Magnetic separation for sustainable phosphorus recovery: Advances, challenges, and future perspectives

Phosphorus recovery from wastewater has gained increasing attention due to environmental concerns and resource scarcity. This review investigates magnetic separation as an innovative method for phosphorus removal and recovery, highlighting its advantages over conventional techniques. High-gradient magnetic separation (HGMS) systems, including rotor-stator, centrifugal, and superconducting designs, demonstrate high recovery efficiencies. The integration of magnetic adsorbent particles, particularly those coated with layered double hydroxides (LDHs), chitosan, and silica, enhances selectivity and reusability. Various studies report adsorption capacities exceeding 50 mg∙g −1 for phosphate, with effective desorption strategies ensuring process circularity. The potential for combining HGMS with open-gradient magnetic separation (OGMS) and other hybrid systems is discussed, emphasizing scalability challenges and economic feasibility. While magnetic separation shows promise for phosphorus recovery, further research is needed to optimize particle design, desorption efficiency, and large-scale implementation. • Magnetic separation enables sustainable phosphorus recovery from wastewater. • High-gradient systems could possibly achieve >90% phosphate removal with magnetic nanoparticles. • Layered double hydroxide coatings improve adsorption and reusability of particles. • Combining HGMS and OGMS enhances scalability for full-scale water treatment. • Magnetic recovery reduces chemical use and supports circular water management.