Dual-functional UiO-66-(COOH)2 mixed-matrix membrane for integrated radionuclide sequestration and catalytic degradation of pharmaceutical contaminant from water

초록

The co-existence of hazardous radionuclides and pharmaceutical contaminants in aquatic environments underscores the urgent need for advanced materials capable of comprehensive water remediation. In this study, a novel dual-functional mixed-matrix membrane (UCM-2) was successfully fabricated by embedding a carboxylfunctionalized metal-organic framework, UiO-66-(COOH)(2), into a PVDF/PVP polymer matrix. UCM-2 exhibited outstanding dual functionality, serving as both an adsorbent and a heterogeneous catalyst. As an adsorbent, it achieved maximum uptake capacities of 5.81 mg/g for Co-60 and 4.81 mg/g for 85,90Sr, primarily driven by electrostatic interactions and inner-sphere complexation. In parallel, the pristine UCM-2 effectively activated peroxydisulfate, enabling the rapid degradation of sulfamethoxazole, with 91.6 % removal achieved within 30 min. Scavenger experiments and ESR analysis revealed that the catalytic process was governed by a complex suite of reactive oxygen species, with superoxide (O-2(center dot-)), sulfate radicals (SO4 center dot-), and singlet oxygen (O-1(2)) identified as the dominant contributors. Crucially, UCM-2 maintained robust performance for both functions even in complex aqueous matrices, including tap water, surface water, and wastewater effluent. Unlike conventional single-function adsorbents or catalysts, UCM-2 integrates both adsorption and catalytic degradation with a single, stable membrane, thereby minimizing operational complexity, while enhancing stability and reusability. This dual-functional platform can be readily extended to other radionuclide-pharmaceutical co-contaminant systems, providing a promising strategy for next-generation integrated water purification technologies.

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