The 2010 Deepwater Horizon oil spill might be the most well known oil spil of the past few years—its impact on the Gulf ecosystem is still playing out—but it's certainly not the only one. From 2010 to 2013 there have been two major spills each year, on average. Getting that spilled oil out of the water is a huge challenge—one engineers are not particularly good at solving.
But now a physicist at Fermilab thinks he's come up with a new way to clean up spilled oil. By scattering iron filings into oil-laden water, Arden Warner found the filings selectively join onto the oil. Then it's just a simple matter of using a magnet to sweep the oily iron filings up up.
Adding iron filings to the ocean poses its own risks, of course. Iron is often a limiting nutrient in coastal ecosystems, and adding too much can cause an algae bloom that quickly uses up all of the oxygen in the water, hampering other animals' ability to breathe. This kind of oxygen depletion, known as anoxia, is already a risk during an oil spill.
But according to Warner's scheme, that shouldn't be such a big issue. Talking to Fermilab, Warner said that the iron filings only need to be in the water for a short while:
It doesn't take long — you add the filings, you pull them out. The entire process is even more efficient with hydrophobic filings.
...You could essentially have a device that disperses filings and a magnetic conveyor system behind it that picks it up. You don't need a lot of material.
If it works, the technique could be a big step up from existing techniques, says David Biello at Scientific American, which rely on chemical dispersants to break up the oil slick.