UK researchers have developed a sieve that is able to remove salt from seawater, therefore making it drinkable.
Scientists from the University of Manchester developed the graphene-based sieve, and are able to filter out the salt by virtue of precisely controlling the sieve’s pores. It is believed that this development, revealed yesterday in the journal Nature Nanotechnology, could help developing countries in which drinking water is difficult to access. The UN has predicted that 14 per cent of the world’s population, roughly amounting to 1.2 billion people, will have trouble accessing clean water by the year 2025.
Graphene, which was first created at the University of Manchester back in 2004, is an allotrope of carbon that takes the form of a hexagonal lattice, with one atom forming each vertex. 200 times stronger than steel, graphene is also notable for its ability to conduct both heat and electricity, with it almost being almost completely transparent. Although unintentionally used in small quantities for years, Andre Geim and Konstantin Novoselov of the University of Manchester rediscovered it and characterised it, which won the pair the Nobel Prize in Physics in 2010.
Researchers at the university had previously learned that when immersed in water, graphen-oxide membranes would become swollen and block larger pieces of salt from passing through. The new research has now led them to discover how to prevent the membrane from swelling when making contact with water, allowing the salt to be removed from seawater and filtering out clean, drinkable water in the process.
The graphene sieve could help developing countries with minimal access to clean water. (Image Credit: Barcroft Media / Getty Images)
“Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology”, said the University of Manchester’s Professor Rahul Raveendran Nair. “Realisation of scalable membranes with uniform pore size down to atomic scale is a significant step forward and will open new possibilities for improving the efficiency of desalination technology.”
He continued: “This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes.”
Desalination technologies are receiving further investment as climate change continues to reduce clean water supplies across the globe, though desalination plants cost too much money for many of the countries that need them the most. As such, it is hoped that the graphene sieves will help provide a cost-saving alternative.