Adsorptive removal of nitrate from aqueous solution using a MnFe2O4@zeolite-activated carbon magnetic nanocomposite: isotherm and kinetics studies

Abstract

Nitrate elimination from groundwater and surface water has received growing attention in recent years, as its gradual accumulation severely endangers freshwater reserves around the world. To this end, a new and effective zeolite-activated carbon supported MnFe₂O₄ magnetic nanocomposite was synthesized and used as a nanoadsorbent for nitrate removal from water for the first time in this research. Subsequently, several analytical techniques, including field emission scanning electron microscopy (FE-SEM), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD), were applied to identify the MnFe₂O₄@zeolite-activated carbon magnetic nanocomposite. To attain the maximum removal efficiency of nitrate, several key parameters were optimized, such as dosage of adsorbent, contact time, initial concentration, and solution pH. Kinetic studies and adsorption equilibrium analysis indicated that the pseudo-second-order model is well matched with the experimental kinetics data, while the Freundlich isotherm model provides a better representation of the nitrate adsorption process. The outcomes displayed that the MnFe₂O₄@zeolite-activated carbon magnetic nanocomposite is a promising nanoadsorbent for the elimination of nitrate from water.