Alternativa analítica para especiação físico-química de mercúrio em águas costeiras tropicais

Marins, Rozane Valente; Paraquetti, Heloisa H. M.; Ayres, Gisele Antunes

doi:10.1590/s0100-40422002000300007

Cited by 18 publications

(17 citation statements)

References 13 publications

(21 reference statements)

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“…51,54,[59][60][61][62][63] This fraction was always higher during the ebb tide (1.7 ± 0.8 ng L -1 , n = 40 and 3.5 ± 0.9 ng L -1 , n = 21 in dry and wet season respectively) than during the flood tide (0.7 ± 0.5 ng L -1 , n = 24 and 2.4 ± 0.8 ng L -1 , n = 23 in dry and wet season respectively) (Figure 3c). The average non-reactive Hg fraction during the dry season (1.3 ± 0.9 ng L -1 , n = 64) was lower than during the wet season (3.0 ± 1.0 ng L -1 , n = 44).…”

Section: Mercury Speciationmentioning

confidence: 99%

“…This was followed by a reduction with the same SnCl 2 solution used for reducing the reactive Hg fraction. 51,53,54 Total Hg includes all dissolved Hg species strongly bound to soluble inorganic and organic complexes, and probably some of the Hg weakly bound to suspended particles according to Bloom and Crecelius, 51 Marins et al 54 and EPA. 53 A recent study in Sepetiba Bay 44 shows that the total Hg extracted with bromine monochloride solution roughly correspond the dissolved Hg fraction due to low SPM concentrations.…”

Section: Mercury Analysismentioning

confidence: 99%

“…54,[59][60][61] Since the sample oxidation with bromine monochloride solution (BrCl) is sufficient to cleave C-Hg covalent bonds of the very stable organic-Hg complexes and liberate Hg +2 for reduction as part of the sparging step. 51,54,[59][60][61][62][63] Particulate Hg fraction was determined after the filtration of the non-acidified sub-samples through a glass micro fiber filter (0.70 µm, Whatman GF/F) pretreated by heating at 450 °C for 12 h, directly after sampling. The filters were analyzed by oxidation with a 50% (v/v) aqua-regia solution (4H 2 O:3HCl:1HNO 3 ), at 70 to 80 °C for 1 h followed by a reduction with the same SnCl 2 solution used for reducing the reactive Hg fraction.…”

Section: Mercury Analysismentioning

confidence: 99%

“…Mercury determination was performed at a wavelength of 253.7 nm, in a Tekran Model 2500 Cold Vapor Atomic Fluorescence Spectrophotometer. 42,54,56,64 Under the operational conditions described, the analytical detection limit of the method was 1.0 pg, based on the ratio between three standard deviation estimated by S y/x (S y/x = {(y i -y) 2 (n-2) -1 } 1/2 ), where the axis x and y were done in mass (ng Hg) and fluorescence intensity, respectively and the slope of the regression line of the calibration curve. 65 All samples were analyzed in duplicate.…”

Section: Mercury Analysismentioning

confidence: 99%

“…The use of purge in two cycles of 2 min to elemental Hg determinations present more satisfactory results than the use of 4 min of purge in this analytical systems. 54 Reactive Hg was analyzed in non-acidified subsamples (20 mL) after the addition of an acidic (1% (v/v) distillated HCl + 1% (m/v) ascorbic acid) 10% SnCl 2 solution. This fraction includes mostly ionic (Hg 2+ ) plus elemental Hg, but also the Hg fraction weakly bound to inorganic and organic complexes.…”

mentioning

confidence: 99%

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Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Paraquetti¹,

