This Simple Filter Makes Seawater Safe To Drink
Graphene has the incredible ability to repel water while absorbing all the nasty material, but it's expensive to manufacture. Scientists have discovered a cheaper way to create it with soybean oil.
Updated May 23 2019, 6:50 a.m. ET
Over two billion people in the world don’t have access to safe, clean drinking water. This leads to a lack of proper hygiene, the spread of many diseases, and premature death of kids growing up in developing countries. In order to increase clean water reach, Australian scientists have developed a cheap graphene material that can effectively filter salt and dirt from water.
Graphene is a material that has numerous useful properties, one of them being an ability to repel water. At the same time, it can absorb salt and dirty materials in water, essentially creating a filter. What's the problem? It can be expensive to create the material, and can use a lot of energy.
Scientists at the Commonwealth Scientific and Industrial Research Organization (CSIRO) have developed a cheaper graphene material called “Graphair.” It retains the same properties as traditional graphene, but it’s made out of soybean oil. What's so important about this development? It's both less expensive and more eco-friendly.
In testing the material, researchers put a thin film layer on a commercial-grade water filter. It blocked out 99 percent of the contaminants from Sydney Harbor samples they tested on, even when the layer was dirty. Without the Graphair film, the same filter blocked material at half the rate over a 72-hour period. The end result was filthy water being safe and clean.
"This technology can create clean drinking water, regardless of how dirty it is, in a single step," Dr. Dong Han Seo, one of the scientists on the project, said in a news release. "All that's needed is heat, our graphene, a membrane filter and a small water pump. We're hoping to commence field trials in a developing world community next year.”
Should they be able to scale this product up, the technology could be used for water utility filtration and has the potential to treat industrial wastewater. On a smaller scale, it could be used to enhance household water filters.
Perhaps the best benefit is the potential for it to reach rural areas and developing countries. Since it’s cheap to make, it can provide clean water where it’s completely inaccessible, especially in the worst areas like sub-Saharan Africa and Southern and Eastern Asia. Over 800,000 children under the age of five die annually from diarrhea due to unclean water.
"Almost a third of the world's population, some 2.1 billion people, don't have clean and safe drinking water,” Seo said in the news release. "As a result, millions – mostly children – die from diseases associated with inadequate water supply, sanitation and hygiene every year. In Graphair we've found a perfect filter for water purification.”