Consulta: creatorFacets:"Riso, Ricardo D."
Registros recuperados: 4
Data/hora: 16/06/2024 19:51:41

A comparison of in situ vs. ex situ filtration methods on the assessment of dissolved and particulate metals at hydrothermal vents
Provedor de dados: 5
Autores: Cotte, Laura; Waeles, Mathieu; Pernet-coudrier, Benoit; Sarradin, Pierre-marie; Cathalot, Cecile; Riso, Ricardo D.
The objective of this study was to assess the impact of the filtration method (in situ vs. ex situ) on the dissolved/particulate partitioning of 12 elements in hydrothermal samples collected from the Lucky Strike vent field (Mid-Atlantic Ridge; MAR). To do so, dissolved ( &lt;0.45 mu m) and particulate Mg, Li, Mn, U, V, As, Ba, Fe, Zn, Cd, Pb and Cu were measured using different techniques (HR-ICP-MS, ICP-AES and CCSA). Using in situ filtration as a baseline, we showed that ex situ filtration (on-board and on shore after freezing) resulted in an underestimation of the dissolved pool, which was counterbalanced by an overestimation of the particulate pool for almost all the elements studied. We also showed that on-board filtration was acceptable for the...
Tipo: Text
Palavras-chave: Metal; Hydrothermal vent; Dissolved; Particulate; Filtration method.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00298/40970/42656.pdf

Sulfide determination in hydrothermal seawater samples using a vibrating gold micro-wire electrode in conjunction with stripping chronopotentiometry
Provedor de dados: 5
Autores: Aumond, Virginie; Waeles, Mathieu; Salaun, Pascal; Gibbon-walsh, Kristoff; Van Den Berg, Constant M. G.; Sarradin, Pierre-marie; Riso, Ricardo D.
A rapid electrochemical stripping chronopotentiometric procedure to determined sulfide in unaltered hydrothermal seawater samples is presented. Sulfide is deposited at -0.25 V (vs Ag/AgCl, KCl 3 M) at a vibrating gold microwire and then stripped through the application of a reductive constant current (typically -2 mu A). The hydrodynamic conditions are modulated by vibration allowing a short deposition step, which is shown here to be necessary to minimize H2S volatilization. The limit of detection (LOD) is 30 nM after a deposition step of 7s. This LOD is in the same range as the most sensitive cathodic voltammetric technique using a mercury drop electrode and is well below those reported previously for other electrodes capable of being implemented in situ....
Tipo: Text
Palavras-chave: Sulfide; Stripping chronopotentiometry; Vibrating electrode; Gold; Seawater; Hydrothermal.
Ano: 2012
URL: http://archimer.ifremer.fr/doc/00111/22222/20065.pdf

On the nature of dissolved copper ligands in the early buoyant plume of hydrothermal vents
Provedor de dados: 5
Autores: Cotte, Laura; Omanovic, Dario; Waeles, Mathieu; Laes, Agathe; Cathalot, Cecile; Sarradin, Pierre-marie; Riso, Ricardo D.
Environmental contextCopper released by deep-sea hydrothermal vents has been recognised to be partly stabilised against precipitation by its complexation with strong Cu binding ligands. Yet, the sources and nature of these compounds in such environments are still not fully understood. This study shows that the Cu ligands detected are hydrothermally sourced and could be mainly inorganic sulfur species. AbstractThe apparent speciation of Cu in the early buoyant plume of two black smokers (Aisics and Y3) from the hydrothermal vent field Lucky Strike (Mid-Atlantic Ridge) was investigated using competitive ligand exchange-adsorptive cathodic stripping voltammetry (CLE-AdCSV). We have assessed the apparent Cu-binding ligand concentration ([L]) and the...
Tipo: Text
Ano: 2018
URL: https://archimer.ifremer.fr/doc/00444/55558/57208.pdf

Cadmium in the waters off South Morocco: Nature of particles hosting Cd and insights into the mechanisms fractionating Cd from phosphate
Provedor de dados: 5
Autores: Waeles, Mathieu; Planquette, Helene; Afandi, Imane; Delebecque, Nina; Bouthir, Fatimazohra; Donval, Anne; Shelley, Rachel U.; Auger, Pierre-amael; Riso, Ricardo D.; De Morais, Luis Tito.
In this study, we report the distributions of total dissolvable cadmium and particulate cadmium from 27 stations in southern Moroccan coastal waters (22°N–30°N), which is part of the North-West African upwelling system. These distributions were predominantly controlled by upwelling of the North Atlantic Central Waters (NACWs) and uptake by primary production. Atmospheric inputs and phosphogypsum slurry inputs from the phosphate industry at Jorf Lasfar (33°N), recently estimated as an important source of dissolved cadmium (240 t Cd yr−1), are at best of minor importance for the studied waters. Our study provides new insights into the mechanisms fractionating cadmium from phosphate. In the upper 30 m, the anomalies observed in terms of Cd:P ratios in both...
Tipo: Text
Ano: 2016
URL: https://archimer.ifremer.fr/doc/00334/44520/44216.pdf