Computational and experimental studies on the efficient removal of diclofenac from water using ZnFe-layered double hydroxide as an environmentally benign absorbent

In this study, Zn–Fe LDH was prepared by co-precipitation method and characterized using different analytical instruments including X-ray diffractometer (XRD), zeta potential, Fourier-transform infrared spectrometry (FTIR) spectroscopy, X-ray diffractometer (XPS), Field emission scanning electron microscope (FESEM), and High resolution transmission electron microscope (HRTEM). Also, the efficiency of Zn–Fe LDH as adsorbent for the removal of diclofenac sodium (DCF) from aqueous solution was investigated under different experimental conditions, such as pH, dose of adsorbent, pollutant concentration, and contact time. The Zn–Fe LDH has successfully removed a high percentage of diclofenac from water within 30 min, and its adsorption capacity at equilibrium was 74.50 mg/g. Several isothermal and kinetic models of the adsorption process were investigated. It was found that diclofenac adsorption was best fitted with three and four-parameter isotherms and the pseudo-second order kinetic model. The surface adsorption mechanism was explored computationally by means of Monte Carlo and molecular dynamic simulations in gas and water phases. The simulation results have shown that diclofenac strongly interacts with Zn–Fe LDH through a variety of hydrogen bonds, as well as metal complexation. The in-vivo toxicity study in mice revealed the safety of Zn–Fe LDH on different body organs through estimation the median lethal dose that kill 50% of the animal numbers.
Source: Journal of the Taiwan Institute of Chemical Engineers - Category: Chemistry Source Type: research