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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.
1

Distribution of petroleum products with respect to boating activity in a reservoir /

Mastran, Trina Ann, January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 156-167). Also available via the Internet.
2

Effects of Grasses on the Remediation of Creosote-Contaminated Surface Soil

Crosswell, Scott Brownlee 14 May 1999 (has links)
A grass phytoremediation field study was initiated in July 1997 at the site of a former railroad tie facility that used creosote for tie preservation. The site is contaminated with polycyclic aromatic hydrocarbons (PAHs). A test matrix consisting of 36 planted (clover, fescue and rye grasses) and unplanted cells was established. The focus of the study was to evaluate PAH remediation in fertilized plots that were unplanted or seeded with clover, fescue or rye. Samples were collected from a depth of 15 to 21 cm, and the six most prevalent PAHs, acenaphthene, fluorene, phenanthrene, fluoranthene, pyrene and chrysene were quantified. Data from four sampling periods, t=0, 9, 12 and 17 months is presented. At t=9 months, substantial loss of the five lowest molecular weight (LMW) PAHs had occurred, and the loss was attributed to natural attenuation. During the first 9 months, below average precipitation at the site delayed grass root development. Between t=9 and 12 months, above average precipitation was recorded and this appeared to accelerate chrysene removal rates in both the unplanted and planted cells; however, the rate was higher rate in the planted cells. Similarly, fluoranthene and pyrene degradation seemed to be enhanced in the fescue and rye cells. Over the last 8 months of the study, acenaphthene, fluorene and phenanthrene concentrations approached constant, minimum levels suggesting additional removal will be limited. PAH compounds with higher solubility correlated to decreased constituent soil concentrations. Additional sampling was initiated at t=17 months to compare PAH concentrations with depth. This was done because the observed root mass changed significantly with depth. Samples were taken at two additional depths 10 to 15 and 32 to 38 cm. Increased removal of fluoranthene and pyrene was observed in the uppermost zone, suggesting a role for plants in remediation of these 4 ringed PAHs. / Master of Science
3

Biodegradação de naftaleno, fenantreno e diesel por isolados do gênero Burkholderia da Amazônia /

