A team of researchers from the UK invented a graphene-based sieve that can remove salt from seawater. This development in graphene technology could help millions of people across the globe who don't have access to clean and safe drinking water.
The graphene oxide sieve could be extremely efficient in the process of filtering salts. The results of the research conducted by scientists from the University of Manchester were published in the journal Nature Nanotechnology.
Graphene-Based Sieve Filters Seawater
Up until now, there have been challenges in manufacturing graphene-based barriers in large amounts. The researchers solved some of the challenges using a chemical derivative called graphene oxide.
Graphene was first isolated and characterized by a team of researchers from the University of Manchester in 2004. The material has one layer of carbon atoms that are positioned in a hexagonal lattice. Its groundbreaking properties, among which are exceptional electrical conductivity and tensile strength, have turned it into one of the most promising materials for future development.
However, researchers have had difficulties producing graphene in very large quantities. The production of single-layer graphene through existing methods such as chemical vapor deposition is also notably expensive.
At the same time, according to Rahul Nair, lead author of the research, graphene oxide is easy to produce through an oxidation process that can be carried out in the lab.
Previous studies carried out at the University of Manchester showed that, when immersed in water, the graphene oxide membranes become a little swollen, allowing smaller salt molecules to flow through the holes in the membrane along with the water.
The researchers have now made improvements to the membrane, detailing their work in their study. They applied epoxy resin walls on both sides of the graphene oxide membrane, preventing it from swelling when exposed to water. Doing so also allowed them to adjust the pore size in the membrane, which can now effectively work as a sieve to separate salt from water.
Water Scarcity And The Infrastructure Necessary To Overcome It
The effects of global warming keep reducing the water supplies of modern cities, and wealthy countries have started investing in technologies that allow desalination. After the floods in California, many wealthy cities have begun investing in alternative water solutions.
The United Nations expects 14 percent of the world's population to face water scarcity by 2025. Water scarcity already affects every continent.
"Around 1.2 billion people, or almost one-fifth of the world's population, live in areas of physical scarcity, and 500 million people are approaching this situation," notes the U.N. website.
Furthermore, an additional 1.6 billion people, or nearly a quarter of the world's population, suffer from economic water shortage. This situation describes countries that lack the necessary infrastructure to process water from rivers and aquifers.
With the new graphene-based sieve, the world would be able to massively improve water filtration technologies and address water scarcity.