Instituto Nacional Of Ciencia E Tecnologia Energia And Ambiente

Salvador, Brazil

Instituto Nacional Of Ciencia E Tecnologia Energia And Ambiente

Salvador, Brazil
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Nicolini J.,Federal University of Paraná | Pereira B.F.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | Pillon C.N.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | MacHado V.G.,Federal University of Santa Catarina | And 6 more authors.
Journal of Analytical and Applied Pyrolysis | Year: 2011

The Brazilian oil shale byproducts resulting from the Petrosix pyrolysis (retortage) process were submitted to a set of analytical techniques to evaluate their possible use as agricultural soil conditioners. Liquid dichloromethane extracts from the solid samples were analyzed using capillary column gas chromatography-mass spectrometry. The results showed that of the 16 PAHs designated by the U.S. EPA as priority pollutants, only phenanthrene, fluorene and naphthalene, present in the retorted oil shale sample taken from inside storage piles; benzo[k]fluoranthene, present in the dolomite limestone layer between the two layers of oil shale in the mine structure; and naphthalene, present in powdered raw oil shale, were above the limits established by the EPA. The solid Brazilian oil shale byproduct samples were also analyzed by X-ray diffractometry (XRD), diffuse reflectance ultraviolet-visible spectroscopy (DRUV-VIS), X-ray fluorescence spectroscopy (XRF) and electron paramagnetic resonance (EPR) spectroscopy. The XRD analysis showed that the pyrolysis process produces a "weathering" transformation, for example with the appearance of kaolinite diffraction lines in the retorted samples. The DRUV-VIS and XRF spectroscopy results indicated iron oxide goethite interactions with the PAHs present in the solid samples studied. The EPR spectroscopy showed that the samples row oil shale (g = 2.0044) and the powder oil shale (g = 2.0035), before the dichloromethane extraction, presented organic free radical signals associated with oxygen atoms. The other Brazilian oil shale byproduct samples, before and after the dichloromethane extraction, showed organic free radical signals associated with carbon atoms (g = 2.0022-2.0031). © 2010 Elsevier B.V. All rights reserved.

Martins C.C.,Federal University of Paraná | Doumer M.E.,Federal University of Paraná | Gallice W.C.,Federal University of Paraná | Dauner A.L.L.,Federal University of Paraná | And 9 more authors.
Environmental Pollution | Year: 2015

Abstract Spectroscopic and chromatographic techniques can be used together to evaluate hydrocarbon inputs to coastal environments such as the Paranaguá estuarine system (PES), located in the SW Atlantic, Brazil. Historical inputs of aliphatic hydrocarbons (AHs) and polycyclic aromatic hydrocarbons (PAHs) were analyzed using two sediment cores from the PES. The AHs were related to the presence of biogenic organic matter and degraded oil residues. The PAHs were associated with mixed sources. The highest hydrocarbon concentrations were related to oil spills, while relatively low levels could be attributed to the decrease in oil usage during the global oil crisis. The results of electron paramagnetic resonance were in agreement with the absolute AHs and PAHs concentrations measured by chromatographic techniques, while near-infrared spectroscopy results were consistent with unresolved complex mixture (UCM)/total n-alkanes ratios. These findings suggest that the use of a combination of techniques can increase the accuracy of assessment of contamination in sediments. © 2015 Elsevier Ltd.

Balena S.P.,Federal Technological University of Paraná | Balena S.P.,Federal University of Paraná | Messerschmidt I.,Federal University of Paraná | Tomazoni J.C.,Federal Technological University of Paraná | And 6 more authors.
Journal of the Brazilian Chemical Society | Year: 2011

Electron paramagnetic resonance (EPR) spectroscopy and optical analyses of intensively weathered soils containing high levels of oxide-hydroxide of iron from a pilot project on precision agriculture, including 13 farms in the southwest of Paraná state, Brazil, were carried out, aiming at defining parameters of soil fertility. The results of the optical studies in the laboratory were compared with those obtained by the use of a portable spectroradiometer in field conditions. The studied soils were mainly composed of 1:1 clay minerals, oxides and oxide hydroxides of iron (mainly goethite and hematite) and aluminum (mainly gibbsite), characteristics of highly weathered soils, as for example Ferralsols. The EPR spectra, typical of mutual magnetic interaction of aggregated Fe 3+ ions, showed a signal linewidth increase at g ca. 2 upon cooling. This phenomenon can be caused by changing the crystal field environment of Fe 3+ ions or by the spin-spin relaxation mechanism, which causes an increase of linewith when the temperature decreases. The optical spectral curves obtained from the portable spectroradiometer presented less detailed but more specific features for each soil sample analyzed. The results indicate that use of the portable spectroradiometer along with mathematical tools such as the second derivative mode of the Kubelka-Munk function is a good alternative to analyze clay soils rich in metallic oxide and oxide hydroxides. A full attribution of the spectra features was made, mainly for the electronic transitions between energy levels into Fe 3+- Fe 3+ couples. ©2011 Sociedade Brasileira de Química.

Dos Santos J.V.,Federal University of Paraná | Mangrich A.S.,Federal University of Paraná | Mangrich A.S.,Instituto Nacional Of Ciencia E Tecnologia Energia And Ambiente | Pereira B.F.,EMBRAPA - Empresa Brasileira de Pesquisa Agropecuária | And 5 more authors.
Journal of the Brazilian Chemical Society | Year: 2013

In this work, native forest soil (NFS) organic matter (SOM) sample and SOM samples from a neighboring forest soil area of an oil shale mine which is being rehabilitated for thirty years (RFS) were analyzed. X-band electron paramagnetic resonance (EPR) and solid-state 13C nuclear magnetic resonance (NMR) spectroscopies were used to evaluate the soil reclamation of the Brazilian oil shale mining process. Two-dimensional heterospectral correlation studies of the results obtained from EPR and 13C NMR were used to obtain information about SOM structures and their interactions with residual paramagnetic metal ion. The signal of the residual metallic oxycation, VO2+ correlated positively with uronic acid-type hydrophilic organic structures, determined from the 13C NMR spectra, and correlated negatively with the organic free radical (OFR) signal associated with oxygen atoms (g = 2.0042). The hydrophobic aromatic structures correlate positively with the EPR OFR signal associated with carbon atoms (g = 2.0022). The data from the two spectroscopic magnetic techniques show that the used recuperation process is effective. © 2013 Sociedade Brasileira de Quimica.

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