Graphene could help us turn seawater into drinking water


Graphene continues to amaze and surprise us with its amazing capabilities with the latest being the ability to turn seawater into drinking water.

University of Manchester scientists have published a new study in the journal Nature Nanotechnology wherein they have demonstrated the real-world potential of providing clean drinking water for millions of people through the use of graphene-oxide membranes that are capable of sieving common salts.

Addressing a previous challenge of ensuring that graphene-oxide membranes do not swell and let smaller salts flow across, scientists at the university have developed membranes that do not swell when exposed to water. Scientists have developed a technology using which the pore size in the membrane can be precisely controlled to turn sea or salty water into drinkable water.

When the common salts are dissolved in water, they always form a ‘shell’ of water molecules around the salts molecules. This allows the tiny capillaries of the graphene-oxide membranes to block the salt from flowing along with the water. Water molecules are able to pass through the membrane barrier and flow anomalously fast which is ideal for application of these membranes for desalination.

Researchers at the university have developed membranes that are not only useful for desalination, but the atomic scale tunability of the pore size also opens new opportunity to fabricate membranes with on-demand filtration capable of filtering out ions according to their sizes.

By 2025 the UN expects that 14 per cent of the world’s population will encounter water scarcity. This technology has the potential to revolutionise water filtration across the world, in particular in countries which cannot afford large scale desalination plants.

It is hoped that graphene-oxide membrane systems can be built on smaller scales making this technology accessible to countries which do not have the financial infrastructure to fund large plants without compromising the yield of fresh water produced.