Soil and sediment geochemistry of the iron quadrangle, Brazil the case of arsenic

Deschamps, Eleonora; Ciminelli, Virgínia S. T.; Lange, Frank Thomas; Matschullat, Jörg; Raue, Brigitte; Schmidt, Hanka

doi:10.1007/bf02991043

Cited by 66 publications

(26 citation statements)

References 7 publications

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“…[18][19][20][21] Borba et al 20 accomplished As measurements between 1997 and 1998 in Iron Quadrangle area and obtained concentrations higher than 1000 µg g -1 in sediments from the Velhas River. Deschamps et al 18,21 studied the same area and found values up to 3300 µg g -1 between 1998 and 2003. According to CONAMA, 16 the legal limit of As at level 1 is 5.9 µg g -1 .…”

Section: Introductionmentioning

confidence: 99%

Arsenic and Mercury mobility in brazilian sediments from the São Francisco River Basin

Rezende¹,

Moura²,

Durão³

et al. 2011

J. Braz. Chem. Soc.

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Os sedimentos possuem propriedades de acumulação de poluentes e a determinação de elementos tóxicos nessas amostras permite avaliar o seu ciclo geoquímico. Arsênio e mercúrio foram determinados em 28 amostras de sedimento da Bacia do Rio São Francisco, Minas Gerais, Brasil, por geração de hidretos acoplada à espectrometria de absorção atômica (HG AAS). Foram empregados procedimentos de digestão pseudo-total empregando HCl:HNO 3 (3:1 v/v) e extração parcial com HCl 1 mol L -1 . Realizou-se ainda a determinação de Hg nas amostras sólidas, utilizando-se um analisador direto de mercúrio. Observou-se que 46% das amostras apresentaram concentrações de As acima do limite de nível 1 estabelecido pela Resolução 344/2004 do CONAMA e que 14% excederam o limite de nível 1 para Hg. As amostras com altas concentrações de Hg foram também analisadas por termodessorção acoplada à espectrometria de absorção atômica (TDAAS) para especiação e os termogramas apontaram somente a presença da espécie Hg(II).Sediments have metal accumulation properties, then, an evaluation of their geochemistry cycle is feasible via toxic element determination of these samples. Arsenic and mercury determinations were accomplished in 28 sediment samples from the São Francisco River Basin, Minas Gerais, Brazil. For sample pretreatment were employed a pseudo-total digestion procedure with HCl:HNO 3 (3:1 v/v) and a partial extraction procedure with 1 mol L -1 HCl. Arsenic and mercury were analysed by hydride generator atomic absorption spectrometry (HG AAS). Mercury determination was realized in the solid samples by direct mercury analyzer (DMA). It was observed that 46% of the samples presented arsenic concentrations above Brazil's legal limits, and 14% of samples exceeded the established mercury limit. The samples with high mercury content were also analysed by thermodesorption coupled to atomic absorption spectrometry (TDAAS) and only Hg(II) was identified.Keywords: arsenic, mercury, sediment samples, environmental monitoring, São Francisco River IntroductionIn most aquatic environments, dissolved metal concentrations in overlying water are low due to the precipitation of solids or the adsorption of suspended particles and the deposition of these particles as sediments. 1 Sediment is a matrix comprising inorganic and organic particles. It is relatively heterogeneous in terms of its physical, chemical, and biological characteristics. Sediments have an important role in the transport and storage of contaminants, being of high relevance in the identification of contaminant sources and in the determination of dispersion pathways. Sediment quality determines the biodiversity and the ecological health in aquatic systems as well as being economically important in the environmental assessment of coastal areas. 2 São Francisco is the third largest hydrographic basin in Brazil. It is responsible for drainage of a 640.000 km² area, corresponding to 8% of land in the country of Brazil. About 40% of the basin is located in the state of Minas Gerais and it is divided ...

