IMIS | Vlaams Instituut voor de Zee
 

Vlaams Instituut voor de Zee

Platform voor marien onderzoek

IMIS

Publicaties | Instituten | Personen | Datasets | Projecten | Kaarten
[ meld een fout in dit record ]mandje (0): toevoegen | toon Print deze pagina

The post-depositional reactivity of iron and manganese in the sediments of a macrotidal estuarine system
Ouddane, B.; Boust, D.; Martin, E.; Fischer, J.-C.; Wartel, M. (2001). The post-depositional reactivity of iron and manganese in the sediments of a macrotidal estuarine system. Estuaries 24(6): 1015-1028. http://dx.doi.org/10.2307/1353014
In: Estuaries. The Estuarine Research Federation, Chesapeake Biological Laboratory: Columbia, S.C., etc.,. ISSN 0160-8347; e-ISSN 1559-2758, meer
Peer reviewed article  

Beschikbaar in  Auteurs 

Auteurs  Top 
  • Ouddane, B., meer
  • Boust, D.
  • Martin, E.

Abstract
    Four cores of anoxic sediments were collected from the Seine estuary to assess the early diagenesis pathways leading to the formation of previously reactive phase. Pore waters were analyzed for dissolved iron (Fe) and manganese (Mn) and different ligands (e.g., sulfate, chloride, total inorganic carbon). The anoxic zone is present up to the first centimeter depth, in these conditions the reduction of Mn and Fe oxides and SO42− was verified. The sulfate reduction was well established with a subsequent carbon mineralization in the NORMAI94 core. The chemical speciation of Mn and Fe in the dissolved and solid phases was determined. For the dissolved phase, thermodynamic calculations were used to characterize and illustrate the importance of carbonate and phosphate phases as sinks for Fe and Mn. The ion activity product (IAP) of Fe and Mn species was compared to the solubility products (Ks) of these species. In the solid phase, the presence of higher concentration of calcium carbonate in the Seine sediments is an important factor controlling Mn cycle. The carbonate-bound Mn can reach more than 75% of the total concentration. This result is confirmed by the use of electron spin resonance (ESR) spectroscopy. The reduction of Fe is closely coupled to the sulfate reduction by the formation of new solid phases such as FeS and FeS2, which can be regarded as temporal sinks for sulfides. These forms were quantified in all cores as acid volatile sulfide (AVS: FeS+ free sulfide) and chromium reducible sulfide (CRS: FeS2+elemental sulfur S0).

Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid Top | Auteurs