Researchers at the University of Ulm, the Helmholtz Institute in Ulm, and CISC-Universidad de Zaragoza have developed a new water purification method using magnetic nanoparticles coated with an ionic liquid that is capable of removing organic, inorganic, microplastic and microbial contaminants simultaneously.
The nanoparticles consist of a core of magnetic iron oxide and a shell of porous silicon dioxide. The surface is then coated with a layer of an ionic liquid, which is a salt that is in its molten state at room temperature, making it a liquid without the need of a solvent. The ionic liquid is based on polyoxometallates (POMs), which are metal atoms bound into a three-dimensional network by oxygen atoms.
The nanoparticles removed lead, nickel, copper, chromium, and cobalt ions, as well as a dye called Patent Blue V as a model for organic impurities. The growth of various bacteria was also effectively stopped along with the removal of polystyrene spheres (a model for microplastics 1 to 10 μm in diameter).
Their results are published in the journal Angewandte Chemie.