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Section: Introductionmentioning

confidence: 99%

Arsenic and Mercury mobility in brazilian sediments from the São Francisco River Basin

Rezende¹,

Moura²,

Durão³

et al. 2011

J. Braz. Chem. Soc.

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“…Several studies have shown a positive correlation between clay and metal(loid) contents of soils (Chung and Sa, 2001;Deschamps et al, 2002;Fontes and Gomes, 2003;Kabata-Pendias, 2010). However, the predominance of kaolin minerals with minimal substitution of structural cations (88 to 96 % of the clay fraction) in Amazon 'Yellow' Haplic Ferralsols (Corrêa et al, 2008) would promote a relatively weak and limited pH-independent exchange capacity.…”

Section: Discussionmentioning

confidence: 99%

Geochemical Signature of Amazon Tropical Rainforest Soils

Souza

Fontes

Gilkes

et al. 2018

Rev. Bras. Ciênc. Solo

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Evaluating soil geochemical diversity in the Amazon Basin has been a challenge largely because most study sites have been at the edge of the basin and it is difficult to get samples in such a region. Here we show that even among the most weathered soils, physicochemical soil properties express lithology. Our results are based on topsoil samples collected from different locations in minimally disturbed areas in the state of Amazonas, Brazil. Soil properties were measured using methods which are suitable for highly developed soils. The Chemical Index Alteration and Weathering Index of Parker was calculated based on the content of metal(loid)s in soils determined by X-ray fluorescence. Descriptive statistics, Pearson correlation, and Principal Component Analysis (PCA) were performed on data. In general, Amazon rainforest soils are more deeply weathered than soils in other Brazilian biomes and tropical rainforests in Asia and Africa. The high coefficient of variation of metal(loid) contents express pedogenesis and parent material diversity. Correlation analysis indicated that the tri-pentavalent elements are strongly associated with Al and Fe contents in the topsoil. In contrast, mono-divalent elements are correlated with sand and silt fractions. According to PCA, five soil groups with defined geochemical compositions and degrees of weathering could be identified: i) acidic sandy podzolized soils; ii) acidic loamy ferralitic soils with the highest content of tri-pentavalent ions; iii) acidic clayey kaolinitic soils with low metal(loid) contents; iv) acidic loamy kaolinitic soils with low metal(loid) contents; and v) silty neutral 2:1 clay soils. This study is the first effort to analyze the geochemical diversity in Amazon rainforest soils. These data are extremely valuable in determining the geochemical background for these soil types and this region. Geochemical variability can be predicted to some extent by lithology and pedogenesis, which can be applied to define the sampling required in future studies.

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“…As históricas atividades de mineração desenvolvidas na região têm sido responsáveis pela liberação de grandes quantidades de As para ambientes aquáticos e terrestres. Elevados teores de As têm sido registrados em água, solos e sedimentos desta região, relacionados tanto à litologia local quanto ao descarte de rejeitos proveniente das atividades de mineração (Matschullat et al, 2000;Deschamps et al, 2002;Borba et al, 2003;Mello et al, 2006;Gonçalves et al, 2007).…”

Section: Amostras De Sedimentosunclassified

Otimização das condições de pré-redução do As(V) em extratos do método BCR para quantificação de arsênio por HG-AAS

Varejão

Bellato²,

Mello³

et al. 2009

Rev. Bras. Ciênc. Solo

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(5) RESUMO A determinação de As por espectrometria de absorção atômica com geração de hidretos (HG-AAS) constitui um método simples, sensível, preciso e de baixo custo. Entretanto, essa técnica requer a pré-redução das espécies de As(V), o que se obtém através do uso de agentes redutores como o KI. Em extratos contendo agentes oxidantes, a pré-redução do As é comprometida, como acontece em extratos obtidos pela aplicação do método BCR (acrônimo francês para Community Bureau of Reference) para a extração sequencial de As em sedimentos. O objetivo deste trabalho foi avaliar as condições de redução do As(V) a As(III), de modo a permitir o uso da HG-AAS para a quantificação do arsênio em extratos obtidos a partir do método BCR. Foram avaliadas condições reacionais utilizando KI, L-cisteína e ácido ascórbico. Para cada uma das etapas de extração do método BCR, diferentes condições de pré-redução possibilitaram a detecção quantitativa do As presente. O uso do método BCR para a extração de arsênio em amostras de sedimentos contaminadas e a aplicação das condições de pré-redução do As(V) selecionadas, seguida pela detecção por HG-AAS, forneceram percentagens de recuperação entre 91 e 99 %.

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Soil and sediment geochemistry of the iron quadrangle, Brazil the case of arsenic

Cited by 66 publications

References 7 publications

Arsenic and Mercury mobility in brazilian sediments from the São Francisco River Basin

Arsenic and Mercury mobility in brazilian sediments from the São Francisco River Basin

Geochemical Signature of Amazon Tropical Rainforest Soils

Otimização das condições de pré-redução do As(V) em extratos do método BCR para quantificação de arsênio por HG-AAS

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