Hierarchical flower-like magnesium oxide microspheres for efficient removal of copper

Magnesium oxide (MgO) as an adsorbent has gained attention due to its abundance in nature for the removal of copper (Cu). The flower-like hierarchical porous MgO was synthesized through the ethylene glycol (EG) assisted precipitation method. The role of different concentrations of EG on the MgO formation and Cu removal was investigated. The maximum 500 mg/g of Cu was removed from the solution, which is greater than the reported adsorbents. Furthermore, the adsorption kinetic, isotherm, and possible adsorption mechanism was also explored in this study. It was found that the Cu removal followed a pseudo-second-order kinetic and Langmuir isotherm model. Surface adsorption, cation exchange, and complex formation are the possible mechanisms of Cu removal. Thus, the study provides a new insight into the removal of metal cation from water using low-cost materials.