One-pot synthesis of nano-MnFe2O4 decorated Al2O3 and its application in Cu2+ adsorption

Through coating the magnetic nano-MnFe2O4 onto the surface of Al2O3, a kind of magnetic composite of nano-MnFe2O4/Al2O3 adsorbent was synthesized successfully and used for the copper ions removal from simulated wastewater. The composite was characterised using a vibrating sample magnetometer, scanning electron microscopy, X-ray powder diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and a Brunauer–Emmett–Teller analysis. At the same time, the response surface method was used to optimize the reaction parameters. Moreover, the studies of adsorption isotherms and kinetics indicated that the Cu2+ adsorption process may be a multilayer chemical adsorption. It was worth noting that the increased concentration of F– favored the Cu2+ adsorption. Under the optimum conditions, when the initial concentration of Cu2+ was 20 mg/L and the adsorbent dosage was 0.20 g, the removal rate was 98.2%. In addition, after five cycles, the removal rate dropped only from 98.2% to 85.7%. This prepared magnetic adsorbent possessed excellent adsorption property and the characteristics of great reusability with quick solid-liquid separation from aqueous solution under external magnetic field added, which indicated its potential practical application for the Cu2+ removal from wastewater.