Enhanced adsorption performance of alginate/MXene/CoFe2O4 for antibiotic and heavy metal under rotating magnetic field

Abstract Improving the adsorption performance with simple and strong applicability has always been a research hotspot in water treatment. This study introduces sodium alginate/MXene/CoFe2O4 (SA/MX/CFO) as functional composite materials by sodium alginate cross-linking and as adsorbents in the removal of contaminations with an external magnetic field (MF). SA/MX/CFO beads exhibited excellent mechanical properties, with fracture stress of 1.64 MPa at 73.4%, and an elastic modulus of 2.23 MPa. The isotherm fitting chose Cu2+ and CIP as the model pollutants, the isotherm fitting shows that the adsorption capacity of CIP is significantly improved by 24.2%.The magnetic effect of the adsorption capacity of Cu2+ is not obvious, which indicated the selectivity for adsorption; however, the adsorption rates of CIP and Cu2+ are greatly improved by 359.76% and 371% respectively. Promoting materials transfer rate, changing of hydrogen bond, and surface functional group reactivity is the key to determine the adsorption enhancement with a rotating magnetic field (RMF). The combination of the external magnetic field and the inherent magnetic properties of the adsorbent can adjust the adsorption process and the selectivity of pollutants. It also provides an innovative and practical method for MF to remediate contaminants in the magnetically enhanced adsorption system.