ANDRE RODRIGO DA SILVA

ANDRE RODRIGO DA SILVA

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Radionuclides of natural origin in environmental samples collected in the catchment area of Ponte Nova reservoir, São Paulo, Brazil
2018 - SILVA, A.R.; DAMATTO, S.R.; LEONARDO, L.; GONÇALVES, P.N.; SOUZA, J.M.; MADUAR, M.F.
Natural radiation is generally classified as terrestrial primordial radiation or cosmogenic radiation. Primordial radiation is mostly due to the decay series of 238U and 232Th and is present in soil, sediments and water; another important source of natural radiation is 40K. Reservoirs are a very dynamic system with several phenomena to study, due to their huge impact on ecosystems and river flow. Ponte Nova reservoir (23°34'43.23"S, 45°56'56.76"W) is the first reservoir in a cascade system that was built in the 1970s to control the Upper Tietê River basin water flow. In the present work, the activity concentrations of 238U, 226Ra, 210Pb, 232Th, 228Th, 228Ra and 40K were determined using instrumental neutron activation analysis and gamma spectrometry in soil profiles collected in the catchment area of Ponte Nova Reservoir and sediment cores collected close to the soil samples. The highest concentration obtained in the soil samples was for 40K that varied from 49 to 2410 Bq/kg and 210Pb in the sediment samples, which varied from 20 to 774 Bq/kg. Cluster analysis and principal component analysis were applied to all the results obtained to verify a probable correlation between the radionuclides determined in the soil and sediment samples.
Distribuição vertical de radionuclídeos naturais das séries do 238U, 232Th e 40K e caracterização química inorgânica de perfis de solo e de testemunhos de sedimento coletados na área de influência do reservatório de Ponte Nova do estado de São Paulo
2018 - SILVA, ANDRÉ R. da
As radiações provindas do solo e dos sedimentos constituem um aspecto importante da caracterização geofísica e geoquímica do ambiente. Essas radiações são emitidas por radionuclídeos que podem ser: naturais ou artificiais. Assim, como os radionuclídeos os elementos maiores e traços representam peça fundamental na caracterização química de solos e sedimentos e também estão sujeitos a alterações em suas concentrações devido à atividade antrópica, como a construção de uma represa. O reservatório de Ponte Nova, localizado no estado de São Paulo, é de importância de abastecimento e econômica às populações da região leste da Região Metropolitana de São Paulo. Neste trabalho foram determinadas as concentrações de atividade dos radionuclídeos naturais da série de decaimento do 238U, e da série do 232Th e o radionuclídeo 40K, elementos maiores e traços coletados em perfis de solo e testemunhos de sedimento na área de influência do reservatório de Ponte Nova. As concentrações de atividade dos radionuclídeos apresentaram médias de: 40K com 275,6(54) Bq kg-1, 238U com 49,00(24) Bq kg-1, 226Ra com 43,7(2) Bq kg-1, 210Pb com 91(2) Bq kg-1, 232Th com 99(1) Bq kg-1, 228Th com 84(1) Bq kg-1 e 228Ra com 74,0(7) Bq kg-1, que estão acima da média da UNSCEAR. Os elementos maiores e traços apresentaram médias de: As com 4,75(8) mg kg-1, Ba com 306(3) mg kg-1, Br com 20,7(4) mg kg-1, Ca com 136,8(5) g kg-1, Ce com 151(2) mg kg-1, Co com 7,4(2) mg kg-1, Cr com 30,0(5) mg kg-1, Cs com 2,53(2) mg kg-1, Eu com 628(6) μg kg-1, Fe com 43,7(10) g kg-1, Hf com 10,30(8) mg kg-1, K com 13,1(2) g kg-1, La com 54(1) mg kg-1, Lu com 764(7) μg kg-1, Na com 852(9) mg kg-1, Nd com 33,5(5) mg kg-1, Rb com 43,0(5) mg kg-1, Sb com 0,56(1) mg kg-1, Sc com 12,2(2) mg kg-1, Se com 646(6) μg kg-1, Sm com 6,44(6) mg kg-1, Ta com 1,49(1) mg kg-1, Tb com 650(4) μg kg-1, Th com 24,2(2) mg kg-1, U com 2,53(1) mg kg-1, Yb com 1,86(2) mg kg-1 e Zn com 56(1) mg kg-1. Os parâmetros de qualidade de solo e sedimento também são apresentados. Vários elementos apresentaram fator de enriquecimento alto como Hf, Fe e As; no entanto, apesar do fator de enriquecimento alto, os índices de geoacumulação não indicam nenhuma poluição presente. Para verificar se existia correlações entre as concentrações obtidas foram aplicadas as análises estatísticas de matriz de correlação, análise de grupos e dos componentes principais.
Inorganic chemical characterization of the soil and sediment from Taiaçupeba Reservoir, São Paulo
2017 - LEONARDO, L.; SOUZA, J.M.; DAMATTO, S.R.; SURKOV, A.M.; MADUAR, M.F.; SILVA, A.R.
Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê –SPAT) and it is responsible for water supply for about 3.1 million of people. The water quality of a reservoir became very important in the last decades due to the increase of environmental degradation of the soil and its several uses. Trace and major elements can accumulate in high levels in soil and sediment, and the study of its concentration can indicate if the ecosystem is polluted. Therefore, the study of soil profiles and sediment cores are an important tool for the understanding of geophysical and geochemical aspects of aquatic ecosystems. The objective of this work was to present the elements As, Ba, Br, Ca, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Ta, Tb, Th, U, Yb and Zn concentrations using Instrumental Neutron Activation Analysis (INAA) in four soil profiles and four sediment cores collected in the influence area of Taiaçupeba reservoir. To verify if these elements could be enriched and the ecosystem polluted the Enrichment Factor and the Geoacumulation Index were also used. Soil profiles were collected in trenches up to 2m deep and sampled every 5 cm; in the laboratory the samples were dried at room temperature. The sediment samples were collected with a manual PVC sampler sliced every 2 cm or according to their textural characteristics, and dried in an oven at 50 C; the length of the sediment cores ranged from 42 cm to 61 cm. After drying, soil and sediment samples were sieved in a 2 mm mesh and packed in polyethylene bottles for INAA. The elements Na, As and Sb presented the highest values for both soil and sediment samples, implying in continuous, regular and spatial monitoring of the reservoir. One sediment core presented a very high concentration of the element Zn when compared to the values of the Upper Continental Crust, indicating a possible anthropic contribution from the region’s industries and classifying the reservoir as extremely polluted in relation to this element. In the evaluation of the enrichment factor it was concluded that the soil presented very high enrichment for the elements Na, As and Sb and the sediment presented very severe enrichment for the elements Na, As and Zn.
Major, minor and trace elements determination using INAA in soil profile and sediment core samples collected in the catchment area of ponte nova reservoir, São Paulo – Brazil
2017 - SILVA, A.R.; DAMATTO, S.R.; LEONARDO, L.; SOUZA, J.M. de; GONÇALVES, P.N.; MADUAR, M.F.
Elemental Chemical Characterization is a keystone in understanding environmental phenomena and its effects. Major and trace elements give important data about geological, physical, chemical and biological phenomena undergoing in natural environments. Ponte Nova reservoir (23 34’43.23" S, 45 56’56.76" W) is the first reservoir in a cascade system that was built in the 1970s to control Upper Tietê River basin water flow. Nowadays, this reservoir serves as a source of water for agricultural and industrial enterprises and as drinkable water source, and were a major concern for the population of São Paulo state due to a recent severe drought in the years of 2014 and 2015. In the present work, major and trace elements (As, Ba, Ce, Co, Cr, Cs, Eu, Fe, Hf, K, La, Lu, Na, Nd, Rb, Sb, Sc, Sm, Tb, Yb and Zn) were determined using Instrumental Neutron Activation Analysis (INAA) in the IEA-R1 nuclear reactor using the comparative method. This procedure consists in exposing 200mg of the sample and reference materials sealed in polypropylene bags to a thermal neutron flux of 1 1012 cm􀀀2s􀀀1. Geo-accumulation indexes and enrichment factors were determined and physicochemical parameters (grain size analysis, pH, real and apparent densities, Loss on Ignition, porosity and humidity) were measured. The major and trace element concentrations were compared with the Upper Continental Crust values. Cluster analysis, correlation matrix and principal component analysis were applied in all the results obtained to verify a probable correlation between the major and trace elements determined in the soil and sediment samples.
Natural radionuclides from U-238 and TH-232 series and inorganic chemical characterization of soil profiles and sediment cores of the Taiaçupeba Reservoir, São Paulo, Brazil
2017 - SOUZA, J.M.; DAMATTO, S.R.; LEONARDO, L.; SURKOV, A.M.; SILVA, A.R.; MADUAR, M.F.; GONÇALVES, P.N.
Taiaçupeba reservoir, located in the state of São Paulo, Brazil, belongs to Producer System of Alto Tietê (Sistema Produtor Alto Tietê) and it is responsible for water supply for about 3.1million of people. The water quality of a reservoir is very important, but this is reduced by the increase of environmental degradation of the soil around the reservoir and its different uses. The study of soil profiles and sediment cores is an important tool for understanding the geophysical and geochemical aspects of an aquatic ecosystem. The objective of this work was to present the natural radionuclides 238U, 226Ra, 210Pb, 232Th, 228Th, 228Ra and 40K activity concentrations and also the inorganic chemical characterization of four soil profiles and four sediment cores collected in the area of influence area of Taiaçupeba reservoir. The analytical techniques, gamma spectrometry and instrumental neutron activation analysis were used in the determination. In the soil profiles the highest activity concentrations were obtained for the radionuclides 40K and 228Th and the lowest for 210Pb; in the sediment cores the highest activity concentrations were obtained for the radionuclide 210Pb and the lowest for 226Ra and 228Ra. For the inorganic chemical characterization the highest values obtained were for Na, As and Sb; in a sediment core a very high concentration was obtained for the element Zn indicating a probable accumulation of this element inside the reservoir; enrichment factor was used to evaluate a possible anthropic contamination in the soil and sediment at the margins of Taiacupeba reservoir.
Assessment of natural radionuclides of the 238U and 232Th series determined in soil profiles and sediment cores from Taiaçupeba reservoir, São Paulo, Brazil
2016 - SOUZA, JOSEILTON M.; DAMATTO, SANDRA R.; LEONARDO, LUCIO; SURKOV, ANDREY M.; SILVA, ANDRE R.; MADUAR, MARCELO F.; GONÇALVES, PEDRO N.