Possible adsorption mechanisms of the removal of tetracycline from water by La-doped Zn-Fe-layered double hydroxide

Abstract

The present study evaluated the adsorbent efficiency of Zn/Fe/La-layered double hydroxides (LDH) in the removal of tetracycline (TC) from aqueous solutions. It investigated the physical and chemical properties of the prepared materials before and after adsorption using X-ray diffraction, Fourier transform infrared analysis, energy dispersive X-Ray, zeta potential, particle size, and field emission scanning electron microscopy. The effects of the pH of the solution and adsorbent dose on the TC adsorption process were evaluated. The adsorption isotherm and the kinetic studies of the TC adsorption process were applied at a pH of 5.0 and at a temperature of 25 °C using several isotherm and kinetic models. The maximum TC removal by Zn/Fe/ La LDH was 80%. The Monte Carlo and molecular dynamics simulations were used to explain the mechanism of the adsorption process on the Zn/Fe/La LDH (001, 010, and 100) surfaces. Furthermore, a good antibacterial activity was associated with the use of Zn/Fe/La LDH against fungi, gram-positive, and gram-negative bacteria strains.