Marcos Roberto Lopes do Nascimento

Federal Center for Technological Education of Minas Gerais

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Wilmar Sachetin Marçal

Universidade Estadual de Londrina

Ronaldo Torres

Universidade de São Paulo

Pedro S. Fadini

Universidade Federal de São Carlos

Denis Moledo de Souza Abessa

Universidade Estadual Paulista (Unesp)

Antônio A. Mozeto

Universidade Federal de São Carlos

W. S. Marçal

Universidade Estadual de Londrina

Suzelei Rodgher

Universidade Estadual Paulista (Unesp)

A.A. Mozeto

Universidade Federal de São Carlos

Cláudio Vítor Roque

Nuclear Engineering Institute

Maria Helena Tirollo Taddei

National Nuclear Energy Commission

Cooperative Institutions

National Nuclear Energy Commission

Universidade Federal de São Carlos

Universidade de São Paulo

Universidade Estadual de Londrina

Universidade Estadual Paulista (Unesp)

Nuclear Engineering Institute

Universidade Federal do Ceará

Universidade Santa Cecília

Universidade Federal de São Paulo

Centro de Desenvolvimento da Tecnologia Nuclear

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Ecotoxicological risks of calcium nitrate exposure to freshwater tropical organisms: Laboratory and field experiments

Ecotoxicology and Environmental Safety (2015)

Ana Paula Erbetta Sueitt Thais M. Yamada-Ferraz Aline Fernandes de Oliveira Clarice Maria Rispoli Botta Pedro S. Fadini

Mesocosm

Biota

Calcium nitrate

10.1016/j.ecoenv.2015.03.034

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Citations (16)

Radionuclides and heavy metal contents in phosphogypsum samples in comparison to cerrado soils

Revista Brasileira de Ciência do Solo (2009)

Vanusa Maria Feliciano Jacomino Kerley Alberto Pereira de Oliveira Maria Helena Tirollo Taddei Maria Célia Siqueira Maria Eleonora Deschamps Pires Carneiro

Phosphogysum (PG) or agricultural gypsum, a solid waste from the phosphate fertilizer industry, is used as soil amendment, especially on soils in the Cerrado region, in Brazil. This material may however contain natural radionuclides and metals which can be transferred to soils, plants and water sources. This paper presents and discusses the results of physical and chemical analyses that characterized samples of PG and compares them to the results found in two typical soils of the Cerrado, a clayey and sandy one. These analyses included: solid waste classification, evaluation of organic matter content and of P, K, Ca, Mg, and Al concentrations and of the mineralogical composition. Natural radionuclides and metal concentrations in PG and soil samples were also measured. Phosphogypsum was classified as Class II A - Not Dangerous, Not Inert, Not Corrosive and Not Reactive. The organic matter content in the soil samples was low and potential acidity high. In the mean, the specific 226Ra activity in the phosphogypsum samples (252 Bq kg-1) was below the maximum level recommended by USEPA, which is 370 Bq kg-1 for agricultural use. In addition, this study verified that natural radionuclides and metals concentrations in PG were lower than in the clayey Oxisol of Sete Lagoas, Minas Gerais, Brazil. These results indicated that the application of phosphogypsum as soil amendment in agriculture would not cause a significant impact on the environment.

Phosphogypsum

Amendment

Soil test

10.1590/s0100-06832009000500038

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Citations (17)

Bioaccumulation of Polycyclic Aromatic Hydrocarbons and Mercury in Oysters (Crassostrea rhizophorae) from Two Brazilian Estuarine Zones

International Journal of Oceanography (2012)

Ronaldo Torres Augusto César Camilo Dias Seabra Pereira Rodrigo Brasil Choueri Denis Moledo de Souza Abessa

Nowadays, organisms are increasingly being used in biomonitoring to assess bioavailability and bioaccumulation of contaminants. This approach can use both native and transplanted organisms in order to accomplish this task. In Brazil, most of the studies related to bioaccumulation of contaminants in oysters deal with metals. The present work employs this kind of test in Brazilian coastal estuaries (Santos and Paranaguá) to evaluate total mercury and polycyclic aromatic hydrocarbon contamination in sediments and oysters (native and caged Crassostrea rhizophorae ). The methodologies employed were based on known USEPA methods. Results have shown a significant contamination in Santos sediments and consequent bioavailability of organisms. Paranaguá sediments presented lower contamination in sediments, but native oysters were able to accumulate total Hg. The experiments done with caged oysters did not show significant bioaccumulation of Hg and PAHs in the Paranaguá site, but proved to be an excellent tool to assess bioavailability in the Santos estuary since they were able to bioaccumulate up to 1,600% of total PAH in the samples from the inner part of this estuary when compared to control organisms. Multivariate statistical analyses employed to these results have separated the sites evaluated and the most contaminated samples from the least contaminated.

