A new way of filtrating salt water could provide millions with clean drinking water.

Graphene-oxide membranes developed by the National Graphene Institute can separate the salt from seawater, according to a study published in the journal Nature Nanotechnology on April 3.

The technology could be used for the desalination of seawater, currently a very expensive process.

Graphene is the world's thinnest material but is also very strong.

The membranes have been shown to be able to filter out "small nanoparticles, organic molecules, and even large salts", said the University of Manchester, where the institute is based.

Sieving out common salt required even smaller "holes", which scientists at the university have engineered.

The tiny capillaries of the graphene-oxide membranes not only filters the salt, water molecules flow anomalously fast through the membrane, which is ideal for desalination, it added.

The researchers have managed to produce "scalable membranes with uniform pore size down to atomic scale", said Professor Rahul Nair.

It will "open new possibilities for improving the efficiency of desalination technology," he said.