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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.
341

Biodegradation of polycyclic aromatic hydrocarbon contaminants in a mixed culture bioreactor

Amodu, Olusola S January 2015 (has links)
Thesis submitted in fulfilment of the requirements for the degree of Doctor Technologiae: Chemical Engineering, Faculty of Engineering at the Cape Peninsula University of Technology - Cape Town, South Africa / Polycyclic aromatic hydrocarbons (PAHs) are one of the most common and recalcitrant environmental contaminants – known for their potential toxicity, mutagenicity, and carcinogenicity to humans. Biosurfactant application can enhance the biodegradation of PAHs. The main object of this work was to explore the novelty of biosurfactant produced by the isolated strains of Bacillus sp and Pseudomonas aeruginosa grown exclusively on Beta vulgaris, and the modification of the zeolites nanoparticles by the biosurfactant, for enhanced biodegradation of PAHs in soil. Novel biosurfactant-producing strains were isolated from hydrocarbon-contaminated environments, while several agrowaste were screened as primary carbon sources for the expression of biosurfactants, which were quantified using various standardized methods......
342

Análise do monitoramento ambiental e da delimitação das plumas de contaminantes provenientes de vazamentos em postos de combustíveis: estudos de caso no médio Vale do Paraíba

Santos, Dione Aline Ribeiro dos [UNESP] 07 July 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-07-07Bitstream added on 2014-06-13T19:39:51Z : No. of bitstreams: 1 santos_dar_me_guara.pdf: 2671476 bytes, checksum: e5d331115c49706ae96e28db4c572039 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As contaminações do solo e de águas subterrâneas por vazamentos em postos de combustíveis têm sido alvo de inúmeras pesquisas, devido à complexidade dos fenômenos de interação com o solo e o grande número de contaminações. Entre as dificuldades para a proteção ambiental estão as avaliações da extensão, da dinâmica e da concentração das contaminações provocadas por estes vazamentos, oriundas das deficiências de infra-estrutura, manutenção e desgastes nas instalações e a falta de fiscalização de tanques e equipamentos. Entender a dinâmica dos hidrocarbonetos derivados de petróleo, gasolina e óleo diesel, e seu comportamento em solo, é um passo importante no esforço para o entendimento da migração e transporte destes contaminantes para as águas subterrâneas. Esta dissertação apresentou uma análise das plumas de contaminação e dos procedimentos adotados para a delimitação das mesmas. Para tanto, foram analisados dois estudos de caso de vazamentos de postos de combustíveis na região do Médio Vale do Paraíba. / The contaminations of the soil and of groundwaters for leaks in put of fuels have been objective of countless researches due to complexity of the interaction phenomena with the soil and the great number of contaminations. One of the difficulties in the activities gone back to the environmental protection it consists of the evaluation of the extension, dynamics and concentration of the contaminations provoked by these leaks, originating from of the infrastructure deficiencies, maintenance and wastes in the facilities, as well as lack of fiscalization of tanks and equipments. To understand the dynamics of the derived of petroleum hydrocarbon, gasoline and diesel oil, and your behavior in soil, it is an important step in the effort for the understanding of the migration and transport of these pollutants in the groundwater. The dissertation presented an analysis of the feathers of contamination and of the procedure for limitation of the same ones. For so much, two studies of case of leaks of positions of fuels were analyzed in the area of the Medium Valley of Paraíba.
343

Validação do uso de n-alcanos como indicadores para estudos nutricionais em veados - catingueiro (Mazama gouazoubira). / Validation of the use of n-alkanes as markers for nutritional trials with grey brocket deer (Mazama gouazoubira).