Furlan, Bianca. January 2011 (has links)
Resumo: O gênero Burkholderia compreende um grupo de bactérias muito diversificado, ocupando vários nichos ecológicos e possui espécies que causam doenças, mas outras espécies apresentam habilidades importantes para os ramos da agricultura, biotecnologia e do ambiente, como a biodegradação. Essas bactérias são morfologicamente semelhantes e o gênero está dividido em dezessete genomovars, onde espécies semelhantes geneticamente são agrupadas, formando o Complexo Burkholderia cepacia (CBC). Por meio de estudos moleculares do gene 16S rRNA e do gene recA foi possível fazer a classificação adequada em espécies dos 450 isolados obtidos da Terra Preta Antropogênica (TPA) e adjacentes, em quatro sítios (TPA Caldeirão Cultivado; TPA Caldeirão Capoeira; TPA Hatahara e TPA Mina-I), foram obtidos 177 isolados do gênero Burkholderia. Desses isolados, pela análise do gene 16S rRNA foi possível classificar 157 isolados ao nível de espécie e pela análise do gene recA somente 105 isolados foram classificados neste mesmo nível. Esses isolados foram utilizados no teste de biodegradação dos hidrocarbonetos. Os hidrocarbonetos poliaromáticos (HPAs) são compostos orgânicos resultantes da combustão incompleta da matéria orgânica e dos derivados de petróleo, são pouco solúveis em água e muito tóxicos para as células, por isso, não são metabolizados por muitos micro-organismos e acabam contaminando e inviabilizando os ambientes. Nos testes de biodegradação os substratos utilizados foram o naftaleno, o fenantreno e o diesel, juntamente com o indicador redox 2,6- diclorofenol-indofenol (DCPIP), que sofre descoloração (de azul para incolor) quando as células utilizam os substratos como fonte de carbono para o crescimento celular, gerando elétrons que vão reduzir o indicador. Pela análise do teste, 19 isolados degradaram o naftaleno, 16 degradaram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The genus Burkholderia comprises a very diverse group of bacteria occupying various ecological niches and has species that cause disease, but other species have important skills to the branches of agriculture, biotechnology and the environment, as biodegradation. These bacteria are morphologically similar genus and is divided into seventeen genomovars, where genetically similar species are grouped together, forming the Burkholderia cepacia complex (BCC). Through molecular studies of 16S rRNA and recA gene was possible to make the appropriate classification of species in 450 isolates of Terra Preta Antropogênica (TPA) and adjacent at four sites (TPA Caldeirão Cultivado; TPA Caldeirão Capoeira; TPA Hatahara e TPA Mina-I) were obtained 177 isolates of the genus Burkholderia. These isolates by 16S rRNA gene analysis was possible to classify 157 isolates to species level and the recA gene analysis only 105 isolates were classified in the same level. These isolates were used to test the biodegradation of hydrocarbons. Polyaromatic hydrocarbons (PAHs) are organic compounds resulting from incomplete combustion of organic matter and petroleum derivatives, are not very soluble in water and very toxic to cells, therefore, are not metabolized by many microorganisms to contaminate and render environments. In biodegradation tests the substrates used were naphthalene, phenanthrene and the diesel, along with the redox indicator 2,6- dichlorophenol-indophenol (DCPIP), who suffers discoloration (blue to colorless) when cells use the substrates as a source of carbon for cell growth, generating electrons that will reduce the indicator. By analysis of the test, 19 isolates degraded naphthalene, phenanthrene degraded the 16 and 126 degraded diesel, generating a total of 132 isolates of the genus Burkholderia that have the ability to degrade at least... (Complete abstract click eletronic access below) / Orientador: Dejanira de Franceschi de Angelis / Coorientador: Siu Mui Tsai / Banca: Margarete de Fátima Costa / Banca: Eleonora Cano Carmona / Mestre
4

Synthesis of Polyaromatic Hydrocarbons via Mechanochemistry

Wang, Cong 18 October 2019 (has links)
No description available.
5

Studium chemického složení atmosférických aerosolů / Study of chemical composition of atmospheric aerosols

Gazdošová, Lucie January 2008 (has links)
Atmospheric aerosols play an important role in various atmospheric issues (effect to the radiation budget of the atmosphere, visibility reduction, smog production, destruction of stratospheric ozone, …). Epidemiological studies proved a correlation between increased mortality and high concentration of ambient particulate matter. Over the past decade, a growing attention has been focused on the organic compounds that are constituents of aerosol particles. Although organic compounds comprise often up to 60% of the total aerosol mass, their composition, concentration and formation mechanisms are not well understood. Diploma thesis will deal with the study of chemical composition of organic compounds bound to atmospheric aerosols with focus on polyaromatic hydrocarbons and sugars. Atmospheric aerosols will be sampled on filters and filter extracts will be analysed for content of studied organic compounds by means of GC, GC-MS or LC, respectively. Development and optimalization of extraction methods (PSE, …) and detection of compounds of interest. Concentration of studied organic compounds in aerosol size fractions PM 10, PM 2.5 and PM 1 will be compared.
6

Residual Diesel Range Organics and Selected Frothers in Process Waters from Fine Coal Flotation

