Carbon based filters offer hope for Fukushima clean up
8 Feb 2017 by qwbdchbctt.d qwbdchbctt.d
Researchers from Russia and the US have discovered a method to extract radioactive elements from contaminated water.
Researchers from Russia and the US have discovered a method to extract radioactive elements from contaminated water.
This finding offers hope of purifying vast amounts of radioactive water stored after the 2011 Fukushima nuclear plant accident by using oxidatively modified carbon (OMC). The treated carbon is both inexpensive and highly efficient at absorbing radioactive metal cations.Team leader Professor James Tour, from Rice University, said: “Just passing contaminated water through OMC filters will extract the radioactive elements and permit safe discharge to the ocean. This could be a major advance for the clean-up effort at Fukushima.”
The researchers believe OMC can also trap common radioactive elements found during oil extraction, such as uranium, thorium, radium, caesium and strontium. It is formed from two natural types of carbon – C-seal F, an inexpensive, coke-derived powder and shungite, found mainly in Russia.
Rice University had been involved in previous research published in Solvent Extraction and Ion Exchange, that demonstrated the removal of radionuclides using graphene oxide, but this new research suggests OMC is much more cost-effective.
Professor Tour said: “In the second study, we learned we can move from graphene oxide, which remains more expensive and harder to make, to really cheap oxidised coke and related carbons to trap these elements. Carbon that has captured the elements can be burned in a nuclear incinerator, leaving only a very small amount of radioactive ash that's much easier to store.”
OMC1 – produced from coke – was found to be better at removing both caesium and strontium at contaminated water than OMC2 – produced from shungite. More than 80% of caesium and more than 60% of strontium was removed in 100ml radioactive water when filtered by 800mg of OMC1. When combined with OMC2 and used in column filter tests, more than 90% of both caesium and strontium from 100ml of contaminated water, was absorbed in a single pass.
The study was published in Carbon.
