What is ferrihydrite used for?
What is ferrihydrite used for?
Ferrihydrite is a nanoparticulate ferric oxyhydroxide of unique importance across a range of fields1: it is widespread in soils and freshwater environments2,3; it forms a core structural component in the Fe-buffering ferritin protein, found in numerous organisms4,5; it is a major component of Fe-containing minerals on …
Where is ferrihydrite found?
On Earth, ferrihydrite is found in many surface and near-surface environments, including cold and hot springs, fresh and acid sulfate waters, lacustrine and marine sediments, and various types of soils [Chukhrov et al., 1972; Schwertmann and Fischer, 1973; Carlson and Schwertmann, 1981; Tipping et al., 1981; Eggleton.
What is 2line Ferrihydrite?
Two-line ferrihydrite (hereafter called ferrihydrite; bulk composition 5Fe2O3·9H2O) is a poorly crystalline Fe(III) oxyhydroxide that occurs as very small (2−4 nm) spherical particles in an aggregated form in natural settings (1-3).
How is Ferrihydrite formed?
In the natural environment ferrihydrite often forms by oxidation of Fe(II)aq at near neutral pH, (1) and under these conditions Fe13, if formed, would be expected to be highly transitory. In acidic conditions, such as in acid mine runoff, Fe13 may be more persistent.
Is Ferrihydrite a mineral?
Ferrihydrite (Fh) is a widespread hydrous ferric oxyhydroxide mineral at the Earth’s surface, and a likely constituent in extraterrestrial materials.
Is Ferrihydrite soluble?
Ferrihydrite, an amorphous Fe hydroxide (Fe(OH)3(s)), is depicted as controlling Fe(ii) solubility.
Is ferrihydrite a mineral?
What color is ferrihydrite?
Ferrihydrite is yellow-brown, red-brown or dark brown in color. The structure of ferrihydrite, however, has been difficult to determine because of the very fine particle size, the existence of poorly ordered versions of the mineral and the lack of synthetic well crystallized material.
Is ferrihydrite a crystalline?
Ferrihydrite is a metastable mineral. It is known to be a precursor of more crystalline minerals like hematite and goethite by aggregation-based crystal growth.
Is ferrihydrite soluble?
Is ferrihydrite magnetic?
These observations suggest that ferrihydrite is a potential magnetic remanence carrier under ambient environmental conditions. Measurements of mineral mixtures show that magnetic techniques can discriminate between ferrihydrite and goethite at low concentrations.
What color is Ferrihydrite?
How do you synthesize 2-line ferrihydrite?
Nano-structured 2-line ferrihydrite was synthesized by a pH-controlled precipitation technique at 90 °C. Chemical, X-ray diffraction ( XRD ), Fourier transform infrared ( FTIR) and Raman analyses confirmed the sample to be 2-line ferrihydrite.
What is the function of ferrihydrite?
It provides the inorganic base of ferritin in biological systems and is present as rust and in acid mine drainage. The large surface area and the high reactivity due to the complex surface make ferrihydrite a significant adsorbent of metals and organic species in natural waters.
How tetrahedrally coordinated are iron ions in ferrihydrite?
Zhao et al. (1994a,b) collected XAFS spectra on a series of ferrihydrite samples for a range of precipitation and drying conditions, and indicated that up to 25% of iron ions could be tetrahedrally coordinated.
What is the average domain size of ferrihydrite in XRD patterns?
The authors synthesized three average domain sizes (2, 3, and 6 nm) of ferrihydrite, the XRD patterns showed the presence of the same peaks, but the features were less pronounced in two-line (Fhyd2) and three-line (Fhyd3) ferrihydrite as compared to six-line (Fhyd6) ferrihydrite ( Fig. 8.2 ).
