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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

Desenvolvimento de novos comp?sitos de biopl?stico e ze?lita/TiO2/TiO2-Fe+3 para remo??o de poluentes ambientais / Development new composites of bioplastics and zeolite/TiO2/TiO2-Fe+3 for the removal of environmental pollutants

Cardoso, Ariela Milbrath 29 August 2016 (has links)
Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-11-17T17:04:10Z No. of bitstreams: 1 TES_ARIELA_MILBRATH_CARDOSO_COMPLETO.pdf: 5243886 bytes, checksum: f7d5c5963bb3a8537909fa88fd5d1e20 (MD5) / Made available in DSpace on 2016-11-17T17:04:10Z (GMT). No. of bitstreams: 1 TES_ARIELA_MILBRATH_CARDOSO_COMPLETO.pdf: 5243886 bytes, checksum: f7d5c5963bb3a8537909fa88fd5d1e20 (MD5) Previous issue date: 2016-08-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / The development of new composite materials with adsorption capacity and photodegradation become an increasing need for environmental pollution control. This thesis describes the development of composite type zeolite /TiO2/TiO2-Fe+3 and bioplastic composites, for use in the photodegradation of methylene blue and adsorption with n-butanol vapor photodegradation. The synthesis of composite type zeolite/TiO2/TiO2-Fe+3 was carried out by two distinct routes: mechanical mixing and sol-gel. For the synthesis of bioplastic composite was used biopolymer polylactic acid (PLA) via the solvent evaporation technique. The materials were characterized by various techniques: XRD, FEG-SEM-EDS, TEM, NMR, FTIR, TGA, DSC, N2 physisorption, SAXS, Raman. FEG-SEM results and NMR composite type zeolite/TiO2/TiO2-Fe+3 indicate a small dealuminization of zeolite, and high degree of coverage of the surface by nanoparticle TiO2/TiO2-Fe+3 through the synthesis method sol-gel. The photodegradation of methylene blue by composite zeolite/TiO2/TiO2-Fe+3 was more than 95% in ultraviolet radiation, ion doping with Fe+3 semiconductor allowed activation with visible radiation. The bioplastic composites had lower crystallinity degree of the pure PLA. Equilibrium adsorption of n-butanol (Ci = 3500 ppmv, odor level 5) in the bioplastic composite was achieved between 40-50 min for all samples tested, with a removal percentage of between 54-72%. The photodegradation with visible radiation was observed after 45 min illumination system, the formation of CO, CO2 and short chain oxygenates was confirmed by gas chromatography. These results suggest that the compounds synthesized in this work have potential applications for the tested. / O desenvolvimento de novos materiais comp?sitos com capacidade de adsor??o e fotodegrada??o se torna uma necessidade cada vez maior para o controle da polui??o ambiental. Este trabalho relata o desenvolvimento de comp?sitos do tipo ze?lita/TiO2/TiO2-Fe+3 e comp?sitos de biopl?stico, para aplica??o em fotodegrada??o de azul de metileno e adsor??o/fotodegrada??o de vapor de n-butanol. A s?ntese dos comp?sitos ze?lita/TiO2/TiO2-Fe+3 foi realizada por duas rotas distintas: mistura mec?nica e sol-gel. Para a s?ntese dos comp?sitos de biopl?stico foi utilizado o biopol?mero poli ?cido l?ctico (PLA) via t?cnica de evapora??o de solvente. Os materiais foram caracterizados atrav?s de diversas t?cnicas: DRX, FEG-MEV-EDS, MET, RMN, FTIR, TGA, DSC, Fisissor??o de N2, SAXS, Raman. Resultados de FEG-MEV e RMN dos comp?sitos ze?lita/TiO2/TiO2-Fe+3 indicam uma pequena desaluminiza??o da ze?lita, e alto grau de recobrimento de sua superf?cie pelas nanopart?culas de TiO2/TiO2-Fe+3 atrav?s do m?todo de s?ntese sol-gel. A fotodegrada??o do azul de metileno obtida pelos comp?sitos ze?lita/TiO2/TiO2-Fe+3 foi superior a 95% com radia??o ultravioleta, a dopagem com ?ons Fe+3 permitiu a ativa??o do semicondutor com radia??o vis?vel. Os comp?sitos de biopl?stico apresentaram grau de cristalinidade inferior ao PLA puro, devido ? incorpora??o de cargas. O equil?brio de adsor??o de n-butanol (Ci = 3500 ppmv, odor n?vel 5) nos comp?sitos de biopl?stico foi atingido entre 40-50 min para as amostras testadas, com um percentual de remo??o entre 54-72%. A fotodegrada??o com radia??o vis?vel foi observada ap?s 45 min de ilumina??o do sistema, a forma??o de CO, CO2 e oxigenados de cadeia curta foi confirmado por cromatografia gasosa. Estes resultados sugerem que os comp?sitos sintetizados neste trabalho, apresentam potencial para as aplica??es testadas.
2

