Distribution of dissolved iron in sediment pore waters at submillimetre resolution

Davison, William; Grime, G.W.; Morgan, J. Alun W.; Clarke, Ken J.

doi:10.1038/352323a0

Cited by 175 publications

(102 citation statements)

References 13 publications

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“…Finally, the area around the cham- bers was covered with ceramic tiles to minimize the risk that burrowing could re-ventilate the chambers. In every chamber, a series of 8 DET (Diffusive Equilibrium in Thin films) gel probes (Davison et al, 1991;Fones et al, 1998;Metzger et al, 2007) was inserted 24 to 48 h before termination of the experiment, allowing in situ sampling of pore water at a 2 mm resolution (see below, Fig. 6d).…”

Section: Methodsmentioning

confidence: 99%

Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic

et al. 2014

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Abstract. Long-term experimental studies suggest that, under transient anoxic conditions, redox fronts within the sediment shift upwards, causing sequential rise and fall of benthic fluxes of reduced species (Mn(II), Fe(II) and S(-II)). Infaunal benthic organisms are associated with different redox fronts as micro-habitats and must be affected by such changes during natural hypoxia events. In order to document the geochemical evolution of the sediment during prolonged anoxia in the framework of an in situ experiment designed to mimic natural conditions, benthic chambers were deployed on the seafloor of the Northern Adriatic and sampled after 9, 30 and 315 days of incubation. Oxygen and sulfide were measured continuously in the early stages (9 days) of the experiment. High-resolution pore water profiles were sampled by DET probes and redox-sensitive species (S(VI), Mn(II) and Fe(II)) and alkalinity were measured.Starting oxygen saturation was about 80 % within the chamber. After 7 days, anoxia was established in the bottom waters within the chambers. Mn(II) and Fe(II) started diffusing towards the anoxic water column until they reached the surficial sediment. Being reoxidized there, Mn and Fe reprecipitated, giving a rusty coloration to the seafloor. Infaunal species appeared at the sediment surface. After 20 days, all macro-organisms were dead. Decomposition of macroorganisms at the sediment-water interface generated S(-II) within the entire height of the chamber, leading to a downward flux of sulfides into the sediment, where they were quickly oxidized by metallic oxides or precipitated as FeS. S(-II) was below detection in the water column and pore waters at the end of the experiment. Our results suggest that S(-II) enrichment in the water column of coastal systems, which are episodically anoxic, is strongly controlled by the biomass of benthic macrofauna and its decay during anoxia, whereas its residence time in the water column is controlled by iron availability (as solid oxides or as dissolved reduced cations) within the sediment, even without water circulation.

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Section: Methodsmentioning

confidence: 99%

Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic

et al. 2014

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“…The recently developed technique of diffusive equilibrium in thin films known as DET (Davison et al, 1991) is similar to dialysis, but the sampling medium is a hydrogel instead of a solution retained by a dialysis membrane. As for dialysis, solutes equilibrate within the solution held in the sampler (the hydrogel is typically 95% water).…”

Section: Introductionmentioning

confidence: 99%

“…In recent years techniques such as DET (Diffusive Equilibrium in Thin Films) and DGT (Diffusive Gradients in Thin Films) have become increasingly popular for the determination of trace metals, major ions and nutrients in sediment pore water (Davison et al, 1991;Docekalova et al, 2002;Fones et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Determination of High Resolution Pore Water Profiles of Trace Metals in Sediments of the Rupel River (Belgium) using Det (Diffusive Equilibrium in Thin Films) and DGT (Diffusive Gradients in Thin Films) Techniques

Leermakers

Gao

Gabelle

et al. 2005

Water Air Soil Pollut

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Abstract. The techniques of diffusional equilibrium in thin films (DET) and diffusional gradients in thin films (DGT) were used to obtain high resolution pore water profiles of total dissolved and labile trace (mobilizable) metals in the sediments of the Rupel River, Belgium. DGT measures labile metal species in situ by immobilizing them on a resin gel after diffusion through a diffusive gel whereas for DET an equilibrium is established between the DET gel and the pore water. Concentrations of Pb and Zn obtained by DGT were in good agreement with the results obtained by centrifugation, and thus were well buffered by rapid equilibrium with the solid phase, whereas Fe, Mn and Cd were very tightly bound to the sediment phase and large differences were observed between the labile and the total metal concentrations. Cu, Zn, Co and Ni show intermediated behavior.Good correlations were found between the profiles of As and Fe and Mn and Co for DET as well as DGT showing a close link between the geochemical behavior of these elements. Cu, Zn, Pb and Cd are also influenced by the reductive mobilization of Fe and Mn oxides but are also closely linked to the bacterial degradation of organic matter in the surface sediments as to the precipitation of metal sulfides in the deeper layers.