Morris, Joshua Powell 06 June 2013 (has links)
The purpose of this thesis is to examine some of the potential fates of processing reagents in a coal preparation plant.  The focus is specifically on petro-diesel (termed "diesel" in this paper), which is used as a collector in the flotation of fine coal.  Diesel range organics (DRO) and polyaromatic hydrocarbons (PAHs) are measured in aqueous samples using gas chromatography equipped with either a flame ionization detector (GC-FID) or a mass spectrometer (GC-MS).  Samples are subjected to a variety of test conditions in order to understand the behavior of diesel compounds in coal processing streams. Results show that frother and collector reagents are not likely to partition completely to a single fraction of the process slurry.  Further test work has shown that sub-ppm levels of DRO dominated by the water soluble fraction of diesel are expected to be present in process waters; however, PAHs and insoluble DRO may be removed via volatilization and/or degradation.  DRO and PAHs are also expected to be desorbed from coal particles when contacted with fresh water.  Flotation tests have revealed that low levels of DRO are found in both the concentrate and tailings processing streams with slightly higher concentrations being found in the concentrate stream.  From the tests performed in this thesis, it appears as though there is no apparent environmental concern when coal preparation plants are operating under normal conditions. / Master of Science
7

Graphenated polyaniline nanocomposite for the determination of polyaromatic hydrocarbons (pahs) in water

Tovide, Oluwakemi Omotunde January 2013 (has links)
Philosophiae Doctor - PhD / The thesis presents a simple, sensitive, low cost and a novel graphenated polyaniline doped tungsten trioxide nanocomposite, as an electrochemical sensor for the detection and quantitative and determination of PAHs, which are ubiquitous, toxic, as well as dangerous organic pollutant compounds in the environment. The selected PAHs (anthracene, phenanthrene and pyrene) in wastewater were given priority as a result of their threat to human nature and that of the environment. In order for a healthy, non-polluted and well sustainable environment, there is need for an instrument that is capable of detecting and quantifying these organic pollutants onsite and also for constant monitoring. The nanocomposites were developed by chemical and electrochemical methods of preparations, exploiting the intrinsic properties of polyaniline, graphene and tungsten trioxide semiconducting materials. Chemically, graphene-polyaniline (GR-PANI) nanocomposite was synthesised by in situ polymerisation method, then casted on a surface of glassy carbon electrode to form GR-PANI modified electrode. The properties of the prepared electrode were investigated through morphological and spectroscopic techniques, which confirmed the formation of the composite. The electroactivity of the prepared modified electrode revealed great improvement in cyclic and square wave voltammetric response on anthracene. A dynamic range of 2.0 × 10-5 to 1.0 × 10-3 M and detection limit of 4.39 x 10-7 M was established.
8

Biodegradação de naftaleno, fenantreno e diesel por isolados do gênero Burkholderia da Amazônia

