Removal of polystyrene (PS) microplastics using a magnetic Fe₃O₄@MIL-101(Cr) composite

In this study, a Fe₃O₄@MIL-101(Cr) composite material was synthesized through a simple approach combining Fe₃O₄ and MIL-101(Cr), using waste PET as the raw material source. The obtained composite exhibited magnetic properties with a saturation magnetization of approximately 18 emu g⁻¹, compared with 50 emu g⁻¹ for pure Fe₃O₄. The synthesized materials were then employed as adsorbents for the removal of polystyrene (PS) microplastics from aqueous environments. The experimental results showed that under optimal conditions (pH = 8.15, room temperature, and an adsorbent dosage of Fe₃O₄@MIL-101(Cr) of 1.25 g L⁻¹), the removal efficiency of PS reached approximately 91.4 ± 3.74% after 150 min of interaction. Furthermore, the Fe₃O₄@MIL-101(Cr) composite could be easily recovered using an external magnetic field, demonstrating its potential as an environmentally friendly and recyclable adsorbent for the treatment of microplastic contamination in aquatic environments.