Clemson researcher could help ease water shortage
A Clemson physicist is simulating the conditions of outer space in order to develop an innovative new tool in water desalination.
Chad Sosolik, an associate professor of physics, is putting strong, thin pieces of graphene under pressure 1 billion times lower than that of the Earth’s atmosphere and shooting ions through them using an electron beam ion trap (EBIT). The low pressure is necessary to create the ions, which only occur naturally in outer space.
The holes the ions create are just big enough to allow water molecules to pass through the graphene, a super-thin and durable carbon sheet, but small enough to keep salt and other molecules out.
Desalination is used across the world, especially in dry climates, to turn salt water into fresh water, suitable for household and irrigation purposes. Reverse osmosis is a common method: essentially pushing water through a membrane. Sosolik’s method may make the reverse osmosis process more efficient and cost-effective.
Desalination as an alternative water source has been a hot topic recently due to an extreme, prolonged drought in California and fears about future effects of climate change. One way to lower the cost of desalination, which can be expensive, would be the use of a high-strength membrane like the graphene Sosolik is using.
“In terms of affordability, this process is as simple as you can imagine … this is exactly like a water filter,” Sosolik said. “It’s nothing more than a filter with holes in it. The water gets through and the salt doesn’t. There’s nothing electronic involved, all you have to do is get one (a sheet of graphene) big enough.”
The energy required to use this type of filter in desalination is “significantly less,” Sosolik said.
The cutting-edge EBIT machine Sosolik is using is one of approximately three functional ones in the U.S., and one of six total in the country. Sosolik got the machine through a federal grant. Using the machine, Sosolik can control the number of electrons in each ion shot at the graphene. Those ions, which are naturally found only in space, attract electrons from the carbon atoms that make up the graphene, creating holes just the right size to let water pass through.
The graphene is extremely thin — only “one atom thick” — but strong enough to hold up against high water pressure. Testing out the science by shooting ions at the graphene is part of the fun, Sosolik said.
“It’s almost like you’re in the army and shooting munitions,” he said.
The EBIT, housed in the basement of Clemson’s Kinard Hall, will not be used just for the desalination research, however. Sosolik said other researchers could use the machine to study radiation, possible cancer treatments and astrophysics.