Highly Efficient Adsorption of Tetracycline Using Chitosan-Based Magnetic Adsorbent

Herein, tetracycline adsorption employing magnetic chitosan (CS center dot Fe3O4) as the adsorbent is reported. The magnetic adsorbent was synthesized by the co-precipitation method and characterized through FTIR, XRD, SEM, and VSM analyses. The experimental data showed that the highest maximum adsorption capacity was reached at pH 7.0 (211.21 mg g(-1)). The efficiency of the magnetic adsorbent in tetracycline removal was dependent on the pH, initial concentration of adsorbate, and the adsorbent dosage. Additionally, the ionic strength showed a significant effect on the process. The equilibrium and kinetics studies demonstrate that Sips and Elovich models showed the best adjustment for experimental data, suggesting that the adsorption occurs in a heterogeneous surface and predominantly by chemical mechanisms. The experimental results suggest that tetracycline adsorption is mainly governed by the hydrogen bonds and cation-pi interactions due to its pH dependence as well as the enhancement in the removal efficiency with the magnetite incorporation on the chitosan surface, respectively. Thermodynamic parameters indicate a spontaneous and exothermic process. Finally, magnetic chitosan proves to be efficient in TC removal even after several adsorption/desorption cycles.

Automated summary

This study reports on the adsorption of tetracycline using magnetic chitosan as the adsorbent. The highest adsorption capacity was achieved at pH 7.0, and the efficiency of the adsorbent depended on pH, initial concentration, and dosage. Ionic strength significantly affected the process. The Sips and Elovich models provided the best fit for the experimental data, indicating heterogeneous surface adsorption predominantly through chemical mechanisms. The adsorption of tetracycline was governed by hydrogen bonds and cation-pi interactions, and the incorporation of magnetite on the chitosan surface enhanced its removal efficiency. Thermodynamic parameters suggested a spontaneous and exothermic process. Magnetic chitosan proved to be effective in tetracycline removal even after multiple adsorption/desorption cycles.