Juliano Barbosa 30 January 2004 (has links)
Determinações do consumo e da digestibilidade, atravé s do método de coleta total de fezes, foram realizadas em 8 veados–catingueiros (Mazama gouazoubira) recebendo uma dieta peletizada composta por 63,9% de feno de alfafa, 16,9% de amido de milho, 14,7% de levedura (Saccharomyces cerevisiae), 2,5% de melaço, 1,5% de um premix vitamínico-mineral e 0,5% de cloreto de sódio em base seca. As estimativas dos coeficientes de digestibilidade foram determinadas paralelamente através do uso de indicador fecal (n-alcanos) com o intuito de validar a metodologia para esses pequenos ruminantes. O consumo médio de matéria seca e água durante o período de coleta foram: 24g ± 2,5 e 67 mL ± 11,5 por quilo de peso vivo (PV), sendo que os animais não apresentaram perdas de peso durante o período experimental. Quando expresso em peso metabólico (PV0,75), os animais consumiram em média 48g ± 5,2 de matéria seca e 136,4 mL ± 23,8 de água. O consumo de energia digestível foi em média 1.089 kcal/dia. As médias dos coeficientes de digestibilidade aparente obtidas através da coleta total de fezes, foram de 61,6% ± 1,7 para matéria seca, 63,9% ± 1,6 matéria orgânica, 69,7% ± 3,4 nitrogênio, 31,7% ± 3,7 fibra em detergente neutro, 45,2 ± 2,4 celulose e 18,8 ± 5,6 para a lignina. Os coeficientes de digestibilidade estimados para as diferentes frações através da utilização dos n-alcanos C31 e C33 se mostraram precisos e acurados em relação aos coeficientes de digestibilidade observados por coleta total quando as recuperações fecais foram incluídas nos cálculos de digestibilidade (P>0,05). Consistente com valores obtidos em ovinos, as recuperações fecais dos n-alcanos de cadeia ímpares aumentaram com o aumento do número de carbonos da cadeia de hidrocarboneto sendo que estes valores poderão ser utilizados em futuros estudos onde se deseja determinar a composição botânica da dieta dos cervídeos. / Feed intake and digestibility estimates were determined by the total fecal collection method of 8 deer (Mazama gouazoubira) receiving a pelleted diet of 63.9% alfalfa hay, 16.9% corn starch, 14.7% yeast (Saccharomyces cerevisiae), 2.5% mollasses, 1.5% mineral-vitamin mix, and 0.5% NaCl on DM basis. n-alkane tracer method was used in parallel with total fecal collection to validate its application on wild small ruminants. The mean DM feed intake and water intake during the collection period were 24g ± 2.5 and 67 mL ± 11.5 per kg BW, and the animals did not present weight losses during the experimental period. When these values were expressed on kg of metabolic live weight, the animals consumed 48g ± 5.2 of DM and 136.4 mL ± 23.8 of water. Digestible energy intake was estimated at 1,089 kcal/day. The mean coefficients of apparent digestibility observed by total fecal collection for dry matter was 61.6% ± 1.7; organic matter 63.9% ± 1.6, nitrogen 69.7 % ± 3.4, neutral detergent fiber 31.7% ± 3.7, cellulose 45.2 % ± 2.4, and lignin 18.8% ± 5.6. The digestibility coefficients estimated for the different fractions by the n-alkanes C31 and C33 were accurate when compared to those observed by the total fecal collection method when feces recovery was included on digestibility calculations (P>0.05). Consistent with values obtained in sheep, the fecal recoveries of the odd chain n-alkanes was greater with the increase of the number of carbons of the chain of hydrocarbon and these values can be used in future studies to determine the botanical composition of the deer’s diet.
344

Metodologia geofísica para contaminação por hidrocarbonetos - estudo de caso em posto de combustíveis / Geophysical methods to hydrocarbon contamination - case history in service station

