LUCAS STANO JUNQUEIRA

LUCAS STANO JUNQUEIRA

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Sedimentary profiles from a water supply reservoir at São Paulo, Brazil
2019 - SILVA, S.A.; JUNQUEIRA, L.S.; FRANKLIN, R.L.; SILVA, W.L.; FAVARO, D.I.T.; MOREIRA, E.G.
A research project has been conducted by the Environmental Company of São Paulo State (CETESB) and the Nuclear and Energy Research Institute (IPEN) in important water supply reservoirs at São Paulo State in order to perform a wide evaluation on the content of rare earths and some trace elements in sediment profiles. In the present study, preliminary results for two sampling campaigns at the Graminha reservoir are presented:February/2015 (sites 1 and 3) and August / 2015 (sites 1 and 2). Sediment core samples (around 90 cm long) were collected in the dam and sliced at every 2.5 cm. Instrumental Neutron Activation Analysis (INAA) was applied to the sediment samples in order to determine some trace elements (As, Cr, Th, U and Zn) and rare earth elements (REE) (Ce, Eu, La, Lu, Nd, Sm, Tb and Yb). The analytical methodology validation was performed by means of certified reference material analyses. As, Cr and Zn concentration values were compared to the oriented values from CCME (Canada) (TEL and PEL). Sediment quality was classified as good or very good for these elements according these criteria. Enrichment factor (EF) and Geoaccumulation Index (IGeo index)1were applied to the results by using the concentration values of the last layer of the 90.0 cm profile as background values for sediment contamination index assessment. EF>1.5 was found for REE, U and Th in the middle of the sediment profiles,in all sampling points, indicative of anthropogenic contribution. IGeo values in the range of1
Trace element assessment in sediment cores from Graminha reservoir, São Paulo State, by INAA
2019 - JUNQUEIRA, LUCAS S.; SILVA, SHARLLENY A.; FRANKLIN, ROBSON L.; FAVARO, DEBORAH I.T.
In the present study, sediment cores were collected in the Graminha (Caconde) water supply reservoir in Feb/2015 (points 1 and 3) and Aug/2015 (points 1 and 4) sampling campaigns. The four sediment cores with different depths were cut every 2.5 cm, yielding 36, 21, 33 and 37 slices of sediments, respectively, that were individually analyzed by INAA (Instrumental Neutron Activation Analysis). This analytical technique was used to quantify the elements: As, Ba, Br, Co, Cr, Cs, Fe, Hf, Rb, Sb, Sc, Ta, Zn, U and Th. The validation of precision of the methodolody was made by analyzing certified reference material. The concentration values obtained for As, Cr and Zn were compared with TEL and PEL oriented values established by the CCME (Canada) and adopted by CETESB for sediment quality evaluation. None of the sediment cores analyzed surpassed the PEL value for these elements. Sediment samples from points 2 and 3 presented the worst sediment quality but were still classified as good quality for sediments. The enrichment factor (EF) and Geoacumulation Index (IGeo) tools used for contamination level assessment were used for all sediment cores and mostly presented enrichment on As and U. The results from concentrations, EF and IGeo showed a significant increase mostly below 30 cm of depth in every core. Statistical analyses were applied to the elemental concentration values for better interpretation of the results.
Avaliação das concentrações de metais, elementos terras raras e traço em perfis de sedimentos do reservatório Graminha - Estado de São Paulo pela técnica de ativação neutrônica
2018 - JUNQUEIRA, LUCAS S.; FAVARO, DEBORAH I.T.
Avaliação das concentrações de elementos terras raras, metais e traço em sedimentos do reservatório graminha, estado de São Paulo, pela técnica de ativação neutrônica
2017 - JUNQUEIRA, LUCAS S.; SILVA, SHARLLENY A.; FAVARO, DEBORAH I.T.
No presente estudo, perfis de sedimentos foram coletados no reservatório de abastecimento Graminha (Caconde), ESP, em Ago/2014 (pontos 1 e 4). Utilizou-se a técnica analítica de Análise por Ativação com Nêutrons Instrumental (INAA) e os elementos determinados foram: As, Ba, Br, Ca, Co, Cr, Cs, Fe, Hf, K, Na, Rb, Sb, Ta, Th, U e Zn e os elementos terras raras (ETRs) (Ce, Eu, La, Lu, Nd, Sm, Sc, Tb e Yb). Os valores de concentração para os elementos As, Cr e Zn foram comparados aos valores orientadores de concentração (TEL e PEL) estabelecidos pelo CCME (Canadá) e adotado pela CETESB. Os sedimentos foram classificados como de qualidade boa ou ótima, para esses 3 elementos. Os valores encontrados nas ultimas fatias do perfil 1(profundidade 90 cm) foram tomados como valores basais de referência e a partir desses valores, calcularam-se os fatores de enriquecimento (FE) e o Índice de Geoacumulação (IGeo). Valores de FE>1,5 foram encontrados, principalmente, para os ETRs, U e Th, em ambos os pontos, indicativo de presença de contribuição antrópica. Os valores de IGeo confirmaram os valores de FE, com valores de 1