Researchers have made a major breakthrough in the field of water desalination, the process of extracting fresh drinking water from salty ocean water.
The latest development involves filters made from a substance called graphene-oxide. The idea is to use graphene-oxide as a kind of sieve, which will allow water molecules to pass through its pores, but will filter out the salts and other solutes that make seawater undrinkable. This kind of filtration is possible because of graphene-oxide’s porous structure.
The use of special porous substances for desalination is not a new idea, but historically there have been major challenges to coming up with an efficient way to implement the concept. Graphene-oxide filters have even been considered in the past, but originally they failed to act as effective filters. This was because graphene-oxide in a wet environment would absorb water and swell up in size, thereby increasing the size of its pores well past the desired threshold, allowing the undesired salts to pass through the filter unchecked.
The new breakthrough, which was announced in Nature recently, involves treating the graphene-oxide with a special resin that prevents it from soaking up water like a sponge. And by preventing absorption, the researchers also prevented the associated swelling, allowing the pores to retain the desired proportions for successful desalination.
It’s all pretty exciting news, especially as more and more regions of the world approach the limit of what their freshwater supplies will bear, with heavily populated regions like California looking at a real possibility that they will run out of fresh drinking water.
In the words of Rahul Nair, the lead researcher of the team at the University of Manchester which made the discovery, “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.” In other words, Rahul Nair is going to get whatever grant money he asks for next year. And rightly so.
All of this is good news for Australia, which relies heavily on desalinated water, which is only natural for a dry country that is “girt by sea”. Anything that improves the efficiency of desalination is great news for future generations of Australians. So whenever you’re having your next glass of water, remember that soon enough it might be coming to you through resin-treated graphene-oxide filters.