Silvia Guimarães Marques 27 August 2007 (has links)
A água subterrânea abastece grande parte da população e sua contaminação é assunto de interesse público. Os postos de combustíveis são fontes potenciais de contaminação, devido à sua extensa malha de distribuição e pelo armazenamento de produto ser predominantemente subterrâneo. Dentre os métodos para detecção de hidrocarbonetos, os geofísicos proporcionam investigação em maiores extensões, com mais rapidez e menor custo. Este estudo apresenta os resultados de quatro métodos geofísicos (eletrorresistividade, polarização induzida, georradar e eletromagnético EM-34) na investigação de dois perfis a jusante de um posto de combustível com histórico de vazamento. Os objetivos foram de detectar a pluma de contaminação e identificar qual dos métodos apresenta os melhores resultados nesta situação. A eletrorresistividade apresentou a melhor correlação com a zona contaminada e com as análises químicas. Os dados da polarização induzida também se relacionaram com a pluma. Os valores do sistema EM-34 ficaram aquém das expectativas. Os do georradar não possibilitaram nenhuma correlação com o substrato contaminado, certamente devido a pouca profundidade de penetração. Foi constatado que a contaminação por hidrocarbonetos não oferece assinatura geoelétrica previsível, devido às condições dinâmicas do campo e suas inter-relações. Enquanto muitos trabalhos associam baixas resistividades aos vazamentos antigos, outros trabalhos mostram o inverso. Neste estudo, a anomalia encontrada apresentou alta resistividade associada às cargabilidades mais altas. / A large portion of the population is supplied with groundwater, and this is a matter of public interest. Gas stations are potential sources of contamination for its extensive distribution network and for the underground storage. Among the existing methods for hydrocarbon detection, the geophysical ones provide a larger range, faster results at smaller costs. This work presents the results of four geophysical methods (electrical resistivity, induced polarization, ground penetrating radar and electromagnetic EM-34) applied to the study of two profiles downwards of a leaking gas station. The objectives were detecting the contamination plume and identify which of the methods employed presents the best results on this site. The electrical resistivity method presented the best correlation with the contaminated zone and chemical analysis. The results of the induced polarization were also associated with the contamination plume. Values obtained with the EM-34 didn?t fulfill the expectations. GPR data didn?t correlate with the contaminated substrate, certainly due to the shallow penetration depth. It was observed that the hydrocarbon contamination does not offer a predictable geoelectrical signature, due to the dynamic conditions of the field and its inter relations. Whilst several paper associate low resistivities to older leakages, in other papers it was found the opposite. In this case study, the anomaly has shown characteristics of high resistivity associated to higher chargeabilities.
345

Caracterização de Fontes e Distribuição de Matéria OrgÂnica no Sedimento do Estuário do Capibaribe (PERNAMBUCO, BRASIL) através de Marcadores Elementares, Isotópicos e Moleculares

