Graphene oxide introduced to simulated wastes coagulated within minutes, quickly clumping the worst toxins, Kalmykov said. The process worked across a range of pH values.
"To see Stepan's amazement at how well this worked was a good confirmation," Tour said. He noted that the collaboration took root when Alexander Slesarev, a graduate student in his group, and Anna Yu. Romanchuk, a graduate student in Kalmykov's group, met at a conference several years ago.
The researchers focused on removing radioactive isotopes of the actinides and lanthanides the 30 rare earth elements in the periodic table from liquids, rather than solids or gases. "Though they don't really like water all that much, they can and do hide out there," Winston said. "From a human health and environment point of view, that's where they're least welcome."
Naturally occurring radionuclides are also unwelcome in fracking fluids that bring them to the surface in drilling operations, Tour said. "When groundwater comes out of a well and it's radioactive above a certain level, they can't put it back into the ground," he said. "It's too hot. Companies have to ship contaminated water to repository sites around the country at very large expense." The ability to quickly filter out contaminants on-site would save a great deal of money, he said.
He sees even greater potential benefits for the mining industry. Environmental requirements have "essentially shut down U.S. mining of rare earth metals, which are needed for cell phones," Tour said. "China owns the market because they're not subject to the same environmental standards. So if this technology offers the chance to revive mining here, it could be huge."
Tour said that capturing radionuclides does not make them less radioactive, just easier to handle. "Where you have huge pools of radioactive materia
|Contact: David Ruth|