Furlan, Bianca [UNESP] 29 March 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:27:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-03-29Bitstream added on 2014-06-13T18:31:32Z : No. of bitstreams: 1 furlan_b_me_rcla.pdf: 3556255 bytes, checksum: b8dadd1a50eb8caa4d6eb51e31dc8f1e (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O gênero Burkholderia compreende um grupo de bactérias muito diversificado, ocupando vários nichos ecológicos e possui espécies que causam doenças, mas outras espécies apresentam habilidades importantes para os ramos da agricultura, biotecnologia e do ambiente, como a biodegradação. Essas bactérias são morfologicamente semelhantes e o gênero está dividido em dezessete genomovars, onde espécies semelhantes geneticamente são agrupadas, formando o Complexo Burkholderia cepacia (CBC). Por meio de estudos moleculares do gene 16S rRNA e do gene recA foi possível fazer a classificação adequada em espécies dos 450 isolados obtidos da Terra Preta Antropogênica (TPA) e adjacentes, em quatro sítios (TPA Caldeirão Cultivado; TPA Caldeirão Capoeira; TPA Hatahara e TPA Mina-I), foram obtidos 177 isolados do gênero Burkholderia. Desses isolados, pela análise do gene 16S rRNA foi possível classificar 157 isolados ao nível de espécie e pela análise do gene recA somente 105 isolados foram classificados neste mesmo nível. Esses isolados foram utilizados no teste de biodegradação dos hidrocarbonetos. Os hidrocarbonetos poliaromáticos (HPAs) são compostos orgânicos resultantes da combustão incompleta da matéria orgânica e dos derivados de petróleo, são pouco solúveis em água e muito tóxicos para as células, por isso, não são metabolizados por muitos micro-organismos e acabam contaminando e inviabilizando os ambientes. Nos testes de biodegradação os substratos utilizados foram o naftaleno, o fenantreno e o diesel, juntamente com o indicador redox 2,6- diclorofenol-indofenol (DCPIP), que sofre descoloração (de azul para incolor) quando as células utilizam os substratos como fonte de carbono para o crescimento celular, gerando elétrons que vão reduzir o indicador. Pela análise do teste, 19 isolados degradaram o naftaleno, 16 degradaram... / The genus Burkholderia comprises a very diverse group of bacteria occupying various ecological niches and has species that cause disease, but other species have important skills to the branches of agriculture, biotechnology and the environment, as biodegradation. These bacteria are morphologically similar genus and is divided into seventeen genomovars, where genetically similar species are grouped together, forming the Burkholderia cepacia complex (BCC). Through molecular studies of 16S rRNA and recA gene was possible to make the appropriate classification of species in 450 isolates of Terra Preta Antropogênica (TPA) and adjacent at four sites (TPA Caldeirão Cultivado; TPA Caldeirão Capoeira; TPA Hatahara e TPA Mina-I) were obtained 177 isolates of the genus Burkholderia. These isolates by 16S rRNA gene analysis was possible to classify 157 isolates to species level and the recA gene analysis only 105 isolates were classified in the same level. These isolates were used to test the biodegradation of hydrocarbons. Polyaromatic hydrocarbons (PAHs) are organic compounds resulting from incomplete combustion of organic matter and petroleum derivatives, are not very soluble in water and very toxic to cells, therefore, are not metabolized by many microorganisms to contaminate and render environments. In biodegradation tests the substrates used were naphthalene, phenanthrene and the diesel, along with the redox indicator 2,6- dichlorophenol-indophenol (DCPIP), who suffers discoloration (blue to colorless) when cells use the substrates as a source of carbon for cell growth, generating electrons that will reduce the indicator. By analysis of the test, 19 isolates degraded naphthalene, phenanthrene degraded the 16 and 126 degraded diesel, generating a total of 132 isolates of the genus Burkholderia that have the ability to degrade at least... (Complete abstract click eletronic access below)
9

Avalia??o do processo oxidativo avan?ado por permanganato de pot?ssio no tratamento de solos contaminados com idrocarbonetos poliarom?ticos / Evaluation advanced oxidation Process by permanganate potassium in the Treatment of contaminated Soils with Polyaromatic Hydrocarbons

