Phenolic hydroxyl derived copper alginate microspheres as superior adsorbent for effective adsorption of tetracycline

Significant concerns had been given raise to the pollution of tetracycline in aquatic environment in recent years. In this study, a novel phenolic hydroxyl (bayberry tannin) functionalized copper alginate microspheres adsorbent for the adsorption of tetracycline from contaminated water environment had been synthesized by a facile gelation and solidification process. The structure and chemical properties were characterized by the various analytical methods. The as-prepared adsorbent displayed the excellent adsorption performance with the maximum adsorption capacity of 153.89 mg·g^-1, and the equilibrium data were well fitted the Langmuir isotherm model and pseudo-second-order kinetic model. In addition, the thermodynamic values (ΔH⁰ > 0, ΔS⁰ > 0, ΔG⁰ < 0) demonstrated that the tetracycline adsorption process was feasible, endothermic and spontaneous in nature. The possible preparation and adsorption mechanisms of as-prepared adsorbent were the result of hydrogen bond, cation bonding bridge, n-π EDA interaction, hydrophobic interaction and π-π EDA interaction. Compared with other adsorbents, the as-prepared adsorbent could be considered a high performance and promising candidate for the effective removal of tetracycline from aquatic environment.