Ferrihydrite is a poorly crystalline iron oxyhydroxide mineral with the approximate formula Fe5HO8·4H2O. It's characterized by its extremely fine particle size, typically in the nanometer range, resulting in a high surface area. This high surface area contributes to its significant reactivity and adsorption properties.
Formation
Ferrihydrite forms in a variety of natural and anthropogenic environments. It frequently precipitates from aqueous solutions under oxidizing conditions, often through the oxidation of ferrous iron (Fe2+). Common formation sites include:
- Wetlands
- Soils
- Sediments
- Groundwater systems
- Industrial wastewater
Properties
Key properties of ferrihydrite include:
- Poor crystallinity: Lacks a well-defined crystal structure.
- High surface area: Provides significant adsorption capacity.
- Variable composition: Can incorporate other elements within its structure.
- Reactivity: Easily reacts with various substances.
- Nanoparticle size: Typically exists as nanoparticles, influencing its properties.
Applications
The unique properties of ferrihydrite lead to several applications, including:
- Water treatment: Used as an adsorbent to remove contaminants from water.
- Soil remediation: Assists in removing pollutants from contaminated soils.
- Catalysis: Can act as a catalyst in various chemical reactions.
- Nanomaterials: Used as a precursor in the synthesis of other iron-based nanomaterials.
Further Reading
For more in-depth information, you can refer to scientific literature on ferrihydrite. A good starting point could be searching scientific databases like Web of Science or PubMed using "ferrihydrite" as a keyword.
