Desalination plants are expensive and demand large amounts of power to remove salt from sea water. A new invention could replace that. The National Graphene Institute at the University of Manchester, England has announced that their scientists have developed a filter that removes salt from sea water. Previously graphene sheet filters failed because the tiny holes expanded in water to allow the salt to pass.
Graphene-oxide membranes developed at the National Graphene Institute have already demonstrated the potential of filtering out small nanoparticles, organic molecules, and even large salts. Until now, however, they couldn’t be used for sieving common salts used in desalination technologies, which require even smaller sieves.
Previous research at The University of Manchester found that if immersed in water, graphene-oxide membranes become slightly swollen and smaller salts flow through the membrane along with water, but larger ions or molecules are blocked.
The Manchester-based group have 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 be precisely controlled which can sieve common salts out of salty water and make it safe to drink.
Graphene is a form of carbon which in its crystalline form make up diamonds. Graphene on the other hand is 2 dimensional, just one atom thick. It was isolated and characterized by Andre Geim and Konstantin Novoselov at the University of Manchester in 2004 which earned them a Nobel Prize in 2010.
The National Graphene Institute and the Sir Henry Royce Institute are part of an ambitious plan to make Manchester “Graphene City”.
We believe graphene's vast potential will only be realised by creating a critical mass of scientists, manufacturers, engineers, innovators and industrialists. The innovation ecosystem will have at its core the National Graphene Institute and the Graphene Engineering Innovation Centre. Once completed, we will be able to take a graphene application from basic research to finished product. Manchester was the world's first modern industrial city, now we want to establish a Graphene City
If the new filters can be upscaled to industrial or personal use at reasonable cost, it could have very significant effects. Sailors would no longer need to carry supplies of water or large vessels having to run desalination plants using the fuel on board. Isolated coastal communities could have highly efficient desalination plants to improve productivity of their crops as well as drinking water.