R.I. Profs Study Oil Dispersants

CLEAN SLATE: URI engineering assistant professor Geoff Bothun, left, and professor Arijit Bose are developing new technologies for cleaning oil spills. (COURTESY CHRIS BARRETT)

(Click to enlarge) CLEAN SLATE: URI engineering assistant professor Geoff Bothun, left, and professor Arijit Bose are developing new technologies for cleaning oil spills. (COURTESY CHRIS BARRETT)

University of Rhode Island professor Arijit Bose and associate professor Geoff Bothun, both chemical engineers, are working on collaborative research projects on potential new oil dispersants, funded by more than $1.4 million in grants from the Gulf of Mexico Research Initiative and other sources.

(From PBN.com / by Rhonda J. Miller) — Bose and Bothun are part of the Consortium for Molecular Engineering of Dispersant Systems. Bose has been on the issue since it, literally, exploded with the Deepwater Horizon disaster in 2010 that spewed 200 million gallons of oil into the Gulf of Mexico.

The dispersant Corexit was used to break up the oil so it could be more naturally consumed by oil-eating bacteria before landing on shore.

Since Corexit was used, some Gulf Coast residents have reported a variety of illnesses, including skin problems, headaches, dizziness and seizures. The results of a study reported in the February 2013 issue of scientific journal Environmental Pollution found that “… when Corexit 9500A and oil are mixed, toxicity increases 52 fold. Results suggest underestimation of increased toxicity due to Corexit application.”

Bose said that, “As soon as the oil spill happened, the National Science Foundation put out a call for rapid grants of $50,000 and a colleague of mine and I wrote a proposal.” They were awarded a grant and “started looking at alternative dispersants a few months after the spill.”

With the $1.4 million in two overlapping, three-year grants from the Gulf of Mexico Research Initiative, Bose is continuing research on dispersants using small particles, or nanoparticles, of carbon black, a chemical produced by Cabot Corp. in Massachusetts, where he did research during a sabbatical from URI. Carbon black is used in such applications as mascara. Carbon black is the soot that comes from a candle when it’s burned.

“We are looking at something conceptually different than Corexit,” said Bose. “Corexit uses soap molecules to emulsify the oil. If you take oil and water and mix it, the oil will separate from the water. But if you add a little bit of soap to the water and shake it, what will happen is it will form little droplets of oil – emulsification. That’s what Corexit did. The idea is that the oil-eating bacteria would grab hold of these little droplets of oil and consume them so it wouldn’t come up to the surface.”

Since Corexit was used, some Gulf Coast residents have reported a variety of illnesses, including skin problems, headaches, dizziness and seizures. The results of a study reported in the February 2013 issue of scientific journal Environmental Pollution found that “… when Corexit 9500A and oil are mixed, toxicity increases 52 fold. Results suggest underestimation of increased toxicity due to Corexit application.”

Bose said that, “As soon as the oil spill happened, the National Science Foundation put out a call for rapid grants of $50,000 and a colleague of mine and I wrote a proposal.” They were awarded a grant and “started looking at alternative dispersants a few months after the spill.”

With the $1.4 million in two overlapping, three-year grants from the Gulf of Mexico Research Initiative, Bose is continuing research on dispersants using small particles, or nanoparticles, of carbon black, a chemical produced by Cabot Corp. in Massachusetts, where he did research during a sabbatical from URI. Carbon black is used in such applications as mascara. Carbon black is the soot that comes from a candle when it’s burned.

“We are looking at something conceptually different than Corexit,” said Bose. “Corexit uses soap molecules to emulsify the oil. If you take oil and water and mix it, the oil will separate from the water. But if you add a little bit of soap to the water and shake it, what will happen is it will form little droplets of oil – emulsification. That’s what Corexit did. The idea is that the oil-eating bacteria would grab hold of these little droplets of oil and consume them so it wouldn’t come up to the surface.”

The research by Bose and his colleagues with carbon black keeps the emulsion stable for a longer time than the soap-like molecules, providing the required month or so it takes for the bacteria to consume the oil.

“What we decided to do was use a particle which is very bio-friendly and had the ability to emulsify oil into little droplets,” said Bose.

“For the bacteria too, it was important to keep the droplets at about 100 microns in diameter,” said Bose. That size is about one-tenth the diameter of human hair, or about the size of a grain of sand, said Bose, whose specialty area of research is in colloids, or small particles suspended in a medium such as oil or water.

“When this oil spill happened, we decided we could leverage our expertise and use these colloid particles like carbon black to emulsify oil,” said Bose. “It turns out it does a beautiful job.”

Bose is collaborating on the grant projects with URI chemistry professor Mindy Levine, who is studying possible ways to convert polycyclic aromatic hydrocarbons, called PAHs, which are considered pollutants, to less toxic forms. URI engineering professor Vinka Oyanedel-Craver, along with researchers from Brown University and the University of Florida, are also doing related research under the two project grants.

Bothun’s research at URI is studying silica, or sand, which he describes as environmentally friendly, as a dispersant.

“We’d love to be able to use something that is considered safe,” Bothun said. “Ultimately it would be great if we could just use silica particles to disperse oil, maybe in place of chemicals.

“What we’re doing is, in large part, possible because we’re working with nanoparticles,” said Bothun, who is director of the Rhode Island Consortium of Nanoscience and Nanotechnology. “These processes that allow an oil droplet to form work well when the particles are small.”

The small particles have potentially big results, on many levels.

“Just conducting this type of research that’s being done at URI and Brown can bring the national spotlight to Rhode Island,” said Bothun. “Everything is global now and we have to think about how to address these bigger issues.”

“GoMRI In the news” is a reposting of articles about GoMRI-funded research (published by various news outlets). The author’s interpretations and opinions expressed in these articles is not necessarily that of GoMRI.