RESENDE, Jéssica Sonaly da Silva 27 September 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-07-21T14:29:51Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO - RESENDE 2015.pdf: 1812905 bytes, checksum: a279042ee00914f24aa6181c3e1baafe (MD5) / Made available in DSpace on 2016-07-21T14:29:51Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO - RESENDE 2015.pdf: 1812905 bytes, checksum: a279042ee00914f24aa6181c3e1baafe (MD5) Previous issue date: 2015-09-27 / CNPq / Os estuários são ambientes importantes tanto do ponto de vista ecológico quanto econômico, estando frequentemente sob ação antrópica. A matéria orgânica (MO) depositada no sedimento estuarino pode ser de origem alóctone ou autóctone. O objetivo deste trabalho foi investigar a origem e a distribuição da MO no sedimento coletado no estuário do Rio Capibaribe (Recife – PE). Para tanto foram empregados marcadores geoquímicos elementares, isotópicos e moleculares. As amostras de sedimento foram coletadas em 18 estações ao longo do canal principal do estuário do Rio Capibaribe. Os resultados da análise granulométrica mostraram que houve predominância da fração lamosa no sedimento do estuário. A composição elementar mostrou que mais da metade das estações apresentaram predomínio de mistura de fontes marinha e terrestre. O percentual médio de carbono e nitrogênio reportados neste estudo apresentaram valores acima dos encontrados em estudos feitos em outros ambientes impactados. Os valores de δ13C ao longo do estuário apresentaram média de -24,45‰, com mais da metade deles dentro da faixa tipicamente encontrada em fontes de origem continental (oriunda de plantas C3). O valor médio de δ15N foi 8,34‰, indicando uma mistura de fontes com contribuição de efluentes. A concentração de hidrocarbonetos alifáticos (HAs) totais nas amostras de sedimento apresentou mediana de 178,89 μg g-1 peso seco, indicando que o estuário em questão se encontra contaminado por petróleo e seus derivados. As concentrações de hidrocarbonetos policíclicos aromáticos (HPAs) totais apresentaram mediana de 424,83 ng g-1 peso seco, indicando contaminação moderada desses compostos no sedimento do estuário, que são oriundos principalmente de fontes pirolíticas. Os resultados obtidos permitem deduzir que o ambiente estuarino do Rio Capibaribe está impactado pela ação antrópica e sua MO sedimentar recebe contribuições de fontes mistas oriunda de fontes marinhas e terrestres, incluindo descarga de esgotos. Além disso, há contaminação moderada de HAs e HPAs, respectivamente. Este último grupo é reconhecidamente tóxico para organismos e os níveis de diversos HPAs no sedimento do Capibaribe estão acima daqueles permitidos para sedimentos sujeitos a operações de dragagem (segundo a resolução 454/2012 do Conselho Nacional do Meio Ambiente). / Estuaries are key environments that are often under anthropogenic pressure. Organic matter (OM) of estuarine sediments may be from either allochthonous or autochthonous sources. This study investigated sources and fate of OM in sediments from the Capibaribe estuary (Recife, northeastern Brazil). Eighteen samples were collected along the main channel of the estuary. Analyses of grain size, elemental composition, stable isotopes and hydrocarbons were carried out in the samples. Grain size analysis showed that sediments are mainly comprised of mud (i.e., silt and clay particles). In over half of the samples, organic carbon and total nitrogen percentages evidenced a mixture of marine and terrigenous sources. The average percent composition of organic carbon and total nitrogen in the Capibaribe estuary is higher than in other impacted areas. The δ13C values in sediment averaged -24,45‰, with more than half of samples ranging within the C3 plants isotopic signature. The average δ15N value was 8,34‰, suggesting high input of anthropogenic effluents. Total concentration of aliphatic hydrocarbons (AHs) in sediment samples exhibited a median value of 178,89 μg g-1 dry weight, indicating moderate petroleum contamination. Total concentration of polycyclic aromatic hydrocarbons (PAHs) exhibited a median value of 424,83 ng g-1 dry weight. These levels indicate a moderate input of PAHs to the estuary. The data sets evidenced that the Capibaribe estuary is under significant anthropogenic pressure. The sedimentary OM is comprised of several sources, including sewage. PAHs are acknowledged to be toxic for organisms and some of them were detected in estuarine sediments at levels above those permitted by Brazilian regulations.
346

[en] DIRECT SYNTHESIS OF HYDROCARBONS FROM SYNTHESIS GAS OVER HYBRID CATALYSTS BASED ON HFERRIERITE ZEOLITE / [pt] SÍNTESE DIRETA DE HIDROCARBONETOS A PARTIR DO GÁS DE SÍNTESE SOBRE CATALISADORES HÍBRIDOS BASEADOS EM ZEÓLITA H-FERRIERITA

