Study on selective adsorption and separation of dysprosium by a multi-template oriented imprinted composite membrane

Abstract

Dysprosium (Dy) ion has received widespread attention in industrial applications due to its unique physical and chemical properties. The potential economic value of adsorbing and separating rare earth Dy ions from waste permanent magnets is high. We use graphene oxide as the material to pre-pare the membrane for selective adsorption of Dy. Graphene oxide has high stability, its structure is two-dimensional plane, and it has high acid and alkali resistance. At suitable pH conditions, the prepared membranes can have high selective adsorption properties to Dy ions by ionic imprint-ing. A series of studies on the effects of various pH on the adsorption effect, isotherm, kinetics, and competitive adsorption and so on were carried out. The model of selective adsorption of Dy ions was proposed to obtain membrane materials with good selectivity and good separation. We found that at pH = 5.0, the adsorption performance of the membrane for Dy ions was the best, and the adsorption reached equilibrium after 2 h of adsorption. The maximum adsorption amount reached 26.27 mg g–1 . The membrane has high acid resistance and high adsorption selectivity to Dy ions.