University of Strathclyde researcher has developed a nano-filter that could desalinate sea water and transform into more and more fresh drinking water.
Jason Reese, Weir Professor of Thermodynamics and Fluid Mechanics, and his research group say that carbon nanotubes (CNTs) - essentially sheets of one-atom thick carbon rolled into cylinders - can transform abundant seawater into pure, clean drinking water.
Their technique is based on the process of osmosis - the natural movement of water from a region with low solute concentration across a permeable membrane to a region with high concentration.
But just as with most existing water-desalination plants, Reese's technique actually uses the opposite process of 'reverse osmosis' whereby water moves in the opposite direction, leaving the salty water clean.
Reese has shown that CNTs can realistically expect to have water permeability 20 times that of modern commercial reverse-osmosis membranes, greatly reducing the cost and energy required for desalination.
Additionally, CNTs are highly efficient at repelling salt ions, more so because specific chemical groups can be attached to them to create a specific 'gatekeeper' function.
"The holy grail of reverse-osmosis desalination is combining high water-transport rates with efficient salt-ion rejection. While many questions still remain, the exciting potential of membranes of nanotubes to transform desalination and water-purification processes is clear, and is a very real and socially progressive use of nanotechnology," said Reese.
The finding appears in the current issue of Physics World.