Scientists invent a way to purify water using only plasma gas. Their method involves the ionization of air bubbles. Then once you have a bubble of plasma soup, popping it can release the electrified mass back in to the water for purification.
Ph.D. candidate Ryan Gott and his professor Dr. Xu originally worked together on Gotts master thesis involving plasma based satellite propulsion, which has quickly become a growing topic of interest among the scientific community. The Momentus water plasma engine for example heats up water until it forms an ionized vapor of oxygen and hydrogen that can be expelled as a fuel.
Now the two researchers are applying their knowledge of plasma science to water purification. As you may have guessed by now – plasma, the fifth state of matter, is an extremely useful multi-faceted substance that can be employed for a variety of applications including satellite propulsion, sterilizing medical equipment, slowing the decay of produce and treating various diseases.
The problem with water purification using the pre-stated method however, is that it is much more difficult to perform at full scale.
“Plasma at atmospheric pressures likes to stay as small as possible in small volumes,” says Dr. Gabriel Xu, an associate professor in the Department of Mechanical and Aerospace Engineering at The University of Alabama in Huntsville (UAH).
“So getting it larger is a decent challenge.”
Luckily for Xu and Gott, they’ve recently received a five year, 20 million dollar grant from the National Science Foundation that will help them develop the technology even further. Water pollution is a growing concern among environmentalists due to it’s devastating impact on wild-life and drinking water. By coming up with advanced methods for purification scientists can make the world a better place for all forms of life, including ourselves.
With the new grant Dr Xus Plasma and Electrodynamics Research Lab will be fitted with the necessary equipment to expand operations while his PHD student Gott will receive funding from the Alabama EPSCor Graduate Research Scholars Program
“Our focus is on developing low-temperature plasma water-purification technology for three applications,” says Dr. Xu.
“The first is manned space travel, the second is chemical and industrial cleanup, and the third is in developing countries where water sources may be polluted with bacteria.”
Dr Xu invented an atmospheric pressure plasma jet that will come in handy for this particular project. By pumping a propellant gas such as argon or helium through a tube where it is then ionized, eventually making contact with water and transforming some of the hydrogen dioxide in to OH radicals that help purify everything.
“I’m still working on improving the design, but we have the basic plasma technology,” says Gott.
“What we’re trying to do now is understand how changing the power operating conditions, gas flow rate, and tube size can affect the size of the plasma plume by studying the production of OH radicals using optical emission spectroscopy.”
“We’re doing pretty well so far using a 3-D printer to quickly and cheaply test different channels and designs,” says Dr. Xu, adding that, at present, they are capable of creating a 2 inch wide and ¾ inch thick “sheet” of plasma. After that, says Gott, “we’ll study the interaction between the plasma and the water and the air, and figure out how we can best shape it to suit our needs.”
Other new and emerging forms of water purification include boiling water with solar power to create super-heated steam. Then there’s the handheld Neatjug which uses a hand-powered lever to charge an ultraviolet bulb, purifying water from the inside. You also have other forms of solar powered water purification that fit right in to transport crates, which would otherwise create pollution upon disposal. There are plenty of complementary technologies as well including acoustic levitation of water droplets for contaminate detection. Getting real old school we also have the modern twist on ancient Egyptian methodology that utilizes a carbon dipped paper monolith surrounded by a pool of water.
cover photo: Ryan Gott by Michael Mercier | UAH