Please use this identifier to cite or link to this item: http://repositorio.ufc.br/handle/riufc/67915
Type: Artigo de Periódico
Title: Mercury distribution and reactivity in waters of a subtropical coastal lagoon, Sepetiba Bay, SE Brazil
Authors: Lacerda, Luiz Drude de
Marins, Rozane Valente
Paraquetti, Heloisa Helena Moreira
Mounier, Stephane
Benaim, Jean
Fevrier, Dominique
Keywords: Heavy metals - Mercury;Mercury Distribution;Dissolved Organic Carbon (DOC);Metais pesados - Mercúrio;Mercúrio - Distribuição;Carbono Orgânico Dissolvido (COD)
Issue Date: 2001
Publisher: Journal of the Brazilian Chemical Society
Citation: LACERDA, L. D.; Marins, Rozane V.; PARAQUETTI, H. H. M.; MOUNIER, S.; BENAIM, J. Mercury distribution and reactivity in waters of a subtropical coastal lagoon, Sepetiba Bay, SE Brazil. Journal of the Brazilian Chemical Society, São Paulo, v. 12, n.1, p. 93-98, 2001.
Abstract in Brazilian Portuguese: As concentrações de Hg total e reativo, de carbono orgânico dissolvido (COD) e carbono orgânico particulado (COP) foram medidas em diferentes massas d’água na Baía de Sepetiba, SE do Brasil, com o objetivo de avaliar mudanças na reatividade do Hg ao longo do gradiente estuarino. As concentrações de Hg reativo foram mais baixas em águas da baía franca (0,09 ± 0,06 ng L-1), seguidas pelas águas influenciadas por rios (0,19 ± 0,06 ng L-1), e pelas de manguezais (0,29 ± 0,02 ng L-1). As concentrações de Hg total foram menores em águas da baía franca (0,38 ± 0,20 ng L-1), seguidas pelas águas de manguezais (0,56 ± 0,01 ng L-1), e foram maiores nas águas influenciadas por rios (0,99 ± 0,29 ng L-1). O percentual de Hg reativo em relação à concentração total foi menor nas águas influenciadas por rios (20,7%), seguidas pelas de águas da baía franca (31,2%), e foram maiores nas águas de manguezais (53,2%). O percentual de Hg reativo em relação à concentração total apresentou significativa correlação inversa com as concentrações de Hg total. Nenhuma correlação significativa foi encontrada entre as concentrações de Hg e a salinidade, o COP e o pH. Entretanto, as concentrações de Hg reativo apresentaram uma correlação positiva, significativa com o COD, mostrando que o controle da reatividade do Hg e, eventualmente, de sua biodisponibilidade na Baía de Sepetiba, deve-se principalmente a formação de complexos com a matéria orgânica dissolvida. A survey of the reactive and total Hg concentrations in surface waters and of the quantity of particulate organic carbon (POC) and dissolved organic carbon (DOC), were performed along a transect from the major rivers mouths and mangrove dominated areas to the open bay waters of Sepetiba Bay, SE Brazil. The objective of the survey was to evaluate changes in Hg reactivity during the transport along the estuarine gradient. Reactive Hg concentrations were lowest in open bay waters, (0.09 ± 0.06 ng L-1), followed by river influenced waters (0.19 ± 0.06 ng L-1), and mangrove (0.29 ± 0.02 ng L-1). Total Hg concentrations were lowest in open bay (0.38 ± 0.20 ng L-1), followed by mangrove waters (0.56 ± 0.01 ng L-1), and river influenced waters (0.99 ± 0.29 ng L-1). The percentages of reactive Hg relative to the total Hg concentrations were lowest in river influenced waters, (20.7%), followed by open bay waters (31.2%), and mangrove waters (53.2%). The percent of reactive Hg to the total Hg concentrations showed a significant negative correlation with the total Hg concentrations following a potential equation. No relationship between reactive Hg concentrations and POC, salinity or pH were found, however, reactive Hg correlates significantly with DOC, suggesting that organo-complexes, rather than chloro-complexes, are the major controllers of Hg reactivity, and eventually bioavailability in Sepetiba Bay.
Abstract: A survey of the reactive and total Hg concentrations in surface waters and of the quantity of particulate organic carbon (POC) and dissolved organic carbon (DOC), were performed along a transect from the major rivers mouths and mangrove dominated areas to the open bay waters of Sepetiba Bay, SE Brazil. The objective of the survey was to evaluate changes in Hg reactivity during the transport along the estuarine gradient. Reactive Hg concentrations were lowest in open bay waters, (0.09 ± 0.06 ng L-1), followed by river influenced waters (0.19 ± 0.06 ng L-1), and mangrove (0.29 ± 0.02 ng L-1). Total Hg concentrations were lowest in open bay (0.38 ± 0.20 ng L-1), followed by mangrove waters (0.56 ± 0.01 ng L-1), and river influenced waters (0.99 ± 0.29 ng L-1). The percentages of reactive Hg relative to the total Hg concentrations were lowest in river influenced waters, (20.7%), followed by open bay waters (31.2%), and mangrove waters (53.2%). The percent of reactive Hg to the total Hg concentrations showed a significant negative correlation with the total Hg concentrations following a potential equation. No relationship between reactive Hg concentrations and POC, salinity or pH were found, however, reactive Hg correlates significantly with DOC, suggesting that organo-complexes, rather than chloro-complexes, are the major controllers of Hg reactivity, and eventually bioavailability in Sepetiba Bay.
URI: http://www.repositorio.ufc.br/handle/riufc/67915
ISSN: 0103-5053
Appears in Collections:LABOMAR - Artigos publicados em revistas científicas

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