JHONNY OSWALDO HUERTAS FLORES 12 November 2008 (has links)
[pt] Existe uma crise energética devido ao excessivo consumo do petróleo e à contaminação em suas diversas formas. Há enormes reservas de gás natural e a conversão deste gás em combustíveis líquidos a partir do gás de síntese, que vem do gás natural, via metanol, e posterior transformação do metanol em hidrocarbonetos é uma interessante alternativa. Catalisadores híbridos formados por um catalisador de síntese de metanol e um material ácido poroso, geralmente uma zeólita, são empregados para esta síntese direta. Seis famílias de catalisadores híbridos foram sintetizadas onde diversas variáveis foram testadas como: método de preparação do catalisador híbrido, método de preparação do catalisador de síntese de metanol, fase ativa, razão catalisador de síntese de metanol/zeólita, acidez da zeólita e diferente promotor. A zeólita empregada em todos os sistemas foi a H-ferrierita. O método de preparação influenciou nas propriedades estruturais, texturais, morfológicas, ácidas e catalíticas do catalisador híbrido. O melhor método de preparação do catalisador híbrido foi o método de coprecipitação-sedimentação que se mostrou mais ativo em temperaturas acima de 300°C. Observaram-se diferenças morfológicas nas partículas do catalisador de síntese de metanol (CSM) quando diferentes métodos de preparação foram empregados. O cobre, entre as fases ativas, mostrou-se a melhor na síntese direta de hidrocarbonetos a partir do gás de síntese em temperaturas acima de 300°C. A melhor razão catalisador de síntese de metanol/zeólita, nesta síntese direta, foi de 2:1. O cromo no sistema Cu-Zn-Al favoreceu a atividade em 250°C. Baixas razões acidez total/área de Cu(0) e altas temperaturas (350 e 400°C) favoreceram maiores conversões e seletividades em propano e butano, baixas temperaturas (300°C) favoreceram a formação de DME. Altas razões acidez total/área de Cu(0) favoreceram a formação de etano. A distribuição dos produtos na síntese direta de hidrocarbonetos a partir do gás de síntese foi dependente da temperatura de reação. Éter dimetílico apresentou um máximo em 300ºC. A síntese do metanol, parece ser a etapa limitante do processo. / [en] An energy crisis due to the extreme consumption of the oil and to the contamination in its diverse forms exists. There are enormous natural gas reserves and the conversion of this gas in liquid fuels from the synthesis gas, through methanol, and posterior transformation of methanol in hydrocarbons is an interesting alternative. Hybrid catalysts based in methanol synthesis catalyst and an acidic porous material such as zeolites, are used for this direct synthesis. Six groups of hybrid catalyst were prepared and several properties studied such: preparation method of the hybrid catalyst, preparation method of the methanol synthesis catalyst, active site, CuO-ZnO-Al(2)O(3)/H- ferrierite ratio, acidity of the zeolite and different promoter. The zeolite used in all the systems was the ferrierite. The preparation method influenced the structural, textural, morphologic, acid and catalytic properties of the hybrid catalyst. The coprecipitationsedimentation method was more active in temperatures above 300°C. Morphologic differences in particles of the catalyst of methanol synthesis were observed when different preparation methods were used. The copper as active site was the better in the direct synthesis of hydrocarbons from synthesis gas in temperatures above 300°C. The best CuO-ZnO-Al(2)O(3)/H- ferrierite catalyst ratio, in this direct synthesis, was 2:1. The chromium in the Cu-Zn- Al system favored the activity in 250°C. Low acidity/metallic area Cu(0) ratio and high temperatures (350 and 400°C) favored higher activities and selectivities in propane and butane, lower temperatures (300°C) favored the DME formation. High acidity/metallic area Cu(0) ratio favored the formation of ethane. The hydrocarbons distribution was dependent on the reaction temperature. Dimethyl ether showed a maximum at 300°C. The methanol, seens to be the limitant step of the process.
347

Etude de la résistance cuticulaire chez Anopheles gambiae / Study of cuticular resistance in Anopheles gambiae

