Avaliação da alteração molecular na composição química de petróleo nos estágios iniciais de contato com ambientes aquáticos

• Ano de defesa: 2019
• Autor(a) principal: Carregosa, Jhonattas de Carvalho
• Orientador(a): Wisniewski Junior, Alberto
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Programa de Pós-Graduação: Pós-Graduação em Química
• Palavras-chave em Português: Química; Petróleo; Óleos e gorduras; Impacto ambiental; Resinas; Processos químicos; Óleo bruto; Saturados, aromáticos, resinas e asfaltenos (SARA); Espectrometria de massas com transformada de Fourier (FTMS)
• Palavras-chave em Inglês: Fourier Transform - Mass Spectrometry (FTMS); Orbitrap; Petroleum; Crude oil; Environmental impact; Resins
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/11893

Accidents involving oil leakage, such as that recently occurred in the Guanabara basin/RJ - Brazil, are sources of constant research on the potential toxicities of the environment. The oil when released in the environment goes through several compositional changes and understanding them helps in understanding the assessment of the risks to the impacted environment. Thus, classical techniques, such as SARA fractionation, elemental analysis, and gas chromatography (GC), along with the advanced technique ESI(±)-FTMS technique, allowed a comprehensive study in the evaluation of molecular changes in the oils composition during the first 72 hours of contact with saline and fluvial aquatic environment. The results showed that in the very first hours of exposure to the fluvial environment, the saturated fraction suffered a decreasing for both crudes tested, the most significant was observed to the medium oil, which have a loss of 16%, as for the heavy one, only 4%. The aromatics fraction also suffered an impact of 11% and 5%, respectively, for the same environment. The Ph/n-C18 and Pr/n-C17 ratios have identified a slight contribution of microbiological biodegradation to oils in contact with the marine environment and a more systemic one for those who had contact with the fluvial environment. It was observed an increase of the resinous fraction of the oils for both environments in ~10%, besides the alteration of the elemental composition suffered by the oils in contact with the respective aquatic environments. In general, the relative intensity of class O2 almost doubled, regardless of the oil or environment to which it was inserted. The oil of lower ºAPI showed the most outstanding class was the N1 for ESI(-) analysis. Through the evaluation of the resin fraction by ESI(+), this study showed that the N1 class, which contains carbon numbers larger than C50 and DBE greater than 15 greater presented higher susceptibilities to photooxidative processes.