Purification of metronidazole and penicillin-G contaminated water by MOF-5 imprinted cobalt ferrite

Abstract

Water contamination by antibiotics such as metronidazole (MTZ) and penicillin-G (PCG) is a serious concern. Therefore, this study evaluates the potential of cobalt ferrite (CoFe2O4) and cobalt ferrite imprinted terephthalic acid-zinc metal–organic framework (CoFe2O4@MOF-5) as adsorbents for the removal of MTZ and PCG from contaminated water sources. The scanning electron micrograph revealed the surfaces of CoFe2O4 and CoFe2O4@MOF-5 to be heterogeneous with irregularly shaped particles, while the Brunauer-Emmett-Teller (BET) surface area was found to be 16.63 and 12.41 m2/g for CoFe2O4 and CoFe2O4@MOF-5, respectively. The X-ray diffraction (XRD) revealed a crystallite size of 28.31 nm for CoFe2O4 and 29.01 nm for CoFe2O4@MOF-5. CoFe2O4@MOF-5 exhibited higher sorption capacity towards MTZ (94.47 mg g−1) and PCG (90.28 mg g−1) than values displayed by CoFe2O4 towards MTZ (50.41 mg g−1) and PCG (55.76 mg g−1). The sorption process may be described by the Langmuir and Freundlich isotherms with a quantum chemical simulation analysis that revealed the process mechanism to be via electronic interaction. The regeneration capacity of CoFe2O4@MOF-5 was higher than that of CoFe2O4, with a regeneration capacity of 91.71 % for MTZ and 89.31 % for PCG at the 10th regeneration cycle. Furthermore, CoFe2O4@MOF-5 compared favourably with previously reported adsorbents. The study's findings revealed CoFe2O4@MOF-5 as a promising material for the purification of water contaminated with MTZ and PCG.

Keywords

• Adsorption
• Antibiotics
• Metal-organic framework