Bioconcentration

Mercury

Polycyclic aromatic hydrocarbon

10.1155/2012/838320

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Citations (25)

NÍVEIS DOS ELEMENTOS FÓSFORO E FLÚOR NOS SUPLEMENTOS COMERCIALIZADOS EM LONDRINA-PR

Arquivos de Ciências Veterinárias e Zoologia da UNIPAR (2016)

Wilmar Sachetin Marçal Marcos Roberto Lopes do Nascimento Maísa Fabiana Menck

Uma formulação mineral de qualidade para bovinos precisa ser isenta de metais tóxicos e ter em sua composição a correta relação dos elementos fósforo e flúor. Além da obediência a legislação brasileira, é importante primar pela pureza das matérias-primas que compõem qualquer suplemento mineral, para que na cadeia trófica alimentar não haja vulnerabilidade ao consumo de carne e leite pelo ser humano. Para tanto, se faz necessário monitorar os suplementos minerais disponíveis no amplo mercado bovino pecuário, investigando os componentes e suas respectivas relações. Nesta finalidade, a presente pesquisa quantificou os elementos fósforo e flúor em formulações minerais comercializadas na cidade de Londrina, estado do Paraná, onde há expressivo comércio de insumos para a pecuária. Em oito importantes marcas comerciais, os autores encontraram algumas formulações com níveis elevados de flúor, promovendo alteração na relação com o elemento fósforo, caracterizando produtos com padrões fora das normas brasileiras vigentes.

10.25110/arqvet.v18i3.2015.5534

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IDENTIFICAÇÃO E QUANTIFICAÇÃO DE CHUMBO EM MISTURAS MINERAIS COMERCIALIZADAS NO ESTADO DE SÃO PAULO

Ciência Animal Brasileira (2006)

Wilmar Sachetin Marçal Laurenil Gaste Marcos Roberto Lopes do Nascimento

Para se proceder a uma investigacao em misturas minerais, foi realizada uma pesquisa quantificando o elemento chumbo em diferentes formulacoes, comercializadas no Estado de Sao Paulo. O metal pesado foi determinado pela tecnica de espectrofotometria de absorcao atomica por plasma de inducao acoplada. Considerando como parâmetro de comparacao a referencia de MALETTO (1986), em doze diferentes marcas analisadas, oito apresentaram niveis de chumbo inorgânico superiores ao limite maximo aceitavel,que e de 10 ppm. Os resultados demonstram a urgente necessidade de monitoramento junto aos fabricantes e/ou revendedores, pois algumas misturas minerais podem ser eminentemente perigosas, possibilitando efeitos cumulativos toxicos de chumbo inorgânico aos bovinos. PALAVRAS-CHAVE: Bovinos, chumbo, metais pesados, suplementos minerais.

10.5216/cab.v6i4.377

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Citations (1)

INORGANIC LEAD CONCENTRATION IN MINERAL SALT COMMERCIAL MIXTURES FOR BEEF CATTLE IN SÃO PAULO STATE, BRAZIL

Arquivos do Instituto Biológico (2005)

W. S. Marçal Paulo Eduardo Pardo Marcos Roberto Lopes do Nascimento Maíra Salomão Fortes

ABSTRACT The lead concentration in mineral mixtures used in beef cattle in the state of São Paulo, Brazil was measured. The lead concentration was determined by inductively coupled plasma atomic emission spectrometry. Of the 39 analyzed samples (range 3.0 to 4,386 ppm), 28 samples had lead concentration above 10 ppm the acceptable maximum limit proposed by MALETTO (1986). These findings show the necessity for careful industrial monitoring, as some mineral mixtures contain sufficient lead to cause toxicity in animals.

