- New research shows graphene can filter common salts from water to make it safe to drink
- Findings could eventually lead to affordable desalination technology
Scientists from the University of Manchester, where miracle material Graphene was first isolated and characterised in 2004, have created a promising graphene oxide sieve capable of salt filtration.
For some time, Grapheneoxide membranes have been considered to be promising candidates for new filtration technologies. Recently, an important further development has taken place. Membranes capable of sieving common salts have been created.
Graphene-oxide membranes developed at the National Graphene Institute in Manchester have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Up until now, they have been unsuccessful in sieving common salts used in desalination technologies, which require even smaller sieves.
Previous research at The University of Manchester found that when immersed in water, graphene-oxide membranes become slightly swollen allowing smaller salts to flow through the membrane along with water, but larger ions or molecules are blocked.
The Manchester-based team has now further developed these graphene membranes and found a strategy to avoid the swelling of the membrane when exposed to water. The pore size in the membrane can now be precisely controlled enabling it to sieve common salts out of salty water making it safe for drinking.
This opens up the potential of providing clean drinking water for millions of people who find it difficult or impossible to access enough clean water sources. By 2025 the UN has predicted that 1.2 billion people, or 14% of the world’s population will encounter water scarcity.
This graphene technology could revolutionise water filtration across the world, in particular in countries, which cannot afford large-scale desalination plants.