Materials

Charged graphene foam acts as "uranium magnet" for water purification

Charged graphene foam acts as ...
MIT engineers have shown that graphene oxide foam can be an efficient filter for uranium in drinking water
MIT engineers have shown that graphene oxide foam can be an efficient filter for uranium in drinking water
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MIT engineers have shown that graphene oxide foam can be an efficient filter for uranium in drinking water
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MIT engineers have shown that graphene oxide foam can be an efficient filter for uranium in drinking water
A schematic of the molecular structure of the graphene oxide foam, which is showing promise in removing uranium from drinking water
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A schematic of the molecular structure of the graphene oxide foam, which is showing promise in removing uranium from drinking water

Is there anything graphene can’t do? Researchers at MIT have found yet another use for the over-achieving wonder material, by making a reusable filter out of graphene oxide foam that acts like a magnet for uranium, effectively pulling the radioactive element out of drinking water.

Uranium can leach into water supplies from natural deposits in rock, or through waste from nuclear power plants or mining operations. Once there, it’s invisible to the naked eye and it doesn’t take very high doses to start causing harm to human health.

Enter everybody’s favorite material. Graphene oxide foam was found to be so well-suited to sponging uranium out of water that it became drinkable by EPA standards within hours. Better yet, the foam could be cleaned off and reused multiple times over without losing its efficiency.

To put the material to work, an electric charge is first sent through the foam. This splits the water around it and releases hydrogen, which increases the pH in the area. That in turn induces a chemical change that attracts the uranium ions to the surface of the foam. Strangely enough, the team found that the uranium was actually crystallizing into a previously unknown form of uranium hydroxide.

The graphene oxide foam is able to snare high amounts of the pollutant, and once enough of it has been collected, it can be easily removed by simply reversing the electric charge, causing it to slide right off. The foam is then ready to be reused.

“Each time it’s used, our foam can capture four times its own weight of uranium, and we can achieve an extraction capacity of 4,000 mg per gram, which is a major improvement over other methods,” says Ju Li, lead researcher on the study. “We’ve also made a major breakthrough in reusability, because the foam can go through seven cycles without losing its extraction efficiency.”

The team says that the method is low-cost and could be implemented along different stages of water infrastructure. The filters could also potentially be modified to target other heavy metal pollutants like lead, mercury and cadmium.

The research was published in the journal Advanced Materials.

Source: MIT

2 comments
2 comments
Kpar
Interesting. Can the Uranium be recovered? And what about the other heavy elements mentioned? Seems unlikely to reduce the need for mining these materials, but who knows?
Skipjack
Meh, uranium is not that radioactive and not that dangerous either unless you literally eat it with a spoon...
Total hyperbole there.
What this technology would be more interesting for is for uranium mining from seawater (which contains quite a lot of uranium, actually).