Membranes for the degradation of water pollutants

Schematic of a flow reactor containing the developed hybrid membrane capable of
Schematic of a flow reactor containing the developed hybrid membrane capable of degrading tyrosol present in water by a Fenton reaction. Caption / UAM

A team of researchers from the Autonomous University of Madrid (UAM) has developed hybrid membranes based on a functional porous nanomaterial and a polymer, capable of effectively degrading emerging contaminants present in water. The work, published in the journal Nanoscale, promises to significantly improve water quality and contribute to the development of sustainable treatment methods.

Researchers from the Autonomous University of Madrid (UAM), belonging to the Department of Inorganic Chemistry of the Faculty of Sciences, have developed a new technology for the degradation of contaminants present in water by using hybrid membranes that integrate stabilized Cu-MOF-808 nanoparticles in a polymeric matrix.

The work, described in the journal Nanoscale, could represent a significant step in the fight against emerging contaminants, such as pharmaceuticals, microplastics and personal care products, which currently have no effective disposal solution.

"Metal-Organic Frameworks (MOFs), due to their porous structure that allows the specific design of their pores, emerge as highly promising materials for applications such as gas capture and separation, heterogeneous catalysis and controlled drug release," the authors explain.

"Specifically," they add, "for our study we selected MOF-808 for its high stability in water. And it was metallized with Cu(II) ions, allowing the degradation of contaminants by the Fenton reaction, an advanced oxidation method."

Hybrid membranes with nanoparticles

To overcome the processing limitation of MOFs, typically obtained in powder form, the researchers incorporated Cu-MOF-808 into a polymeric matrix, thus creating a hybrid membrane. "This design facilitates their use in practical applications while maintaining the integrity of the copper catalytic sites essential for catalysis," the authors explain.

The performance of these membranes was evaluated in continuous flow reactors, demonstrating efficient degradation of the pollutant tyrosol in water.

The analyses were performed by UV-Visible spectroscopy and inductively coupled plasma mass spectrometry (ICP-MS), among other advanced characterization techniques that corroborated that the structure of the nanostructured material was not affected.

The results indicated that the membrane significantly reduced copper release, by more than 50% compared to the powdered form of the material.

"This study not only highlights advances in heterogeneous catalysis for water purification, but also opens avenues for the design of new membranes with improved catalytic properties, thus enhancing water quality and contributing to environmental protection and the development of globally sustainable technologies," the authors conclude.

Bibliographic reference:

del Castillo-Velilla, I.; Romero-Muņiz, I.; Marini, C.; Montoro, C.; Platero-Prats, A.E. (2024). "Copper Single-Site Engineering in MOF-808 Membranes for Improved Water Treatment". Nanoscale, 16, 6627-6635. doi.org/10.1039/D3NR05821B.

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