Título: | STUDIES ON THE ORIGIN AND TRANSFORMATION OF SELENIUM AND ITS CHEMICAL SPECIES ALONG THE PROCESS OF PETROLEUM REFINING | |||||||
Autor: |
CIBELE MARIA STIVANIN DE ALMEIDA |
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Colaborador(es): |
NORBERT FRITZ MIEKELEY - Orientador |
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Catalogação: | 15/SET/2008 | Língua(s): | PORTUGUESE - BRAZIL |
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Tipo: | TEXT | Subtipo: | THESIS | |||||
Notas: |
[pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio. [en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio. |
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Referência(s): |
[pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=12188&idi=1 [en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=12188&idi=2 |
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DOI: | https://doi.org/10.17771/PUCRio.acad.12188 | |||||||
Resumo: | ||||||||
Different spectrometric methods of analysis, including ICP
OES, ICP-DRC-MS and
Q-ICP-MS, the latter hyphenated to hydride generation,
eletrothermal vaporization or ion
chromatography have been appliesd to the chemical
characterization of 16 crude oils
and 41 effluents samples from a petroleum refinery. The
specific objective of this study
was to get information on the behavior of selenium (Se) and
its species along the
different processes of generation and treatment of the
effluents.Multielemental
characterization of effluents by ICP-MS revealed a complex
composition of most of them,
with high salinity and potential spectral and non spectral
interferents present. For this
reason, a critical reassessment of the analytical
techniques for the determination of total
Se and its species was necessary. DRC-ICP-MS and ETV-ICPMS,
using CH4 as cell
reaction gas, showed their potential for the determination
of Se with better detection
limits (about 0,05 ug L-1), but also their limitations for
the analysis of effluents with high
salinity. A large variability in the concentration of Se
was observed in the 16 analysed
crude oil samples (< 10 ug kg-1 Se until up to 960 ug kg-1),
which may explain also the
varying concentrations measured in the effluents. Highest
concentrations of selenium
were measured in samples from the treatment unit for acid
waters (up to 1.714 ug L-1).
The predominance of selenocyanate (SeCN-1) was confirmed in
most of the effluent
samples analysed, but also several other species with
retention times different from
Se(IV), Se(VI) e SeCN - were observed, especially in samples
from the treatment plant.
Colloidal Se (Seº) was identified in acid waters, probable
formed by decomposition of
SeCN - or other unstable species under these conditions.
Laboratory experiments with
selenocyanate solutions confirmed this hypothesis. The
speciation profile of samples
collected at the same point, but at different time
intervals, showed significant variations,
not allowing easy comparison of the results obtained in
this work with those of other
authors.
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