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

• Ano de defesa: 2019
• Autor(a) principal: Castiblanco, Julián Eduardo Ballén
• 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; Solos; Poluição por óleo; Areia; Compostos saturados do óleo; Resinas; Saturados, aromáticos, resinas e asfaltenos (SARA)
• Palavras-chave em Inglês: Espectrometria de massas com transformada de Fourier (FTMS); Crude oil; Soil; Sand; Saturates; Resins; Fourier Transform - Mass Spectrometry (FTMS)
• Área do conhecimento CNPq: CIENCIAS EXATAS E DA TERRA::QUIMICA
• Link de acesso: http://ri.ufs.br/jspui/handle/riufs/11892

Contamination of terrestrial environments by oil spills is a recurrent fact in the world, which creates biological risks to human´s and ecosystem´s health. The studies about oil spill aim to evaluate the toxicity and changes in the chemical composition of soils and waters, in a field of potential interest to the scientific community. In this context, the present work evaluated the changes in the chemical composition of crude oil fractions after the simulation of a spill in soil and sand, with emphasis on an immediate temporal investigation. Were used samples of medium and heavy oils from the Sergipe-Alagoas basin, soil from the rural area of São Cristóvão-SE and sand from Atalaia´s beach in Aracaju- SE. The simulations were performed with a 40:1 (m/m) mixture of terrestrial:oil with direct influence of a 60 W lamp with cycles of 12 hours per day. The aliquots of soil and sand were taken from the system at times of 1, 12, 24, 48 and 72 h, then were extracted with n-hexane/dichloromethane/methanol (7:2:1) and submitted to SARA fractionation in micro column and GC-FID analysis. SARA gravimetric data showed that the saturated fraction decreased 14.2 % and 3.7 % for the medium oil that interacted with soil and sand respectively. On the other hand, the saturated fraction of heavy oil decreased 16.8% and 14. 7 % when it interacted with soil and sand respectively. It was highlighted the evaporation process in the soil; while the GC-FID chromatographic profiles demonstrated the disappearance from n-C12 until n-C14 compounds, besides a decrease of more than 50% in n-C15 and n-C16 n-alkanes. The absolute aromatic and resins fractions remained constant during the exposure time (1 h to 72 h) for both environments and oils. Analysis of resins fraction performed by Orbitrap-MS, have shown changes in the mass spectra profile during the soil exposure process, with N1, O1,ad O3 species showing the greatest changes in the relative intensity in ESI(+) mode, O2, N1, O3 and O1 for ESI(-). Changes in polar oil compounds will depend on the extent of the time they interact with soil and sand, taking into account aspects such as the nature of the soil and components in it as the organic matter.