Drinkable seawater?

For the past few years we have heard that graphene, the 2D wonder material invented at the University of Manchester, is going to save us all. Graphene is apparently going to revolutionise lightbulbs, microchips, batteries, solar panels...and lots of other things.

The problems with graphene have so far been mostly ignored. The fact that it is extremely difficult to manufacture in any useful quantities has mostly been overlooked so far with labs and governments across the world seemingly more interested in taking out patents on potential technology than coming up with a reliable production process.

But I digress.

Graphene is clearly a magnificent invention and really, truly does have potential. Many of the claims about it seem overblown, but the majority of them are not. If we can produce graphene in huge quantities then it really could change the world. Today, news broke of another addition to the list of the wondrous effects of graphene we could see in the future: it could allow us to drink seawater.

Access to drinking water is easily one of the most pressing issues which the human race will face over the next century. One in 10 people around the world currently lack access to clean drinking water. That is equivalent to 663 million people, or twice the population of the USA. As our population increases this crisis will only get more severe - and make no mistake, this is a crisis. The global population is growing most rapidly in areas which have the least water which means that the number of people in severe danger is only going one way.

The various oceans of the world cover two thirds of the planet’s surface, but we can’t drink any of the water in them. The salt content in seawater is deadly to us. The human body can only dispose of liquid that is less salty than seawater, meaning that to get rid of the excess salt contained within seawater the body would have to expel more water than it takes in. Dehydration is the inevitable consequence of that, and that is not good for us humans who are mostly made of water.

So how can graphene help? A UK-based research team has created what they are calling a ‘graphene sieve’ which is capable of removing salt from seawater. Using a chemical derivative called graphene oxide, the team from the University of Manchester have successfully created a sort of hexagonal lattice formation of graphene in which the gaps between the strands are less than one nanometre wide. This is too small for salt to pass through but wide enough for water to pass through, leading to the sieve effect and completely desalinating the water which is put through it.

The aforementioned problems with production remain, but there is a goal now and an end product which could feasibly save hundreds of millions of people from suffering and an early grave. The history of engineering is littered with products which existed only as a brilliant theory until someone cracked the code and managed to produce them on a large scale. Aluminium, titanium and clear glass are all great examples of this. If graphene can follow along the same path then the future will start to look a bit brighter.