Magnetic microalgae loaded with ZIF-8 composite materials for efficient capture of iodine from radioactive wastewater: synthesis, characterization and recovery

Radioactive iodine from nuclear accidents like Fukushima necessitates efficient wastewater treatment technologies. Current adsorbents are hampered by challenging recovery and limited reusability. Herein, we synthesize a magnetic composite, GS@Fe3O4@ZIF-8, by anchoring ZIF-8 to magnetized Galdieria sulphuraria(GS), allowing for sub-one-minute magnetic separation. This adsorbent achieves a high iodine adsorption capacity of 1712.08 mg/g at pH 5, outperforming most MOF-based benchmarks. Characterization (XRD, SEM, FT-IR, XPS, EDS) verified its structure. Adsorption studies determined the optimal conditions (pH 5) and demonstrated robust performance across varied concentrations, temperatures, and times. The material also exhibits superior selectivity and stability, retaining 83% efficiency over three cycles. Our findings highlight GS@Fe3O4@ZIF-8 as a sustainable and recyclable material for radioactive iodine capture.