Pesticidas Organoclorados (OCPs) em peixes comerciais capturados na Ba?a de Guanabara do Estado do Rio de Janeiro, Brasil / Organochlorine Pesticides (OCPs) in commercial fish from Guanabara Bay of Rio de Janeiro State, Brazil

FERREIRA, Verona Borges 21 February 2017 (has links)
Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-09-18T13:59:23Z No. of bitstreams: 1 2017 - Verona Borges Ferreira.pdf: 1252759 bytes, checksum: 291a4f24b8d135e118f8e80afed31cfd (MD5) / Made available in DSpace on 2017-09-18T13:59:23Z (GMT). No. of bitstreams: 1 2017 - Verona Borges Ferreira.pdf: 1252759 bytes, checksum: 291a4f24b8d135e118f8e80afed31cfd (MD5) Previous issue date: 2017-02-21 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Brazil is among the world?s largest fish producers, and the state of Rio de Janeiro is one of the main responsible for this production. In addition, there is a substantial increase in fish consumption which is associated to its functional and nutritional properties, such as its lipid profile. Today the hydrographic bays of Rio de Janeiro suffer the impacts of excessive use of toxic substances, such as Organoclorine Pesticides (OCPs), which has a characteristic lipophilicity and tend to accumulate in adipose tissue of organisms. As a consequence, this may pose risk to consumers of fish from polluted environments. The human exposure to these pollutants is highly related to health problems, such as cancer, immunity diseases and endocrine disruptions. Thus, the present study aims at investigating the occurence of OCPs in sardine (Sardinella brasiliensis), whitemouth croaker (Micropogonias furnieri) and mullet (Mugil liza) from Guanabara Bay, located in the state of Rio de Janeiro, and also to estimate the OCPs intake through fish consumption. The analyses were carried out at the Laboratory of de Radioisotopes Eduardo Penna Franca at UFRJ. The analitical steps included sohxlet extration, purification and subsequent injection in a Gas Chromatography system coupled to a Mass Spectrometer on Negative Chemical Ionization mode (GC/MS/ENCI) to determine the OCPs concentrations. The estimative of the toxic compound intake was performed based on the obtained data for OCP in fish samples, the fish intake of the brazilian population, andavailable data of Acceptable Daily Intake (ADI) for each investigated pesticide. All samples had at least one OCP. Metoxichlor had the highest concentration for the three studied species. There was significant difference between the species concerning the concentration of o,p?-DDD and o,p?-DDT. These DDT metabolites were found at higher concentration in sardine samples in comparison to croaker and mullet ones. However, there was no significant difference between the species in relation to ?OCP. It was evidenced the greater proportion of DDE among the DDT metabolites which suggests the past use of this pesticide. Results for ?-HCH isomer indicate the contamination by the use of Lindane instead of the technical HCH mixture. There was no significant difference among the contamination of the three studied species in regard to sample's acquisition locations, showing that the locality does not influence the content of OCPs in fish, probably due the species behavior which travel big distances along the brazilian coast throughout their life cycle. No sample exceeded the maximum residue limit stipulated for OCPs at both national or international