More than a decade after the biggest oil spill in U.S. history, and as the Coast Guard works to contain a new disaster off the coast of Southern California, experts say surprisingly little has changed in how oil spills are cleaned up.
Many of the same tools and technologies have been deployed to deal with these environmental catastrophes over the past 20 years, but now, two teams of scientists say their reusable sponges can sop up oil at the surface and underwater — in some cases holding more than 30 times their weight — without doing additional harm to the marine environment.
It’s the kind of innovation they say could make oil spill cleanups, like the situation currently playing out off Huntington Beach, not only more efficient but also more effective. An estimated 126,000 gallons of heavy crude leaked from a ruptured pipeline into the Pacific Ocean early Saturday, setting off frantic efforts to prevent the oil from washing up onto the area’s beaches and into its protected marshlands.
“I think a lot of folks don’t realize that when there is an oil spill, in almost all cases, most of the oil is never cleaned up by humans,” said Seth Darling, director of the Center for Molecular Engineering at Argonne National Laboratory in Lemont, Illinois. “We clean up some, and the rest Mother Nature eventually cleans up, though not quickly, and it wreaks havoc on the local environment all that time.”
Darling and his colleagues at Argonne developed a tool called the Oleo Sponge, which is made by altering the same type of foam that is commonly used in seat cushions and mattresses to make it “oleophilic,” which means it can draw in oil without also soaking up water.
At Northwestern University, a team of scientists developed a similar absorbent called the OHM sponge that uses a specially designed magnetic coating to selectively soak up oil in water.
“Oil and water don’t mix well, but when they do, it’s very difficult to remove,” said Vinayak Dravid, a professor of materials science and engineering at Northwestern, who led the research. “We wanted something that could not only suck up oil but could do it very quickly.”
In lab tests, Dravid and his colleagues showed that the OHM sponge could absorb more than 30 times its weight in oil and can be reused more than 40 times without losing its effectiveness.
With both the Oleo Sponge and the OHM sponge, the recovered oil can be used again, which also means less overall waste after spills.
Both Darling and Dravid said their sponges were designed to fill a gap in available technologies to clean up oil spills, offering officials a new way to respond to major incidents like the Deepwater Horizon spill in 2010, when an estimated 210 million gallons of oil spewed into the Gulf of Mexico. While satellite technologies to map and model oil spills have improved greatly since the Deepwater Horizon spill, the processes for cleanup crews on the water and on beaches have remained mostly stagnant.
“Deepwater Horizon should have driven a lot of innovation but didn’t,” said John Pardue, a professor of civil and environmental engineering at Louisiana State University, who conducted research and ran an advisory program for a land trust in Louisiana in the aftermath of the 2010 spill.
He said it’s because resources are typically devoted to studying the spill sites, as well as the effect of leaked oil on the environment and plants and animals in the region, while funding for developing new cleanup tools is usually limited.
“There’s been upgrades in modeling how spills move and how oil affects fish and animals in the deep ocean and marshes, but in terms of response work, there were a few things that have been tried but nothing that rose to the level of something that will be used moving forward,” Pardue said.
Scientists like Darling and Dravid are hoping to change that.
At present, cleanup crews typically use booms to contain oil spills and prevent them from spreading. The oil can then be skimmed off the surface, but this method is less effective in choppy waters, and waves can push oil deeper into the ocean, where it’s much harder to clean.
Another method for removing oil at the water’s surface is to burn it, but there are obvious drawbacks with employing that strategy.
“It does remove a lot of oil from the water, but of course that turns a water pollution problem into an air pollution problem,” Darling said.
Local officials can also spray oil slicks with dispersants, which break oil into smaller droplets that mix more easily with water. The idea is to remove the oil through biodegradation, in which bacteria and other microorganisms naturally feed on the oil and essentially remove it from the environment.
With the Oleo Sponge, Darling said it’s a new type of absorbent that can sop up spills at the surface and when oil has seeped deeper into the water column. And since the sponges can be reused, they are a “greener” alternative to the tools currently available.
In 2017, the researchers tested the sponges in a giant seawater tank in New Jersey and demonstrated that they could collect diesel and crude oil both below and on the water’s surface. The scientists also tested the Oleo Sponge at a natural oil seep off the California coast, near Santa Barbara, to assess how it works in real-world environments.
Darling said the Coast Guard and private companies have expressed interest in the Oleo Sponge. The goal now, he said, is to find a partner to handle manufacturing the sponges at large scales.
With the OHM sponge, Dravid said he expects the technology to be commercially available soon. He added that his team has already sent samples to colleagues in California to help with recovery efforts at and around Huntington Beach.
In addition to cleanup efforts on the water, Dravid and his colleagues are exploring how the OHM sponge can be modified to soak up oil that washes up on beaches or to assist with cleaning up other types of hazardous contamination.
Dravid said he’s eager for his research to have an impact, but it comes with a bittersweet cost.
“It’s odd because on the one hand, we’re excited for the opportunity to show how this technology can make a difference,” he said. “But with oil spills, we’re always sad for the environmental side of things.”