FLAVIO ROBERTO ROCHA
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Artigo IPEN-doc 30344 Oyster shell element composition as a proxy for environmental studies2024 - SILVA, PAULO S.C. da; FARIAS, WELLINGTON de M.; GOMEZ, MAURO R.B.P.; TORRECILHA, JEFFERSON K.; ROCHA, FLAVIO R.; SCAPIN, MARCOS A.; GARCIA, RAFAEL H.L.; SIMONE, LUIS R.L. de; AMARAL, VANESSA S. de; VINCENT, MOUCHI; LAURENT, EMMANUEL; RUDNICKI-VELASQUEZ, PAWELThe use of mollusks' shell as a proxy for long-term trend prediction in the variability of coastal zones has been used as an attempt to understand the consequences that environmental changes may cause to the functioning of coastal ecosystems. This study exploited the elemental concentration, elemental ratios and mineralogy of oyster shells of the genus Crassostrea to infer spatial variations in the environment of the animal's growth. Modern oyster shell samples of the Crassostrea brasiliana and Crassostrea mangle species were analyzed by neutron activation analysis, X-ray diffraction, X-ray fluorescence and Graphite Furnace Atomic Absorption Spectrometry. Data normalization by the enrichment factor relative to lanthanum (La), considered as a conservative element in seawater, and statistical multivariate analyses indicate that the elemental composition and trace element ratios differ when comparing oyster shells from different regions. The results showed that the performed analyses may be useful for the characterization of the environment in which oysters grow.Artigo IPEN-doc 28500 Trace and major elements, natural and artificial radionuclides assessment in bottom sediments from Tietê River basin, São Paulo State, Brazil2022 - MAZZILLI, BARBARA P.; LAVIERI, LETICIA G.S.; SOARES, JOSIANE S.; ROCHA, FLAVIO R.; ANGELINI, MATHEUS; FAVARO, DEBORAH I.T.This paper aims at quantifying natural and artificial radionuclides, trace and major elements in sediments collected along the Tietê River basin. The results obtained for Cd, Cr, Cu, Ni and Zn, indicated that the region of “High Tietê” is highly polluted, followed by the region of “Middle Tietê” and the region of “Low Tietê” does not present evidence of contamination. The natural radionuclide concentrations were of the same order of magnitude of world average values and can be defined as basal levels of the region. Cesium-137 activity concentration ranged from 0.22 ± 0.08 Bq kg−1 to 0.96 ± 0.12 Bq kg−1.Artigo IPEN-doc 24228 Avaliação e distribuição de metais, elementos traço e terras raras em perfis de sedimentos do reservatório de promissão, estado de São Paulo, por INAA2017 - ANGELINI, MATHEUS; FRANKLIN, ROBSON L.; ROCHA, FLAVIO R.; FAVARO, DEBORAH I.T.O presente estudo avaliou a concentração de elementos em dois pontos do reservatório (1 e 3). Foram coletados 2 perfis de sedimentos fracionados em campo, a cada 2,5 cm, gerando 14 e 20 frações, respectivamente, de acordo com as suas profundidades (35 e 50 cm). Utilizou-se a técnica de Análise por Ativação com Nêutrons Instrumental (INAA) e foram determinadas as concentrações dos elementos: As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Rb, Sb, Sc, Ta, Th, U, Zn e os elementos terras raras (Ce, Eu, Gd, La, Lu, Nd, Sm, Tb e Yb). A validação da metodologia foi feita através das análises de materiais de referência certificados. Os valores do NASC (North American Shale Composite) foram utilizados como valores de referência para cálculo de Fator de Enriquecimento (FE) e Índice de Geoacumulação (IGeo), ferramentas utilizadas para avaliação de níveis de poluição. Comparou-se também a concentração dos elementos As, Cr e Zn com os valores orientadores TEL (Treshold Effect Level) e PEL (Probable Effect Level), valores que fornecem faixas de concentração para esses elementos indicando a presença ou não de prováveis efeitos na biota aquática advinda dessas concentrações.Artigo IPEN-doc 24086 Metal and trace element concentration evaluation in sediment profiles of the Tietê River, State of São Paulo, by INAA and ICP OES techniques2017 - SOARES, JOSIANE S.; ROCHA, FLAVIO R.; FAVARO, DEBORAH I.T.The present study presents concentration results for heavy metals, major and trace elements, in two sediment cores collected along the Tietê River: Salto de Itu to Porto Feliz ( Core 4 at point T-5) and Laras to Anhembi (Core 6 at point T18). As, Ba, Br, Co, Cr, Cs, Hf, Rb, Sb, Sc, Ta, Th, U and Zn concentrations by Instrumental Neutron Activation Analysis (INAA) and Al, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Ti, V and Zn concentrations by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES) were determined. The enrichment factor (EF), to assess the presence of anthropogenic pollution sources, was calculated and showed FE > 1.5 values for As, Br, Cs, Hf, Rb, Ta, Th, U and Zn, confirming the anthropogenic contribution for these elements, in all fractions from both cores. As, Cd, Cr, Cu, Ni, Pb and Zn concentrations were compared to guideline values (TEL and PEL) from the Canadian Council of Ministers of the Environment (CCME) and adopted by the São Paulo State Environmental Company (CETESB) and concentration values between TEL and PEL were found, for all fractions from both cores, presenting good and or regular sediment quality classification, the worst being Core 6.Resumo IPEN-doc 21548 Trace elements by neutron activation analysis in three sediments cores from the Alto Tietê River sub-basin, São Paulo-Brazil, dated by 210Pb method2015 - FAVARO, DEBORAH; ROCHA, FLAVIO; DAMATTO, SANDRA R.; WAKASUGI, DENISE; SILVA, PAULO S.