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“…Their solubility depends on the solvent characteristics and the solubility constant for each elements, which determines its proportionality and abundance. These can be studied both in the water column and in interstitial waters (Davison et al, 1991(Davison et al, , 1994(Davison et al, , 1997(Davison et al, , 2000Zhang & Davison, 1995;Fones et al, 1998;Pizarro et al, 2001).…”

Section: Sea Water Contains Low Concentrations (µG Lmentioning

confidence: 99%

Dissolved trace metals in the water column of Reloncavi Fjord, Chile

Ahumada

Rudolph

Gonzalez

et al. 2011

lajar

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ABSTRACT.We analyzed the concentration of dissolved trace metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb) in the water column of Reloncaví Fjord. Sampling was performed during the CIMAR 12 Fiordos cruise in 2006. A total of 36 passive samplers or DGTs (diffusion gradient in thin films) were anchored at four stations along the longitudinal axis of the fjord. The DGTs were deployed at three depths per station and left there for 48 h. The metal contents on each thin film were analyzed using inductively coupled plasma atomic emission spectroscopy. Concentrations were highest in the surface layer at the head of the estuary, which is directly influenced by Petrohué River. Characteristic sequences of the studied metals were defined in the area with the greatest continental influence (Z (5-25 m) = Cu >Mn> Fe > Ni >Pb> Cr > Cd > Co) and in the area with a marine or coastal influence (Z (5-25 m) = Fe > Cu>Mn> Ni >Pb> Cr > Cd > Co). A similar metal sequence was found in the deepest layer: Z (40 m) = Fe >Mn> Cu >Pb> Ni > Cd > Cr > Co. The passive sampling technique using DGTs to determine dissolved trace metals in the sea water provided robust information on the concentrations of the ten metals analyzed. Keywords: dissolved metals, passive samplers, fjords, southern Chile.Metales trazas disueltos en la columna de agua en el fiordo Reloncaví, Chile RESUMEN. Se analiza la concentración de metales trazas disueltos (Cd, Co, Cr, Cu, Fe, Mn, Ni y Pb), en la columna de agua del fiordo Reloncaví. El muestreo se realizó durante la campaña CIMAR 12 Fiordos, 2006. Para ello se fondeó en cuatro estaciones y en tres profundidades, un total de 36 muestreadores pasivos o DGT (láminas de gradiente de difusión) a lo largo del eje longitudinal del fiordo, durante 48 h. El contenido de metales en cada lámina fue analizado mediante espectroscopía de emisión atómica con acoplamiento inductivo de plasma. Las mayores concentraciones se observaron en la superficie de la columna de agua, en la cabeza del estuario, directamente influenciada por el río Petrohué. Se definió para el área una secuencia de los metales estudiados característica, para la zona de mayor influencia continental: Z (5-25 m) = Cu > Mn > Fe > Ni > Pb > Cr > Cd > Co y para la zona de influencia marina o costera: Z (5-25 m) = Fe > Cu > Mn > Ni > Pb > Cr > Cd > Co, observándose una secuencia semejante para los metales analizados en la capa de mayor profundidad: Z (40 m) = Fe > Mn > Cu > Pb > Ni > Cd > Cr > Co. La técnica de muestreo pasiva, con DGTs, para la determinación de metales traza disueltos en agua de mar, permitió obtener información robusta de las concentraciones de los diez metales analizados. Palabras clave: metales disueltos, muestreadores pasivos, fiordos, sur de Chile.

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Distribution of dissolved iron in sediment pore waters at submillimetre resolution

Cited by 175 publications

References 13 publications

Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic

Artificially induced migration of redox layers in a coastal sediment from the Northern Adriatic

Determination of High Resolution Pore Water Profiles of Trace Metals in Sediments of the Rupel River (Belgium) using Det (Diffusive Equilibrium in Thin Films) and DGT (Diffusive Gradients in Thin Films) Techniques

Dissolved trace metals in the water column of Reloncavi Fjord, Chile

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