Silva, Celyna K?ritas Oliveira da 16 December 2010 (has links)
Made available in DSpace on 2014-12-17T15:01:24Z (GMT). No. of bitstreams: 1 CelynaKOS_DISSERT.pdf: 1291622 bytes, checksum: 6aba20d221ab35537c160d478e6ac5f7 (MD5) Previous issue date: 2010-12-16 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The soil contamination with petroleum is one of the major concern of industries operating in the field and also of environmental agencies. The petroleum consists mainly of alkanes and aromatic hydrocarbons. The most common examples of hydrocarbons polyaromatic are: naphthalene, anthracene, phenanthrene, benzopyrene and their various isomers. These substances cause adverse effects on human and the environment. Thus, the main objective of this work is to study the advanced oxidation process using the oxidant potassium permanganate (KMnO4) for remediation of soils contaminated with two polyaromatic hydrocarbons (PAHs): anthracene and phenanthrene. This study was conducted at bench scale, where the first stage was at batch experiment, using the variables: the time and oxidant dosage in the soil. The second stage was the remediation conducted in continous by a fix column, to this stage, the only variable was remediation time. The concentration of oxidant in this stage was based on the best result obtained in the tests at batch, 2,464 mg / L. The results of degradation these contaminants were satisfactory, at the following dosages and time: (a) 5g of oxidant per kg soil for 48 hours, it was obtained residual contaminants 28 mg phenanthrene and 1.25 mg anthracene per kg of soil and (b) for 7g of oxidant per kg soil in 48 hours remaining 24 mg phenanthrene and anthracene 0.77 mg per kg soil, and therefore below the intervention limit residential and industrial proposed by the State Company of Environmental Sao Paulo (CETESB) / A contamina??o de solo com petr?leo ? uma das grandes preocupa??es das ind?strias que atuam no ramo e tamb?m dos ?rg?os ambientais. O petr?leo ? constitu?do basicamente por hidrocarbonetos alcanos e arom?ticos. Os exemplos mais comuns dos hidrocarbonetos poliarom?ticos s?o: naftaleno, antraceno, fenantreno, benzopireno e seus v?rios is?meros. Estas subst?ncias apresentam efeitos nocivos ao ser humano e ao meio ambiente. Logo, este trabalho tem como principal objetivo, estudar o processo de oxida??o avan?ada, utilizando o oxidante permanganato de pot?ssio (KMnO4), na remedia??o de solos contaminados com dois hidrocarbonetos poliarom?ticos (HPAs): antraceno e fenantreno. Este estudo foi realizado em escala de bancada, sendo a primeira etapa realizada experimentos em batelada, utilizando as vari?veis: tempo de remedia??o e dosagem do oxidante. Na segunda etapa, a remedia??o foi realizada em regime cont?nuo utilizando coluna de leito fixo, para esta etapa a ?nica vari?vel foi tempo de remedia??o. A concentra??o do oxidante nesta etapa, foi baseada no melhor resultado obtido nos ensaios em batelada, 2464 mg/L. Os resultados da degrada??o destes contaminantes foram satisfat?rios, nas seguintes dosagens de oxidante e tempo de remedia??o: (a) 5g de oxidante por kg de solo em 48 horas, foram obtidos contaminantes residuais de 28 mg de fenantreno e 1,25 mg de antraceno por kg de solo e (b) para 7g de oxidante por kg de solo em 48 horas restaram 24 mg de fenantreno e 0,77 mg de antraceno por kg de solo, ficando abaixo dos valores de interven??o residencial e industrial propostos pela Companhia Ambiental do Estado de S?o Paulo (CETESB)
10

Field and Greenhouse Studies of Phytoremediation with California Native Plants for Soil Contaminated with Petroleum Hydrocarbons, PAHs, PCBs, Chlorinated Dioxins/Furans, and Heavy Metals

