Graphene Sieve Turns Saltwater into Drinking Water.
This is good news for Coleridge’s ancient mariner and for everyone in need of fresh water.
According to the United Nations, 85 percent of the global population lives in the driest half of the planet, 783 million people do not have access to clean water, and almost 2.5 billion do not have access to adequate sanitation.
Desalination, or removing salt from seawater to make it drinkable, is not a new idea.
Speaking of other membranes, yes, there are already several large desalination plants around the world trying to use polymer-based membranes to filter the salt out of seawater, but the process is too inefficient and expensive for widespread use.
Thus, finding a way to turn seawater into drinking water more quickly and with minimal expense has been a key goal in the latest research.Rahul Nair from the University of Manchester is optimistic.
We also demonstrate that there are realistic possibilities to scale up the described approach and mass-produce graphene-based membranes with required sieve sizes.”Graphene oxide membranes have long been considered a promising candidate for desalination, but successfully removing salt requires the holes in the graphene oxide membrane the water passes through to be incredibly tiny.
Even though this new desalination technology is restricted to the laboratory for now, in the not-too-distant future it may be used to change an extremely abundant resource—seawater—into a very rare one—drinkable fresh water.
Tunable sieving of ions using graphene oxide membranes.
doi:10.1038/nnano.2017.21 Featured image: Graphene oxide desalination sieve.