Phosphorus-goethite interactions: A review of mechanisms, environmental implications, and industrial relevance

Goethite (α-FeOOH) is among the most abundant and reactive iron oxyhydroxides in terrestrial systems, serving as a major sink and source for phosphorus (P) in both natural environments and industrial contexts. This review synthesizes current understanding of P association with goethite, exploring its occurrence, bonding mechanisms, and implications across soil science, mineralogy, and iron ore beneficiation. The strong affinity between P and goethite arises from its high surface area, structural flexibility to accommodate element substitutions, and the presence of surface hydroxyl groups that facilitate complexation reactions. In soils, these interactions influence P mobility, bioavailability, and long-term retention, while in iron ores, they represent a significant challenge due to the difficulty of removing P impurities during processing. The review traces the mineralogical pathways of P in goethite, distinguishing between adsorbed, incorporated, and mineral-hosted forms. It compiles global data on high-P goethite-rich iron ores and examines the variability in P distribution across different goethite morphologies. Advanced spectroscopic techniques such as X-ray Absorption Near Edge Structure (XANES), Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR), and Raman spectroscopy are evaluated for their capacity to resolve P speciation and bonding environments. Coupled with high-resolution microscopy and atom probe tomography, these tools offer unprecedented insight into the nanoscale mechanisms of P retention. By integrating mineralogical characterization with analytical advances, this review highlights the dual role of goethite in environmental nutrient cycling and industrial dephosphorization, while identifying critical gaps that must be addressed to better manage P in metallurgical systems.