Lead (geology)

Trace Minerals

10.1590/1808-1657v72p3392005

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Citations (2)

Avaliação da integridade superficial da liga AL 2011F

Marcos Roberto Lopes do Nascimento

Com a necessidade de uma melhoria continua na industria metal-mecânica, principalmente para os segmentos automobilistico e aeroespacial, as ligas de aluminio vem ganhando destaque devido as suas caracteristicas como baixa densidade e boa relacao resistencia/peso, alem de poder ser beneficiada por varios tratamentos termicos e facil fabricacao. Dentro dos diversos processos de fabricacao, a usinagem aparece como um dos principais processos utilizados na industria. No processo de usinagem, o acabamento e a etapa que demanda o maior tempo, e a operacao que devemos ter o maior cuidado com o tipo de ferramenta e dados de corte correto, e muitas vezes nao atinge um resultado satisfatorio, seja por falta de conhecimento na area, ou pelo uso errado das ferramentas ou estrategia de corte. O objetivo principal deste trabalho visa promover o estudo da usinagem da liga de aluminio (AA 2011F), por meio da variacao dos parâmetros de usinagem (avanco, raio de ponta da ferramenta, profundidade de usinagem e revestimentos), a fim de observar os valores das rugosidades obtidas no comportamento desta liga em usinagem por torneamento externo para esses parâmetros. Observou-se que para o menor avanco e maior raio de ponta foi conseguido o menor valor de rugosidade em ambas as condicoes de recobrimento de inserto. Notou-se tambem que para a maior profundidade de usinagem, menor avanco e menor raio de ponta houve um comportamento compressivo do ponto de vista da tensao residual. Abstract

10.47749/t/unicamp.2016.974832

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A Critical Comparison of Different Approaches to Sediment-Quality Assessments in the Santos Estuarine System in Brazil

Archives of Environmental Contamination and Toxicology (2014)

Ronaldo Torres Augusto César Victor A. Pastor Camilo Dias Seabra Pereira Rodrigo Brasil Choueri

10.1007/s00244-014-0099-2

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Citations (48)

Determination of Uranium in Environmental Water by Flow Injection Analysis using a Hybrid-Imprinted Polymer

Analytical Letters (2015)

Ayla Campos do Lago Grazielle Cabral de Lima Célio Wisniewski Marcos Roberto Lopes do Nascimento Pedro S. Fadini

A hybrid imprinted polymer was synthesized using 3-(trimethoxysilyl) propylmethacrylate 4 vinylpyridine as the inorganic monomer, metacrilic acid as the organic monomer, and the uranile ion as the template. The synthesis was performed via a sol-gel technique. The polymer was sieved and introduced into a minicolumn, which was coupled in a flow injection system with spectrophotometric detection to preconcentrate uranium and allow its determination at low concentration. The method had a linear dynamic range between 2.0–100 µg L−1, a detection limit of 0.40 µg L−1, a preconcentration factor of 97, a concentration efficiency of 19.4 min−1, a consumptive index of 0.227 mL, and a sampling frequency of 10 analyzes h−1. The imprinted polymer had an adsorptive capacity of 1.77 mg g−1. The method was employed for the determination of uranium in effluent and river water. The precision, expressed as the relative standard deviation, was lower than 5.5%. The accuracy was investigated by comparison with alpha spectrometry; the results were statistically the same. The speed of the process is an advantage compared to the traditional alpha spectrometry. In addition, the present method is green because of the low consumption of sample and reagents and is a useful alternative for uranium determination.

Molecularly imprinted polymer

Enrichment factor

Linear range

Flow injection analysis

10.1080/00032719.2015.1046550

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Citations (7)

Radioecological evaluation (spatial and temporal variation) of the planktonic microorganisms in the Antas Reservoir, Caldas, Minas Gerais, Brazil

Atoms for Peace an International Journal (2010)

L.B. Ronqui Heliana Azevedo Marcos Roberto Lopes do Nascimento José Flávio Macacini Cecilia Roque

The Antas Reservoir (AR) receives treated effluents coming from the acid drainage of uranium ore from the Ore Treatment Unit?Brazilian Nuclear Industries (UTM-INB) plant located in Caldas, Minas Gerais, Brazil. This study was conducted in order to determine the possible radioecological impact caused by discharges of the treated liquid effluent from the UTM into the reservoir. Biological and physicochemical variables were evaluated in the present study. Sampling in the AR (Cab, P41, P14S and P14F points) took place during the dry winter (July 2006) and rainy summer seasons (February 2007). Each day, samples were collected four times (6:00 am, 12:00 noon, 6:00 pm and 12:00 midnight). The average trophic state index values obtained for samples in the dry and rainy periods allowed the areas to be classified as oligotrophic and mesotrophic, respectively. Chemical parameters indicated failures in the nuclear facility effluent treatment system, showing that effluents discharged at P41 do not agree with the standards that have been established by the Brazilian current legislation for Class II water. These results agreed with biological analyses, since P41 has the lowest density values for ciliated protozoa, indicating possible environmental impacts on the ecosystem due to the release of effluents by the mining company.

10.1504/afp.2010.031020

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Citations (2)