level. Based on the estimated intake data no species exceeded the toxicological safety parameter. Thus, the three studied fish species can be considered safe for human consumptiom in regard to OCPs exposure / O Brasil est? entre os maiores produtores mundiais de pescado, sendo o estado do Rio de Janeiro um dos principais respons?veis por essa produ??o. Al?m disso, existe um aumento substancial do consumo de peixes, que est? associado ? suas propriedades nutricionais e funcionais, como o seu excelente perfil lip?dico. As bacias hidrogr?ficas do Rio de Janeiro sofrem hoje os impactos do uso excessivo de subst?ncias t?xicas, como os Pesticidas Organoclorados (OCPs), que devido ? caracter?stica lipof?lica, tendem a se acumular no tecido adiposo de organismos aqu?ticos, o que pode representar um risco a sa?de de quem consome pescado oriundos de ambientes contaminados. Por sua vez, a exposi??o humana a estes poluentes est? altamente relacionada a problemas de sa?de, tais como o surgimento de c?ncer, problemas de imunidade e interfer?ncias end?crinas. Desta forma, o presente estudo tem por objetivo investigar a ocorr?ncia de OCPs em amostras de sardinha-verdadeira (Sardinella brasiliensis), corvina (Micropogonias furnieri) e tainha (Mugil liza) capturados na Ba?a de Guanabara, localizada no estado do Rio de Janeiro, assim como estimar a ingest?o de OCPs por meio do consumo de pescado. As an?lises foram realizadas no Laborat?rio de Radiois?topos Eduardo Penna Franca da UFRJ, atrav?s de sua extra??o, purifica??o e posterior inje??o em um sistema de Cromatografia Gasosa acoplada a um Espectr?metro de Massa por ioniza??o qu?mica negativa (CG/EM/NCI) para determinar as concentra??es de OCPs. Para estimar a ingest?o desses compostos t?xicos foram utilizados os dados de contamina??o das amostras, consumo do pescado pela popula??o brasileira, assim como os dados de Ingest?o Di?ria Aceit?vel (IDA) para cada contaminante. Todas as amostras investigadas estavam contaminadas com pelo menos um OCP, o Metoxicloro foi o pesticida encontrado em maior concentra??o nas tr?s esp?cies estudadas e houve diferen?a significativa entre as esp?cies em rela??o a concentra??o de o,p?-DDD e o,p?-DDT, estes metab?litos do DDT foram encontrados em maior concentra??o nas amostras de sardinha-verdadeira em rela??o as amostras de corvina e tainha, entretanto n?o houve diferen?a significativa entre as esp?cies em rela??o ao ?OCP. Ficou evidenciada a maior propor??o do DDE entre os metab?litos de DDT, n?o sugerindo o uso recente deste pesticida, e do is?mero ?-HCH entre os demais is?meros de HCH, evidenciando a contamina??o pelo uso de Lindano em rela??o ao HCH t?cnico. N?o houve diferen?a significativa entre a contamina??o das tr?s esp?cies com base nos diferentes pontos de coleta, demonstrando que a localidade de aquisi??o do pescado n?o influenciou no teor dessas subst?ncias, uma vez que estas esp?cies ao longo de seu ciclo de vida percorrem grandes dist?ncias pela costa brasileira. Nenhuma amostra excedeu os limites m?ximos de res?duo estipulados para esses contaminantes tanto a n?vel de regulamenta??o nacional quanto internacional. Com base nos dados de estimativa de ingest?o nenhuma esp?cie excedeu o par?metro toxicol?gico de seguran?a, sendo assim, as tr?s esp?cies estudadas s?o consideradas seguras para o consumo humano em rela??o a exposi??o a OCPs

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