A facile cross-linking copolymerization strategy to synthesize anionic magnetic hydrogels for efficient removal of tylosin tartrate

The novel magnetic hydrogel adsorbents were prepared using a facile cross-linking copolymerization method and applied for the adsorption of tylosin tartrate. A series of characterization tests were conducted to investigate the functional group structure, thermal stability, surface morphology, and magnetic properties of the adsorbents. Furthermore, the influence of dosage, initial concentration of tylosin tartrate, adsorption time and pH value on the adsorption performance of the adsorbent were studied. Batch adsorption results demonstrated that Mag@GAS exhibited the highest adsorption capacity of 188.64 mg/g. Furthermore, the sulfonic acid groups on the surface of Mag@GAS showed minimal pH dependency, allowing for high adsorption capacity over a wide pH range. The zeta potential experiments investigated the adsorption mechanism of Mag@GAS towards TST under different pH values. The pseudo-second-order rate model described adsorption kinetics data well, indicating that adsorption process was mainly controlled by intra-particle diffusion and film diffusion. The adsorption isotherm data fitting using the Freundlich isotherm model showed good agreement. The results showed that the adsorption process of TST by Mag@GAS was a multilayered heterogeneous surface adsorption. The thermodynamic parameters indicated the spontaneous and endothermic adsorption. Additionally, regeneration experiments demonstrated that Mag@GAS was easily separable and effectively regenerated. Therefore, Mag@GAS shows great potential as an adsorbent.