A simple way of cleaning water of various contaminants (from lead and mercury to dye and antibiotics) was shown in a proof-of-concept study at Monash University (that also involved MIT and Bristol University), using graphene oxide and magnets.
The method relies on strong magnets that draw charged particles out of water as it flows through a pipe. The particles are attached to tiny sheets of graphene oxide, which attract a huge range of toxins. Graphene oxide's ability to “sponge” metal ions made the new system a promising way of treating mine tailing dams.
This method also uses fully recyclable components, as the graphene oxide can be separated from the magnetic materials and can be reused many times over.