Graphene is the wonder material that can literally be used in everything. One of its many uses is filtering water and it might be the most beneficial one. A team of Australian scientists has demonstrated exactly how much potential graphene has to purify water as it made water from Sydney Harbour drinkable in just one step.
This new water filter system is being called Graphair. It was developed last year by a team at CSIRO. Normally, graphene is made using an energy-intensive process of chemical vapour deposition onto metal substrates. However, Graphair is made from soybean oil, an inexpensive and renewable material.
The team behind this new study used a water filter commercially available and coated it with a thin film of Graphair, which contains nano-channels that block contaminants while allowing water to pass through. Sydney Harbour has very heavily polluted water and to put the new system to the test, water from the Sydney Harbour was used. The water was passed through these filters and it was found that the Graphair filters were able to purify the water to drinking standards in just one go.
“In Graphair we’ve found a perfect filter for water purification,” says Dong Han Seo, lead author on a paper describing the project. “It can replace the complex, time consuming and multi-stage processes currently needed with a single step. All that’s needed is heat, our graphene, a membrane filter and a small water pump.”
The new filters were also seen to keep their filtration rates high for a longer period of time. The problem regular filters face is the building up of unwanted material on the membrane and slowing down the rate of water passing through. The Graphair filters did not have this problem.
The researchers are hoping to start field trials of the new water filters in developing countries next year and believe that this technology can be scaled up to clean a town’s water supply and could be used to filter sea water on a large scale to solve the clean water problem in the world.