Synthesis of ferromagnetic 3DOM MgO/MgFe2O4 with superb adsorption capacity and convenient recovery properties for efficient capture of La(Ⅲ) and Ce(Ⅲ) from wastewater

Abstract

The mining of ion-adsorption rare earth minerals or ores generated a large amount of wastewater containing rare earth elements at low-concentration, resulting in continuous environmental pollution. For this problem, our study prepared an efficient, recyclable MgO/MgFe2O4 magnetic adsorbent, synthesized by a template method and characterized using XRD, SEM-EDS, BET, and VSM. The isothermal adsorption experiments and adsorption kinetic experiments were carried out to evaluate the ability of MgO/MgFe2O4 to remove La(Ⅲ) and Ce(Ⅲ), and the effects of the initial pH of the solution and the dosage were also investigated. FT-IR and XPS analyzed the ion-exchange mechanism between La(III) and Ce(III) ions and the hydroxyl functional groups present in the adsorbent, culminating in the formation of La/Ce-OH complexes. MgO/MgFe2O4 demonstrated a theoretical adsorption capacity of 2002 mg/g and 5317 mg/g for La(III) and Ce(III), respectively, achieving removal rates of 97.2% and 98.7% in dilute solutions, marking it as a potent solution for rare earth element remediation in wastewater. This advancement holds substantial implications for environmental management within rare earth mining locales.