High Capacity and Efficient Adsorption of Lutetium(III) by the Metal-Organic Framework HKUST-1 in Simulated Medical Wastewater.

Lutetium (Lu(III)), a heavy rare earth element, plays a critical role in advanced industrial processes and nuclear medicine applications. Given its high economic value and potential environmental risks, the recovery of Lu(III) from medical wastewater is both necessary and urgent. However, previous studies on the adsorption behavior of Lu(III) have been limited by low adsorption capacity, competition from coexisting metal ions, and the influence of environmental temperature. In this work, a copper (Cu)-based, conventional metal-organic framework (MOF) material named HKUST-1 was employed for the recovery of Lu(III). The effects of pH and shaking speed, adsorption isotherms, and adsorption kinetics were systematically investigated. The maximum adsorption capacity was 512.82 mg·g-1, calculated with the Langmuir isotherm model. Comprehensive characterization suggested that the adsorption mechanism involves ion exchange between Lu(III) and Cu(II), as well as the formation of Lu─O covalent bonds. Furthermore, adsorption experiments using simulated medical wastewater were conducted to evaluate the practical applicability. This work highlights a promising strategy for Lu(III) recovery from aqueous waste streams, demonstrating the high efficiency and application potential of HKUST-1 in environmental remediation.