New Reusable Sponge Material Could Revolutionize Cleanup After Oil Spills
nsnbc : Researchers at Argonne National Lab have developed a sponge material that could revolutionize the cleanup of oil spills, reduce the adverse environmental effects and make it possible to clean up spills more quickly and cheaply – and maybe reduce the need to use toxic chemical solvents.
The new material can soak up 90 times its own weight in oil and it can be reused hundreds of times. Spongy materials have previously been used in absorbent booms but these booms can only soak up between three or seventy times their weight in oil and cannot be reused.
Once used, these booms had to be retrieved and “disposed of” which means that enormous amounts of sorbent materials had to be used for very large oil spills.
The new material created by Seth Darling and colleagues at Argonne National Laboratory in Illinois consists of a foam made of polyurethane or polyimide plastics coated with silane molecules with a “sweet spot” for capturing oil. Too little chemical attraction would render the sponge useless as an absorber, whereas too much would mean the oil could not be released.
In lab tests the team at the Argonne National Lab found that when engineered with just the right amount of silane, their foam could repeatedly soak up and release oil with no significant changes in capacity. The lab tests looked promising, but to determine whether this material could help mitigate the effects of big spills in marine environments the researchers had to carry out a large-scale test.
So, that’s what the team in December 2016. The team constructed an array of square pads of the sponge material measuring 6 square meters. Seth darling said “We made a lot of the foam, and then these pieces of foam were placed inside mesh bags – basically laundry bags, with sewn channels to house the foam.” The arrays were then suspended from a bridge over a large pool designed for practicing emergency responses to oil spills.
Video Courtesy New Scientist
The team then dragged these arrays of sponges behind a pipe spewing crude oil to test the material’s capability to remove oil from the water.
They next sent the sponges through a wringer to remove the oil and then repeated the process, carrying out many tests over multiple days.
The results of the test conducted in December at the National Oil Spill Response Research & Renewable Energy Test Facility in Leonardo, New Jersey haven’t yet been published in peer-reviewed literature.
However, the “concept” has been proven already. Seth Darling said “Our treated foams did way better than either the untreated foam that we brought or the commercial sorbent”.
One of the questions the team would like to investigate is whether the material can perform well under the high pressures of the deep-sea. However, it is already safe to say that it could be used on the surface whether most oil normally floats.
The concept has been proven and Seth may indeed become a “Darling” of environmentalists who remember the devastating effect caused by the dispersion of chemical solvents like Correxit during the Deepwater Horizon oil spill.
CH/L – nsnbc 13.03.2017