Adsorption and transformation of tetracyclines on alpha alumina particles with surface modification by anionic surfactant.

The adsorption and transformation of tetracyclines (TCs) antibiotics, including oxytetracycline (OTC), chlortetracycline (CTC), and tetracycline (TC), on the sodium dodecyl sulfate (SDS) surfactant-modified α-Al ₂ O ₃ particles were comprehensively investigated in this study. The TCs adsorption was significantly enhanced by using the modified adsorbents compared with the use of the unmodified adsorbents. The experimental conditions were systematically optimized and found to be pH 4, NaCl 1 mM, the contact time of 180 min, and the adsorbent dosage of 25 mg. mL ^-1 . The high maximum adsorption capacities were approximately 320, 85, and 91 mg. g ^-1 for TC, OTC, and CTC, respectively. Meanwhile, the great removal efficiencies of the three antibiotics TC, OTC, and CTC were correspondingly 91.85, 88.4, and 98.3%. The TCs adsorption isotherm and kinetics on the SDS-modified α-Al ₂ O ₃ particles mainly governed by the electrostatic and hydrophobic interactions were clarified by a suitable two-step model, the Fourier transform infrared spectroscopy (FT-IR) and zeta potential measurements. Meanwhile, the TCs structural transformation determined by the liquid chromatography with tandem mass spectrometry (LC-MS/MS) measurement was promoted through the adsorption on the α-Al ₂ O ₃ surface. The TCs transformation rates strongly affected by the TCs adsorption were in the order of CTC > TC > OTC. The found results are promised that the SDS-modified α-Al ₂ O ₃ particles might behave as high-performance adsorbents to remove the TCs from aqueous solutions.
Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Tien Duc Pham reports equipment, drugs, or supplies was provided by Vietnam National University Hanoi. Tien Duc Pham reports a relationship with Vietnam National University Hanoi that includes: employment. None has patent None pending to None.
(Copyright © 2022 Elsevier Inc. All rights reserved.)