A Review of Research Progress on Detection Methods and Environmental Behaviors of Phytic Acid and Its Degradation Products in Groundwater Systems

Phytic acid (IP6) accounts for 50%–80% of organic phosphorus. It is input into groundwater systems via plant and animal residues, agricultural activities (e.g., decomposition of phosphate fertilizers and livestock manure), and phytic acid-containing wastes from industrial production. Subsequently, it migrates and transforms in groundwater and aqueous media. Through water-aqueous medium-microorganism reactions, phytic acid affects the occurrence form and bioavailability of phosphorus, posing risks of agricultural non-point source pollution and water eutrophication. This review elaborates on the physicochemical properties, sources, and occurrence forms of phytic acid, compares various detection technologies for phytic acid and its degradation products, and reveals the mechanisms underlying the main environmental behaviors of phytic acid. Existing studies have shown the following: (1) Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be used more effectively separate and quantify phytic acid and its degradation products, with high sensitivity, accuracy and precision. (2) The main environmental behaviors of phytic acid in groundwater systems include hydrolysis, biodegradation, and adsorption–desorption, which are mainly regulated by factors such as temperature, pH, hydrochemical components, and mineral composition of the medium. (3) The hydrolysis rate is most significantly affected by temperature, increasing with rising temperature. Biodegradation mainly relies on the secretion of phytase to attack specific phosphate ester bonds, thereby gradually removing phosphate groups and ultimately producing inositol and phosphate ions. Adsorption–desorption has the fastest reaction rate, and phytic acid is adsorbed on mineral surfaces mainly through electrostatic interaction, hydrogen bonding, and coordination complexation. Among these, iron-aluminum (hydro)oxides exhibit the strongest adsorption capacity for phytic acid. Coexisting oxyanions in groundwater systems (e.g., \mathrmAsO_3^3- , \mathrmAsO_4^3- , and inorganic phosphate \mathrmPO_4^3- ) can also compete with phytic acid for adsorption sites. Phytic acid has a stronger affinity for mineral surfaces, enabling it to desorb adsorbed As and inorganic phosphorus, thereby increasing their bioavailability and raising their eco-environmental risks. It is suggested that future research should focus on the following directions: (1) the biological and abiotic degradation pathways of mineral-adsorbed phytic acid, as well as the environmental risks of its degradation products; (2) the impact of phytic acid on the environmental behaviors of various coexisting metal oxyanions; (3) the construction of a multi-factor coupling model for the migration and transformation of phytic acid and its degradation products in aqueous media, so as to provide a theoretical basis for analyzing phosphorus cycling mechanisms and preventing pollution. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202503280063.