Synergistic Sustainable Strategies for Microplastic Pollution Eradication by Hedgehog − Shaped Polyoxometalate − Ionic Liquids Supported Magnetic Biochar

Microplastics (MPs) pollution in aquatic systems has been found to be an emerging environmental and health challenge. To overcome MPs pollution and for the sake of sustainable environment, we developed two innovative magnetic biochar adsorbents Q¹⁰ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc, and Q¹⁴ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc, for the optimized eradication of MPs from wastewater at industrial and laboratory scale. These composites composed of protein − size hedgehog − shaped polyoxometalate [Mo₃₆₈], hydrophobic polyoxometalate − based ionic liquids, magnetic nanoparticles, and sustainable rice husk char (Rhc) to achieve unmatched adsorption efficiency. Scanning electron microscopy and energy dispersive X-ray analysis displays the surface features and uniform distribution of elements throughout the material. While thermogravimetric analysis and nitrogen adsorption studies revealed a thermally stable and mesoporous nature of Q¹⁰ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc, and Q¹⁴ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc. Similarly, vibrating sample magnetometry measurements indicates the superparamagnetic behavior of Q¹⁰ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc, and Q¹⁴ [Mo₃₆₈] @ SiO₂ @ Fe₃O₄ @ Rhc. Batch adsorption experiments illustrated 100% removal efficiency for MPs across an extensive range of particle size (1–12.5 µm), from industrial wastewater as well as from laboratory water. Both adsorbents show a wide stability and efficiency over five removal cycles. These results suggest that both of the unique adsorbents are highly effective, sustainable, and versatile in complex aqueous environment, making them ideal candidates for large − scale environmental remediation.

Graphical Abstract