04-04-2017

New nanotech filtration makes seawater affordably drinkable

Earth.com staff writer

Clean, safe drinking water is in short supply for up to one billion people in the developing world, according to The Water Project. In addition, climate change is triggering global drought conditions to crisis proportions. And finally, the World Resource Institute estimated in 2015 that 33 nations would be particularly water stressed by 20140. These and other water-scarcity statistics underline why the development of an effective and affordable seawater desalination and filtering process is such welcome news.

The technology consists of a graphene-oxide membrane that acts as a sort of water filter at the atomic level. Its atoms of carbon and water only allow water through, and act as a barrier to the larger salt and particulate atoms, resulting in the relatively fast and easy desalination of seawater and filtration of dirty water for safe drinking and irrigation.

The new graphene filter is an improvement over an earlier version, both created by scientists at the National Graphene Institute at The University of Manchester (TUM) in England.

Wealthy nations can develop large and costly desalination plants, but this new technology could lead to the development of smaller and much more affordable filtration plants that could serve the needs of poorer countries. And since the water flow-through occurs quickly while the nano-particles of salt and waste are effectively screened, the graphene filters can accommodate the needs of large plants where huge volumes of water would flow.

“This is the first clear-cut experiment in this regime,” said TUM Professor Rahul Nair, a study participant. “We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes.”

The study was published today in Nature Nanotechnology.