Yahouedo, A. Gildas 04 July 2017 (has links)
La gestion de la résistance aux insecticides et plus particulièrement aux pyréthrinoïdes chez les vecteurs du paludisme est un enjeu majeur pour conserver les acquis de la lutte antivectorielle contre le paludisme. Parmi les mécanismes de résistance, de nombreux travaux ont porté sur les mutations de la cible insecticides (kdr) ou encore les enzymes qui métabolisent les molécules insecticides. La résistance cuticulaire chez Anopheles gambiae a jusqu'à ce jour au mieux été suspectée mais pas démontrée. Dans ce cadre, le but de ce travail était donc de déterminer i) s’il y a une implication de la cuticule dans le phénotype résistant d’Anopheles gambiae aux pyréthrinoïdes ; ii) de déterminer les principaux acteurs de cette résistance. Nous avons construit une souche d’Anopheles gambiae présentant un phénotype résistant (MRS) mais ne portant pas la mutation kdr. Notre approche a été d’étudier l’expression des gènes, mais aussi celle des protéines de la cuticule et celles intervenant dans la détoxication. L’ultrastructure de la cuticule, sa composition en chaines hydrocarbonées ainsi que sa perméabilité à la deltaméthrine ont aussi été testés. Nous avons montré que la cuticule est impliquée dans le phénotype résistant plus particulièrement en réduisant significativement la pénétration de la deltaméthrine dans le corps de l’insecte. La structure même de la cuticule est profondément modifiée chez MRS. Nos résultats indiquent l’implication des membres de la famille CPAP3 dans la résistance cuticulaire et probablement des chaines hydrocarbonées. Des enzymes métaboliques sont également impliqués. Au cours de ce travail, nous avons démontré l’existence de la résistance cuticulaire chez An.gambiae, ce mécanisme agit de concert avec les mécanismes de détoxication. La caractérisation des différents acteurs nous permettra surement de trouver de nouvelles cibles pour la lutte anti-vectorielle.Mots clés : Résistance, cuticule, An.gambiae, deltaméthrine, ultrastructure, perméabilité, protéines / The management of Anopheles insecticide resistance, especially to pyrethroids, is a key challenge to preserve success of vector control against malaria. Among resistance mechanisms target site mutation (kdr) and metabolic resistance are well known. Cuticular resistance in malaria vectors has been overlooked, just suggested but not established so far. The aim of this PhD work was to demonstrate i) the involvement of cuticle in pyrethroid resistance in An. gambiae; ii) to determine which components act on this mechanism. To achieve this, we built An.gambiae strain resistant to pyrethroids and free of kdr mutation (MRS). We studied both cuticular and metabolic genes and proteins expressions by transcriptomic and proteomic approaches. Cuticle ultrastructure and biochemical composition were also investigated. At least, cuticle permeability to deltamethrin was also assessed. Our results showed that cuticle is involved in resistant phenotype in An.gambiae. MRS cuticle reduces insecticide uptake in the mosquito’s body linked to an increasing cuticle thickness in MRS. Expression and chemical studies revealed that CPAP3 family and epicuticular hydrocarbons takes part in this process. This work also suggested that metabolic enzymes act together with cuticular mechanism to resistant phenotype. How the different components interacts could improve our knowledge of resistance and bring new target for vector control.Keywords: Resistance, cuticle, An.gambiae, deltamethrin, ultrastructure, permeability, proteins
348

Quantifying the Toxicity of 1-Methylnaphthalene to the Shallow-Water Coral, Porites divaricata, for Use in the Target Lipid Model

Turner, Nicholas 02 September 2016 (has links)
The proximity of coral reefs to coastal urban areas and shipping lanes predisposes corals to petroleum pollution from multiple sources. Previous research has evaluated petroleum toxicity to coral using a variety of methodologies, including monitoring effects of acute and chronic spills, in situ exposures, and ex situ exposures with both adult and larval stage corals. Variability in toxicant, bioassay conditions, species and other methodological disparities among studies prevents comprehensive conclusions regarding the toxicity of hydrocarbons to corals. This research evaluated the 48-hour toxicity of 1-methylnaphthalene to Porites divaricata using a continuous-flow passive dosing system. The range-finding exposure evaluated the dosing protocol and verified the effectiveness of the passive dosing technique at maintaining exposure concentrations. The full-toxicity exposures resulted in a precise estimate of toxic threshold concentrations for use in the target lipid model. The target lipid model promoted comparisons across different species by calculating the critical target lipid body burden of 355.7 µmol/ g lipid for P. divaricata. This indicates a greater resilience to petroleum hydrocarbon exposure compared to other species for which these data are available.
349

Levels of Polycyclic Aromatic Hydrocarbons Archived Subcutaneous Blubber Samples in the Florida Manatee (Trichechus manatus latirostris)