Lacerda²,

Almeida³

et al. 2007

J. Braz. Chem. Soc.

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Este estudo descreve as mudanças na especiação de Hg nas águas da Baía de Sepetiba, SE, Brasil, ao longo do gradiente estuarino, durante eventos de maré em diferentes estações. A avaliação química das águas da baía indicou uma exportação de material particulado em suspensão (MPS) pobre em carbono orgânico para a plataforma continental adjacente, principalmente durante a estação chuvosa e uma importação de MPS oceânico rico em carbono orgânico, provavelmente de origem fitoplanctônica, durante a estação seca. A especiação química do Hg demonstrou que a produção de Hg 0 na Baía de Sepetiba pode ser controlada pela produtividade primária, e que a baía atua como produtora e exportadora de formas orgânicas de Hg para as áreas adjacentes, já que as maiores concentrações de Hg não-reativo foram encontradas durante a maré vazante. Não foram observadas correlações significantes entre as concentrações de Hg não-reativo e carbono orgânico dissolvido ou particulado. Em geral, as frações de Hg particulado, Hg não-reativo e Hg reativo representam 55%, 35% e 9,5% do conteúdo total de Hg nas águas da Baía de Sepetiba, respectivamente.This work describes changes in Hg speciation in water along the transport from Sepetiba Bay, SE Brazil, to the adjacent continental platform during tide events and in different seasons. The chemical evaluation of Sepetiba Bay waters showed that the bay exports suspended particulate material (SPM) impoverish in organic carbon to adjacent continental platform areas, mainly during the wet season and imports SPM enriched in organic carbon from the ocean, probably of phytoplanktonic origin, during the dry season. The chemical speciation of Hg during the study period showed that Hg 0 production can be controlled by primary productivity and that the bay acts as a producer and exporter of organic species of Hg to adjacent areas, since the highest non-reactive Hg concentrations were observed during the ebb tide. No significant correlations were found between non-reactive Hg and dissolved or particulate organic matter concentrations. In general the particulate Hg, non-reactive Hg and reactive Hg fractions represents 55%, 35.5% and 9.5% of the total Hg content in Sepetiba Bay waters, respectively.Keywords: mercury speciation, coastal area, organic carbon, Sepetiba Bay IntroductionCoastal environments are complex and very dynamic systems showing a strong salinity gradient, high variation of suspended matter concentration and complex hydrodynamic processes. They act as links between the terrestrial and oceanic environments, present a large capacity to accumulate materials of continental and marine origin and are strongly affected by tidal events and continental hydrology. These environments are also characterized by land-sea gradients of physicochemical processes such as oxidation/reduction, sorption/desorption and precipitation/dissolution, which result in gradients of dissolved chemical species concentration, ionic force, pH and redox potential, which are responsible for the precipitation of the major part of ...

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Section: Mercury Speciationmentioning

confidence: 99%

Section: Mercury Analysismentioning

confidence: 99%

Section: Mercury Analysismentioning

confidence: 99%

Section: Mercury Analysismentioning

confidence: 99%

mentioning

confidence: 99%

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Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Paraquetti¹,

Lacerda²,

Almeida³

et al. 2007

J. Braz. Chem. Soc.

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Mercury Emission Factors from Intensive Shrimp Aquaculture and Their Relative Importance to the Jaguaribe River Estuary, NE Brazil

Lacerda

Soares

Costa

et al. 2011

Bull Environ Contam Toxicol

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This study estimated Hg emission factors (EFs) and total Hg loading to the Jaguaribe Estuary, NE Brazil, from intensive shrimp farming, and compares this with other local anthropogenic activities. The EF reached 83.5 mg ha(-1) cycle(-1) (about 175 mg ha(-1) year(-1)), resulting in an annual Hg load to the estuary of 0.35 kg. The calculated EF is comparable to Hg EFs from urban wastewaters (200 mg ha(-1)) and solid waste disposal (400 mg ha(-1) year(-1)) from cities located in the estuary's basin. However, due to the smaller area of aquaculture (2,010 ha), total annual loads are much lower than from these other sources (75 and 150 kg year(-1), respectively). Since shrimp farming effluents are released directly into the estuary, the estimated high EF raises environmental concerns with this expanding industry, suggesting the inclusion of this element in ongoing environmental monitoring programs.

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Mercury Distribution in a Mangrove Tidal Creek Affected by Intensive Shrimp Farming

Costa

Soares

Torres

et al. 2013

Bull Environ Contam Toxicol

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In this study, the Hg distributions in water and sediments from a mangrove creek that receives intensive shrimp farming effluents were determined. The average dissolved and particulate Hg concentrations in the water varied from 3.1 to 9.2 ng L(-1) and from 4.4 to 9.4 ng L(-1), respectively. However, the Hg concentrations in the suspended particulate matter and the bottom sediments varied from 95.4 to 115.7 ng g(-1) and from 1.6 to 10.3 ng g(-1), respectively. A Ward quadratic distance cluster analysis based on the Hg concentrations and hydro- and geochemical parameters (oxygen, salinity, temperature, pH, and organic matter and aluminum content) showed the effects of shrimp farming effluents on the Hg distribution pattern. Furthermore, these results were supported by the Hg distribution in the sediment cores. This study emphasizes the necessity of including Hg as a potential pollutant when monitoring the environmental impacts of intensive shrimp farming.

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Alternativa analítica para especiação físico-química de mercúrio em águas costeiras tropicais

Cited by 18 publications

References 13 publications

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Mercury speciation changes in waters of the sepetiba Bay, SE Brazil during tidal events and different seasons

Mercury Emission Factors from Intensive Shrimp Aquaculture and Their Relative Importance to the Jaguaribe River Estuary, NE Brazil

Mercury Distribution in a Mangrove Tidal Creek Affected by Intensive Shrimp Farming

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