Versatile magnetic adsorbent based on sodium p-styrenesulfonate modified sodium alginate composite for effective capture of antibiotic ciprofloxacin, methylene blue and copper ion

In this paper, a novel magnetic sorbent based on silica coated iron oxide (Fe3O4/SiO2, denoted as FS), poly(ethylene imine) (PEI), sodium p-styrenesulfonate (SPS) and sodium alginate (SA) polymer (Fe3O4/SiO2/SA-PEI-SPS, denoted as FSSEP) is successfully prepared by free radical polymerization. Antibiotic (ciprofloxacin, CPX), dye (methylene blue, MB) and heavy metal (copper ion, Cu2+) are used to test the adsorption capacity of the prepared adsorbent. Compared with other adsorbents, FSSEP exhibited good capture efficiency for the pollutants in this study, especially for organic pollutants (CPX and MB). The maximum sorption capacity of FSSEP reached 203.99 mg g−1 for CPX, 423.69 mg g−1 for MB, 41.81 mg g−1 for Cu2+. Hydrogen bonding, electrostatic interaction, π-π interaction and cationic exchange are involved in the sorption mechanism. This study suggests a strategy for the design and synthesis of eco-friendly modified sodium alginate adsorbents through free radical polymerization and explores their potential application in the field of removal of different types of toxic substances.