Elsevier

Water Research

Volume 31, Issue 6, June 1997, Pages 1347-1354
Water Research

Formation of iron(III) hydroxides from homogeneous solutions

https://doi.org/10.1016/S0043-1354(96)00388-0Get rights and content

Abstract

The technique of precipitation from homogeneous solutions was used in this study to simulate the formation of iron(III) hydroxides under conditions similar to those at the redox boundary of natural waters. The technique allowed the precipitation of iron(III) hydroxides to occur, while the precipitant iron(III) was generated very slowly by the oxygenation of iron(II) and, subsequently, hydrolyzed. During the precipitation, pH heterogeneity did not occur locally as was usually observed in the conventional preparation of iron(III) hydroxides in the laboratory (e.g. addition of a base to an acidic solution of iron(III). Thus, the rapid hydrolysis and the extensive polymerization of iron(III) hydroxides were effectively prevented, particularly at the early stage of the precipitation. The iron(III) precipitates formed in this way are more representative of iron(III) hydroxides occurring particularly at the redox boundary of natural waters than those formed by the conventional procedure in the laboratory. The effects of various solutes, such as H4SiO4, H2PO4 and oxalate which commonly occur in natural waters, on the composition, size and shape of the iron(III) hydroxides formed have also been studied.

References (27)

  • R.M. Cornell et al.

    Formation of goethite from ferrihydrite at physiological pH under influence of cysteine

    Polyhedron

    (1989)
  • L. Sigg et al.

    Redox conditions and alkalinity generation in a seasonal anoxic lake (Lake Greifen)

    Marine Chem.

    (1991)
  • L.S. Balistrieri et al.

    The cycling of iron and manganese in the water column of Lake Sammamish, Washington

    Limnol. Oceanogr.

    (1992)
  • R.A. Berner

    A new geochemical classification of sedimentary environments

    J. Sediment Petrol.

    (1981)
  • J. Buffle et al.

    Physico-chemical characteristics of a colloidal iron phosphate species formed at the oxic-anoxic interface of an eutrophic lake

    Geochim. Cosmochim. Acta

    (1988)
  • J. Buffle et al.
  • L.S. Clesceri et al.

    Standard Methods For the Examination of Water and Waste Water

  • R.M. Cornell et al.

    Review of the hydrolysis of iron(III) and the crystallization of amorphous iron(III) hydroxide hydrate

    J. Chem. Technol. Biotechnol.

    (1989)
  • R.M. Cornell et al.

    Iron Oxides in the Laboratory

    (1991)
  • W. Davison

    Conceptual models for transport at a redox boundary

  • R.R. De Vitre et al.

    Transformation of iron at redox boundaries

  • W.R. Fisher et al.

    The formation of hematite from amorphous iron(III)(hydr)oxide

    Clays and Clay Miner.

    (1975)
  • D. Perret et al.

    Characterizing authchthonous iron particles and colloids—the need for better particle analysis methods

  • Cited by (36)

    • Fe hydroxyphosphate precipitation and Fe(II) oxidation kinetics upon aeration of Fe(II) and phosphate-containing synthetic and natural solutions

      2016, Geochimica et Cosmochimica Acta
      Citation Excerpt :

      This suggests the formation of a single type of Fe hydroxyphosphate phase at initial aqueous P/Fe ((P/Fe)ini) ratios larger than ≈0.5. A limited number of studies indicate that P-rich precipitates with molar P/Fe ratio of 0.5–0.6 can form in the beginning of Fe(II) oxidation even when the (P/Fe)ini is less than 0.5 (Einsele, 1934; Tessenow, 1974; Deng, 1997; Gunnars et al., 2002; Voegelin et al., 2013). As a consequence, the P/Fe ratio in the solution progressively decreases when precipitates form which are relatively enriched in P. By using TEM and XAS, Voegelin et al. (2013) showed that, in solutions with (P/Fe)ini less than 0.5, early formation of amorphous Fe hydroxyphosphates is followed by the formation of short-range ordered ferrihydrite-type precipitates in silicate-containing solutions or poorly-crystalline lepidocrocite in silicate-free solutions when the solution becomes depleted in PO4.

    • Composition and structure of Fe(III)-precipitates formed by Fe(II) oxidation in water at near-neutral pH: Interdependent effects of phosphate, silicate and Ca

      2015, Geochimica et Cosmochimica Acta
      Citation Excerpt :

      Amorphous (Ca-)Fe(III)-phosphates did not only form at (P/Fe)init > (P/Fe)crit but were also the first phase precipitating at lower (P/Fe)init ratios (except the phosphate-free treatment). In previous studies, the initial precipitation of (Ca-)Fe(III)-phosphate during Fe(II) oxidation was inferred from changes in dissolved Fe(II) and phosphate concentrations (Einsele, 1938; Tessenow, 1974; Deng, 1997; Gunnars et al., 2002; Voegelin et al., 2013; van Genuchten et al., 2014a). In this study, we did not monitor the changes in solution and precipitate composition or in precipitate structure over time, but the changes in suspension color (Fig. 1) confirmed the initial formation of (Ca-)Fe(III)-phosphate precipitates.

    View all citing articles on Scopus

    [Fax: (305) 348 3772].

    View full text