Nadia Ayad from Brazil won Sandvik Coromant’s Graphene Challenge with her innovative idea to use the material in a desalinization solution for ordinary homes.
Pending water scarcity was the impetus for Brazilian Nadia Ayad’s winning entry in the Sandvik Coromant Graphene Challenge, which took place in spring 2016. Ayad, 23, designed a filtration and desalinization device for homes that would make use of graphene to recycle water, reducing both energy costs and the strain on water supplies.
“Water resources are really becoming limited,” she says. “UN studies show that there are areas where in 2040 or 2050 water will be scarce, so there have to be ways to treat water that already exists, so it can be used by the next generation.”
The Graphene Challenge, which ran from April to May 2016, sought to inspire the next generation of engineers by encouraging them to discover innovative and sustainable ideas on how graphene could be used in modern households. Nadia, a Rio de Janeiro native studying material engineering at the Military Institute of Engineering (Instituto Militar de Engenharia), heard about the Challenge and was intrigued. “Graphene was something that we had heard about in class – an amazing material that will likely play a big role in the future because it has very interesting properties.
“I started reading about it and trying to think of a way to apply it,” she says.
“Graphene has always been expensive and thus impractical for use in the home. But I saw articles that said it was getting much cheaper.”
The idea that Nadia submitted for the Graphene Challenge was to use graphene as a filter in a home-based desalinization unit. With the graphene filter, she says, her device would work more quickly than similar existing devices.
As winner of the Graphene Challenge, Nadia will come to Sweden in November to visit Sandvik Coromant’s headquarters in Sandviken and the Graphene Centre at Chalmers University.
Given Brazil’s current economic crisis, many of Nadia’s peers who have graduated in engineering have struggled to find jobs. But her ambition has always been to be an academic, and eventually to specialize in biomaterials and tissue engineering.
“I like the medical field,” she says. “I really want to be able to apply engineering ideas to create products that will really make a difference and will help people overcome diseases that are currently very difficult to treat.”
Nadia is also excited about the role that engineering can play in a future world.
“We know that engineering can be used in many ways, but we also know we must have the support of the population and face a demand for it to become sustainable,” she says. “If you have an awareness of progress and an awareness that progress needs to be sustainable, then engineering has the duty to follow this path. And surely the world will tilt towards being much more sustainable than it is now.”
Nadia Ayad's winning solution
This is how Nadia Ayad described her solution in the Graphene Challenge entry form:
Graphene is turning into the biggest promise in materials science. So far the properties reported are many and exciting: It is stretchable, transparent and super-conductive, and it has the ability to filter gases and liquids a molecule at a time, with great heat and electric conductivity, and to turn light into energy, and it is 200 times stronger than steel by weight. The production costs are also being constantly reduced: Researchers at the University of Glasgow have found a way to produce large sheets of graphene at a cost some 100 times cheaper than the previous production method.
One of the most exciting applications to me, however, is the use of graphene as a filtration device. Researchers at the University of Manchester have published results reporting precise and ultrafast molecular sieving through graphene oxide membranes. While graphene in a dry state creates a vacuum, when graphene with narrow pores is immersed in water, it can readily allow a very rapid flow of two monolayers of water and small ions, much higher than could be explained only through diffusion. With regard to the separation properties, a large capillary force also facilitates the precise permeation of small ions (of less than nine angstroms). However, larger ions are effectively blocked.
This has prompted more research into the potential of graphene as a desalinization membrane. Current methods of desalinization are based on reverse osmosis. Studies have shown that graphene desalinization has a flow that is at least one order of magnitude higher than the best reverse osmosis membranes. This could significantly reduce energy costs in the desalinization process.
With increasing globalization, the planet’s water supplies are becoming limited. It is calculated that about 40 percent of the world’s population lives in water-stressed areas. This number is projected to be about 50–65 percent in 2025. And in 2050, nearly half of the world's population will be living in areas where water is scarce, yet 90 percent of all population growth will occur in those regions.
In the context of a sustainable home, graphene membranes could then be used as a filtration device and in wastewater treatment. It could be used to filtrate rainwater and water from washing machines and from under the sink and make it into drinking water. Also, houses that are close to the ocean could benefit from having graphene membranes for desalinization, reducing even further the costs for delivery of clean water.
Therefore, graphene oxide membranes could be placed in drains in reservoirs of rainwater and also in personalized water treatment plants to reuse the water being used in homes, to reduce the energy spent in water treatment and also to reduce the strain on current water supplies, making graphene a very important material in our efforts to create a more sustainable world.