Bigelow, Melinda Michelle 01 August 2006 (has links)
Polycyclic aromatic hydrocarbons (PAH) have been linked to cancer in humans. Subsequently, 16 of them were listed as priority pollutants by the Environmental Protection Agency in the Clean Water Act. The Florida manatee (Trichechus manatus latirostris) is an herbivorous endangered species that could have the potential to accumulate these compounds. The waters they inhabit have been shown to have PAH concentrations in the sediment from 0.035 μg/g w.w. (wet weight) to 0.686 μg/g w.w. PAH bioaccumulate due to their lipophilic nature and the manatee has a thick blubber layer that may allow for the accumulation of these compounds. Forty-eight archived subcutaneous manatee blubber samples were collected from Florida Fish and Wildlife Conservation Commission Marine Mammal Pathobiology lab and analyzed for 16 known priority pollutant PAH. Samples were then compared to a standard using HPLC analysis. Concentrations were found to range from 0.001 μg/g w.w. to 84.84 μg/g w.w. All 16 priority pollutant PAH were found, however not all 16 were found in any one animal. Forty-six of forty-eight manatee samples analyzed were found to have at least one form of PAH. The number of occurrences of each PAH out of 48 samples ranged from 1-19. The highest average PAH concentration was acenaphthylene with 12.60 μg/g w.w. There was no significant difference (p-value >0.10) between total, carcinogenic and noncarcinogenic PAH, with levels of 2.01 μg/g w.w., 2.18 μg/g w.w. and 1.84 μg/g w.w. respectively. No significant difference (p-value >0.10) was found between year or location of carcass recovery as well as sex of manatee. Averages ranged between 0.02 μg/g w.w. and 18.92 μg/g w.w. for year and 0.15 μg/g w.w. and 5.68 μg/g w.w. for location. Male average levels were 5.21 μg/g w.w., while female averages and perinatal averages were 1.51 μg/g w.w. and 1.147 μg/g w.w. respectively.
350

Flaring and pollution detection in the Niger Delta using remote sensing

Morakinyo, Barnabas Ojo January 2015 (has links)
Through the Global Gas Flaring Reduction (GGFR) initiative a substantial amount of effort and international attention has been focused on the reduction of gas flaring since 2002 (Elvidge et al., 2009). Nigeria is rated as the second country in the world for gas flaring, after Russia. In an attempt to reduce and eliminate gas flaring the federal government of Nigeria has implemented a number of gas flaring reduction projects, but poor governmental regulatory policies have been mostly unsuccessful in phasing it out. This study examines the effects of pollution from gas flaring using multiple satellite based sensors (Landsat 5 TM and Landsat 7 ETM+) with a focus on vegetation health in the Niger Delta. Over 131 flaring sites in all 9 states (Abia, Akwa Ibom, Bayelsa, Cross Rivers, Delta, Edo, Imo, Ondo and Rivers) of the Niger Delta region have been identified, out of which 11 sites in Rivers State were examined using a case study approach. Land Surface Temperature data were derived using a novel procedure drawing in visible band information to mask out clouds and identify appropriate emissivity values for different land cover types. In 2503 out of 3001 Landsat subscenes analysed, Land Surface Temperature was elevated by at least 1 ℃ within 450 m of the flare. The results from fieldwork, carried out at the Eleme Refinery II Petroleum Company and Onne Flow Station, are compared to the Landsat 5 TM and Landsat 7 ETM+ data. Results indicate that Landsat data can detect gas flares and their associated pollution on vegetation health with acceptable accuracy for both Land Surface Temperature (range: 0.120 to 1.907 K) and Normalized Differential Vegetation Index (sd ± 0.004). Available environmental factors such as size of facility, height of stack, and time were considered. Finally, the assessment of the impact of pollution on a time series analysis (1984 to 2013) of vegetation health shows a decrease in NDVI annually within 120 m from the flare and that the spatio-temporal variability of NDVI for each site is influenced by local factors. This research demonstrated that only 5 % of the variability in δLST and only 12 % of the variability in δNDVI, with distance from the flare stack, could be accounted for by the available variables considered in this study. This suggests that other missing factors (the gas flaring volume and vegetation speciation) play a significant role in the variability in δLST and δNDVI respectively.

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