Poltorak, Matthew Robert 01 December 2014 (has links)
Native and naturalized California plant species were screened for their phytoremediation potential for the cleanup of soil contaminated with petroleum hydrocarbons (PHCs), poly-aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlorinated dioxins/furans, and heavy metals. This screening was followed by controlled greenhouse experiments to further evaluate the phytoremediation potential of the best candidates. Field specimens and soils used for this study were collected from the former Energy Technology Engineering Center (ETEC) at the Santa Susana Field Laboratory in Southern California that was operated by the Department of Energy (DOE). Soils at this site contain all of the contaminants of interest (COIs). Nine plant species were screened in the field: Purple Needlegrass (Nassella pulchra), Blue Elderberry (Sambucus nigra), Laurel Sumac (Malosma laurina), Mule Fat (Baccharis salicifolia), Palmer’s Goldenbush (Ericameria palmeri), Summer Mustard (Hirschfeldia incana), Narrowleaf Milkweed (Asclepias fascicularis), Coyote Brush (Baccharis pilularis), and Thickleaf Yerba Santa (Eriodictyon crassifolium). In the field three samples of each species growing in contaminated soil and one of each species growing in uncontaminated soil were selected for harvesting and analysis. The roots, above ground plant tissue, and soil around the roots were sampled separately and analyzed for the COIs: PHCs, PAHs, PCBs, chlorinated dioxins/furans, and metals (which include mercury, silver, cadmium, and lead). All of the plants in the field appeared to generate compounds which result in higher measured PHC concentrations than those measured in the associated soil. The highest concentrations of PAHs in the roots were observed for Blue Elderberry (1740 ug/kg), Purple Needlegrass (703 ug/kg), and Yerba Santa (200 ug/kg). No uptake of PCBs was observed in the roots or foliage of any species. The highest concentrations of total chlorinated dioxins/furans in the roots were observed for Purple Needlegrass (2237 ng/kg), Blue Elderberry (1026 ng/kg), Palmer’s Goldenbush (432 ng/kg), and Yerba Santa (421 ng/kg). The highest concentrations of total chlorinated dioxins/furans in the foliage were observed for Yerba Santa (901 ng/kg), Palmer’s Goldenbush (757 ng/kg), and Purple Needlegrass (694 ng/kg). No uptake of mercury was observed in the roots or foliage of any species. The highest concentration of silver in the roots was observed for Laurel Sumac (7.34 mg/kg). Summer Mustard (SM) was the only species that showed uptake of silver into the foliage (0.405 mg/kg). The highest concentrations of cadmium in the roots and foliage were observed for Mule Fat (1.84 mg/kg and 3.64 mg/kg) and Coyote Brush (1.52 mg/kg and 2.12 mg/kg) and the greatest concentration of lead in the roots and foliage was observed for Purple Needlegrass (8.92 mg/kg and 1.17 mg/kg). Plants with a wide variety of observed contaminant uptake in the field were selected for a second phase of research in which three of the most promising species were grown in greenhouse microcosms to quantify the removal of contaminants from the soil. The three species selected based on preliminary results from the field study were Coyote Brush, Mule Fat, and Purple Needlegrass. Microcosms consisted of 2.17 kg of soil in 4-L glass jars with glass marbles for an underdrain. Plants were watered with deionized water and no leachate was collected. Five replicates of each microcosm type were created and incubated for 211 days with soil sampling at 85 and 211 days. Soil, plant roots/above ground tissue, and volatilization from the plants were analyzed for COIs to determine the mechanisms of phytoremediation. One set of microcosms was used to test the effect of addition of achelating agent (ethylenediaminetetraacetic acid) and another set was used to test the effect of fertilizer addition on phytoremediation potential. Three control treatments were tested: sterilized (gamma irradiation) soil planted with Purple Needlegrass, unplanted soil, and sterilized unplanted soil. None of the plant species demonstrated volatilization of COIs under these conditions. Volatilization of mercury was not tested for. The average PCB concentration (measured as Aroclor 1260) reductions in soils with Purple Needlegrass and chelated Coyote Brush were 49.4% and 51.4% respectively (p < 0.05). However, the sterilized unplanted control also had a decrease of Aroclor 1260 concentrations in the soil of 36.6% (p < 0.05). None of the species phytoextracted PCBs, so the mechanism of PCB remediation appears to be phytostimulation of the rhizosphere. Purple Needlegrass showed the greatest uptake of dioxins/furans into the foliage but did not appear to reduce the dioxin/furan concentrations in the soil. Coyote Brush, fertilized Coyote Brush, and Mule Fat also showed uptake of dioxins/furans into the roots and foliage. Only the Coyote Brush and fertilized Coyote Brush significantly (p = 0.036, p = 0.022) reduced the total dioxin/furan concentration in the soil (17.8% and 19.8% respectively). Coyote Brush may have stimulated microbes in the rhizosphere to better degrade the dioxins/furans. None of the plants were identified as hyper-accumulators of metals, and none of the soil metal concentrations significantly decreased in any of the microcosms. All of the metals (except mercury) were taken into the roots of plants to some degree, with Purple Needlegrass showing the most promise for metal extraction as it showed some of the highest concentrations of metals in roots and was the only species that contained mercury and silver in the foliage. This study suggests that there is some potential for phytoremediation of PCBs and chlorinated dioxins/furans. The results for petroleum hydrocarbons were inconclusive. Metal uptake was not substantial enough to lower metal concentrations in the soils. Thus phytoremediation of COIs at the site is limited and more aggressive forms of remediation may be required to reduce the concentrations of COIs quickly.

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