Navegando por Assunto "Hidrocarbonetos"

Agora exibindo 1 - 3 de 3

Análise estrutural e uso de lacase de camarão para a degradação de antraceno
(2022-10-19) Silva, Larissa Celestino da; Buarque, Diego de Souza; http://lattes.cnpq.br/7609652740088882; http://lattes.cnpq.br/5589996843765879
Through the large population growth and technological development, the use of natural resources has become increasingly present and constant, also causing concerns, measures and solutions related to the environment. In this context, the oil spill has affected aquatic ecosystems. Furthermore, petroleum comprises a series of polycyclic aromatic hydrocarbons, which are not very volatile and are deposited at the bottom of aquatic environments. Therefore, the use of laccase enzymes can be used to combat petroleum hydrocarbons. The structure of the L. vannamei laccase showed conserved domains characteristic of this enzyme, such as those that are important for copper centers, since they are responsible for carrying out the oxidation of aromatic compounds. In addition, the sequence of this enzyme showed a higher percentage of identity when compared to the laccases of other organisms, this fact can be characterized due to the number of identical positions existing between their amino acid sequences. The present work addressed the use of bioinformatics tools to understand the structure of the laccase and, consequently, test the activity of the enzyme in the degradation of the anthracene hydrocarbon.
Avaliação da contaminação ambiental por hidrocarbonetos do petróleo em sedimentos do rio Ipojuca, Caruaru, Pernambuco, Brasil
(2021-06-15) Moreira, Thayane Cristina da Silva; Santos, Jandyson Machado; http://lattes.cnpq.br/4137257750865101; http://lattes.cnpq.br/0370512046415428
The hydrographic basin of the Ipojuca River, in the state of Pernambuco, Brazil, is about 320 km long and includes 25 municipalities, one of which is the city of Caruaru, which is a municipality of regional importance, representing approximately 2.43% of the state GDP. In the region, the river is used for leisure, fishing, human, agricultural, and industrial supply, and may be exposed to several contaminants, including those from the use of petroleum derivatives. Therefore, it is extremely important to evaluate the level of contamination and the impact caused to these aquatic environments, through the identification with geochemical biomarkers, aiming to identify the compounds of the classes of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs), which are considered bioaccumulative and toxic and may have carcinogenic and mutagenic potential. The present study aimed to carry out the chemical characterization of ten surface sediment samples collected from the Ipojuca River, in the stretch related to the municipality of Caruaru/PE, in order to identify and quantify HAs and PAHs, to obtain the level of contamination of the aquatic system. The HAs were detected with carbon numbers from C15 to C37, which, through diagnostic ratio calculations, such as the preferential carbon index (PCI), indicated contamination sources of petrogenic and biogenic origin in the sediments. The isoprenoids pristane (Pr) and phytane (Ft) were also identified in all sediments, where the Pr/Ft ratio pointed to contamination referring to the presence of petroleum hydrocarbons. For PAHs, it was possible to identify and quantify 21 compounds, which, according to the absolute concentration values and through the diagnostic ratios, could classify the contamination level of the field sediments in a moderate to a high degree, indicating petrogenic and pyrogenic sources in the formation of organic matter in the sediments. Thus, it was possible to infer that the studied aquatic system is with a relevant contamination level for the studied compounds. Thus, it is expected that the results obtained can help agencies responsible for the preservation and recovery of the Ipojuca River.
Confinamento eletrônico em hidrocarbonetos policíclicos aromáticos
(2021-07-23) Ramos, Renata Silva de França; Bastos, Cristiano Costa; http://lattes.cnpq.br/6385190604693576; http://lattes.cnpq.br/6599123329831719
The polycyclic aromatic hydrocarbons (PAHs) are componds that contain one or more benzene rings together. Therefore, exist in these molecular systems the called ressonance [pi] electrons that could be more weakly connected. This ressonance it is one of the determining aspects of the aromacity molecular. The ressonance is related the fusion structure on one compond and to displaced electrons that has distributed the character of the multiple bonds. The PAHs’s ressonance [pi] electrons can be seen how free electrons confined in the region molecule. The quantum theory brings a intrinsic model for the eletronic confinement, in this case the molecular external ambient is not considered. For another approach, the extrinsic model we consider the molecular external ambient. The intrinsec model approach can be studied leading to the solution of the electronic spectra of molecules fot this confinement. In the present work we consider that in PAH we can have more than one confinement region. As a direct consequence we have more possibilities, for example for the first transition state. The PAH present electronic transitions in the region of the UV-Vis spectra, which we seek in this work to correlate with the confinement theories. Using only the particle model in which the results are obtained through intrinsic and extrinsic confinement. Other than the level energies, the energy differences in the two approaches are the same. We apply the intrinsic [pi] electron model to benzene, naphthalene, anthracene, tetracene, pentacene, hexacene, heptacene, octacene, nonacene and decacene molecules. We were able to predict one peak for benzene, one peak for pentacene and five peaks for the tetracene spectrum. It was possible to predict the maximum UV-Vis wavelengths for the studied PAHs. For this model, the application in PAH was consistent with the results found in the literature. We compared these wavelength results from the UV-Vis spectrum using the theoretical quantum chemistry method of the confined particle model and the computacional ZINDO method.