Removal of metronidazole from aqueous medium by adsorption on Co-Zr LDH

Metronidazole is an antimicrobial, antibacterial and antiprotozoal drug that is applied to treat many infections. However, it has been considered as a pollutant in water bodies. In this study, Co-Zr layered double hydrodxide (LDH) was synthesized using cobalt and zirconium metal salts by mechanochemical method. Layered double hydroxides are generally described as [M²⁺_1-xM³⁺_x(OH)₂]^x+(A^n-)_x/n·mH₂O, where M²⁺ and M³⁺ are divalent and trivalent metal cations, respectively. Here, we used divalent and tetravalent metal cations and A is an n-valent interlayer guest anion. The LDH was characterized by XRD, FE-SEM and IR methods, and then was used to adsorb metronidazole in aqueous solution. We have optimized the pH to obtain the maximum adsorption capacity which was determined by UV-VIS spectroscopy. The results showed that this adsorbent had better performance than previous studies.