New technique to better extract uranium from seawater

An ultra-high-resolution technique used for the first time to study polymer fibres that trap uranium in seawater may lead to better methods to harvest this fuel for nuclear reactors, says a study.

The findings showed that polymeric adsorbent materials that bind uranium behave very differently than what scientists had believed.

"Despite the low concentration of uranium and the presence of many other metals extracted from seawater, we were able to investigate the local atomic environment around uranium and better understand how it is bound by the polymer fibres," said lead researcher Carter Abney from US Department of Energy's Oak Ridge National Laboratory.

Surprisingly, the spectrum for the seawater-contacted polymer fibres was distinctly different from what was expected based on small molecule and computational investigations.

"Rather than interacting with just one amidoxime, we determined multiple amidoximes would have to cooperate to bind each uranium molecule and that a second metal that is not uranium also participates in forming this binding site," Abney said.

An amidoxime is the chemical group attached to the polymer fibre responsible for binding uranium.

The researchers plan to use this knowledge to design adsorbents that can harness the vast reserves of uranium dissolved in seawater.

The findings appeared in the journal Energy & Environmental Science