration (NF) and reverse-osmosis (RO) are examples of the latter. A common misconception is that the performance of membrane separation is solely dependent on the membrane pore size, whereas a multitude of parameters including solution conditions, solute concentration, presence of specific ions, hydrodynamic conditions, membrane structure and surface properties can significantly influence the separation performance and the membrane’s fouling propensity. The conventional approach for studying filtration performance is to use a single lab- or pilot-scale module and perform numerous experiments in a sequential manner which is both time-consuming and requires large amounts of material. Alternatively, high-throughput (HT) techniques, defined as the miniaturized version of conventional unit operations which allow for multiple experiments to be run in parallel and require a small amount of sample, can be employed. There is a growing interest in the use of HT techniques to speed up the testing and optimization of membrane-based separations. In this work, different HT screening approaches are developed and utilized for the evaluation and optimization of filtration performance using flat-sheet and hollow-fiber (HF) membranes used in biological and environmental separations. The effects of various process factors were evaluated on the separation of different biomolecules by combining a HT filtration method using flat-sheet UF membranes and design-of-experiments methods. Additionally, a novel HT platform was introduced for multi-modal (constant transmembrane pressure vs. constant flux) testing of flat-sheet membranes used in bio-separations. Furthermore, the first-ever HT modules for parallel testing of HF membranes were developed for rapid fouling tests as well as extended filtration evaluation experiments. The usefulness of the modules was demonstrated by evaluating the filtration performance of different foulants under various operating conditions as well as running surface modification experiments. The techniques described herein can be employed for rapid determination of the optimal combination of conditions that result in the best filtration performance for different membrane separation applications and thus eliminate the need to perform numerous conventional lab-scale tests. Overall, more than 250 filtration tests and 350 hydraulic permeability measurements were performed and analyzed using the HT platforms developed in this thesis. / Thesis / Doctor of Philosophy (PhD) / Membrane filtration is widely used as a key separation process in different industries. For example, microfiltration (MF) and ultrafiltration (UF) are used for sterilization and purification of bio-products. Furthermore, MF, UF and reverse-osmosis (RO) are used for drinking water and wastewater treatment. A common misconception is that membrane filtration is a process solely based on the pore size of the membrane whereas numerous factors can significantly affect the performance. Conventionally, a large number of lab- or full-scale experiments are performed to find the optimum operating conditions for each filtration process. High-throughput (HT) techniques are powerful methods to accelerate the pace of process optimization—they allow for multiple experiments to be run in parallel and require smaller amounts of sample. This thesis focuses on the development of different HT techniques that require a minimal amount of sample for parallel testing and optimization of membrane filtration processes with applications in environmental and biological separations. The introduced techniques can reduce the amount of sample used in each test between 10-50 times and accelerate process development and optimization by running parallel tests.

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