In a recent collaborative study conducted between university researchers from Rice and Kazan, it was discovered that cleaning up the radioactive mess that we have created is a lot easier than was previously thought.
The research found that by using two relatively inexpensive materials, a large percentage of radioactive contaminants could easily be removed from water using column filtration, which is both inexpensive, and scalable.
One of the innovative materials that was studied is Oxidatively Modified Carbon 1, or OMC1, which was created from coke-derived C-seal F.
The researchers found that once modified, OMC1 was highly efficient at absorbing radioactive metal cations, like cesium and strontium. C-seal F is currently used as an additive to oil drilling fluids and is inexpensive and widely available.
The other component of the filter is a naturally occurring carbon-heavy mineral called shungite, which is found in plentiful quantities in Russia. Once modified by the researchers the shungite based material was called OMC2.
OMC1 acted as a better filter overall, achieving an absorption rate of 83% of the cesium and 68% of the strontium when 800 milligrams was introduced to 100 milliliters of water.
OMC2 was slightly less effective, as it was able to remove 70% of the cesium and 47% of the strontium under the same conditions.
One interesting thing about shungite, is that in its raw state it acted as a great filter, the refined version gained little in efficiency and raw shungite has been used as a water filter by native populations since pre-history.
Previous research done by another group of scientists had shown that a material called graphene oxide could trap lighter radioactive elements, but it struggled to absorb heavier elements like cesium. It was also expensive to manufacture, and the creation of graphene oxide in the quantities needed to deal with a disaster like Fukushima was a concern.
When the two OMC’s were introduced to a column filtration test, they were able to remove almost 93% of the cesium and 92% of the strontium in the water on the first pass. The heavy radioactive elements were then able to be contained and isolated by the scientists.
The use of carbon-based materials gives this method a huge advantage over many other types, as carbon that has been contaminated with radiation can be burned in a nuclear incinerator to save on space once it has been reduced in size.
It is reassuring to see that there is some remediation available to one of the most irresponsible uses of human ingenuity ever.
Hopefully these new materials can help to stem the flood of highly toxic radiation into the Pacific Ocean, and mitigate the environmental nightmare that mid 20th century nuclear reactor design has shown itself to be.