nieuwe zoekopdracht
[ meld een fout in dit record ]mandje (0): toevoegen | toon Print deze pagina

Coprecipitation of phosphate and silicate affects environmental iron (oxyhydr)oxide transformations: A gel-based diffusive sampler approach
Kraal, P.; van Genuchten, C.M.; Lenstra, W.K.; Behrends, T (2020). Coprecipitation of phosphate and silicate affects environmental iron (oxyhydr)oxide transformations: A gel-based diffusive sampler approach. Environ. Sci. Technol. 54(19): 12795-12802. https://dx.doi.org/10.1021/acs.est.0c02352
In: Environmental Science and Technology. American Chemical Society: Easton. ISSN 0013-936X; e-ISSN 1520-5851, meer
Peer reviewed article  

Beschikbaar in  Auteurs 

Author keywords
    ferrihydrite; lepidocrocite; crystallization; sulfidation; DGT-DET; eutrophication

Auteurs  Top 
  • Kraal, P., meer
  • van Genuchten, C.M.
  • Lenstra, W.K.
  • Behrends, T

Abstract
    Sorption of nutrients such as phosphate (P) and silicate (Si) by ferric iron (oxyhydr)oxides (FeOx) modulates nutrient mobility and alters the structure and reactivity of the FeOx. We investigated the impact of these interactions on FeOx transformations using a novel approach with samplers containing synthetic FeOx embedded in diffusive hydrogels. The FeOx were prepared by Fe(III) hydrolysis and Fe(II) oxidation, in the absence and presence of P or Si. Coprecipitation of P or Si during synthesis altered the structure of Fe precipitates and, in the case of Fe(II) oxidation, lepidocrocite was (partly) substituted by poorly ordered FeOx. The pure and P- or Si-bearing FeOx were deployed in (i) freshwater sediment rich in dissolved Fe(II) and P and (ii) marine sediment with sulfidic pore water. Iron(II)-catalyzed crystallization of poorly ordered FeOx was negligible, likely due to surface passivation by adsorption of dissolved P. Reaction with dissolved sulfide was modulated by diffusion limitations and therefore the extent of sulfidation was the lowest for poorly ordered FeOx with high reactivity toward sulfide that created temporary, local sulfide depletion (Fh < Lp). We show that coprecipitation-induced changes in the FeOx structure affect coupled iron-nutrient cycling in aquatic ecosystems. The gel-based method enriches our geochemical toolbox by enabling detailed characterization of target phases under natural conditions.

Alle informatie in het Integrated Marine Information System (IMIS) valt onder het VLIZ Privacy beleid Top | Auteurs 
IMIS is ontwikkeld en wordt gehost door het VLIZ, voor meer informatie contacteer .