Magnetic Iron-Based Oxide Materials for Selective Removal and Recovery of Phosphorus

Phosphorus (P) is a nonrenewable resource with finite reserves, while excess phosphorus inevitably enters water environment and causes eutrophication. Therefore, a novel technology that can remove and recover phosphate from wastewater and natural water is desirable. Compared with other technologies such as chemical precipitation and biological processes, adsorption is a favorable option for its simplicity in design, ease of operation, and minimal waste production. Although various adsorbents have been developed, some drawbacks limit their application in the field. Thus, the magnetic iron-based oxide materials in the form of core-shell structure and composites (i.e. ZrO₂@Fe₃O₄, La(OH)₃/Fe₃O₄ and Fe⁰/Fe₃O₄) have been developed for phosphorus removal and recovery with strong selectivity, high adsorption capacity, favorable reusability, and easy material separation by magnetic field. Various characterization methods were used to examine their properties, and batch experiments were conducted to investigate phosphorus removal and recovery performance. The results show a high potential of magnetic iron-based oxide materials for being used in possible phosphorus removal and recovery applications in the future.