Application of Co-Zr Layered Double Hydroxide in Removing Metronidazaole as an Environmental Pollutant

Metronidazole is an effective antibiotic and is used to prevent and treat infections caused by anaerobic and antiphrastic bacteria. The bacteria usually grow inside and outside of the body where there is no oxygen (such as the gums, pelvis, and abdomen, intestines and etc.). Antibiotics aren't completely metabolized in human body and move through the environment as an active compound. The water purification process for those contaminated by metronidazole antibiotics is difficult using conventional methods and sometimes impossible, due to low degradability and high water solubility. In general, there are several methods to remove antibiotics, such as ultraviolation, photocatalysis, carbon nanotubes, nanofiltration and so on. Recently, layered double hydroxides have been shown a significant reactivity for removing metronidazole from aqueous solutions. Layered double hydroxides have the general formula as [MII(۱-x)MIIIx(OH)۲]x+·Ax/mm−·nH۲O, where MII is a divalent metal cation, MIII is a trivalent metal cation and A is an interlayer guest anion. Based on this research, Co-Zr LDH was synthesized using divalent cobalt and tetravalent zirconium salts by a green solventless mechanochemical method. By changing the pH as an effective parameter on adsorption, the environmental charge and the equilibrium ionization of the solutes can be affected. It was concluded that layered double hydroxide can successfully adsorb metronidazole at pH ۶. Thus, the process of drug uptake by Co-Zr LDH is an effective method to remove the antibiotic from aqueous solutions as regards to the low cost, green synthesis method and great efficiency. The results showed that the adsorbent had better performance than previous studies.

کلیدواژه ها:

LDH ، Adsorption ، Metronidazole ، Pollution