Enhanced removal of gatifloxacin by Fe3O4@bacteria: Performance and mechanism

A novel magnetic biobased material, synthesized from nano Fe 3 O 4 and degrading-bacteria, was developed for the effective removal of gatifloxacin (GAT). Investigations into various parameters influencing the adsorption process revealed that the optimal adsorption capacity of 56.63 mg/g for GAT was achieved under mildly acidic conditions. Furthermore, the adsorption capacity of GAT increased with temperature, specifically within the range of 20 °C to 30 °C, while a decrease was noted at lower concentrations of NaCl. The adsorption kinetics of GAT onto Fe 3 O 4 @bacteria were best described by the pseudo-second-order (PSO) kinetic model and the Langmuir isotherm model. Thermodynamic evaluations confirmed that the adsorption process was both endothermic and spontaneous. The primary mechanisms driving the adsorption of GAT included pore filling, π-π conjugation, hydrogen bonding, and electrostatic interactions. Therefore, Fe 3 O 4 @bacteria was established as an effective and environmentally sustainable adsorbent for the removal of GAT.