Drinking water from sea-water
Saturday 8 April 2017
Back in 2010 I wrote a blog, “Sticky tape and a pencil”, about the award of the Nobel Prize (for Physics) to scientists at Manchester University in the UK for their discovery of graphene. The structure of graphene is covered in the core topic 4.3 Covalent structures. Graphene has many potential uses. This month a group working at Manchester University’s National Graphene Institute published a paper in Nature on using graphene as a molecular sieve to obtain drinking water from sea-water. The membranes are actually made of graphene oxide and allow the passage of water molecules, but not sodium or chloride ions. Although free sodium ions are smaller than water molecules, when in aqueous solution they are surrounded by water molecules and these hydrated ions are too large to pass through the membrane. This discovery could have far reaching consequences. One of the problems increasing faced by many people in the world is access to clean drinking water. The use of graphene membranes has the potential to revolutionise water filtration, particularly in those parts of the world where the cost of large scale desalination plants is prohibitive.
Research at the National Graphene Institute, Manchester University, UK.