What if you could disperse oil spills in the sea, such as the BP spill in the Gulf of Mexico, with air, sunlight, and an environmentally friendly botanical product?
Those are the ingredients of experiments published today in the journal Photochemical & Photobiological Sciences describing new findings by a UConn chemistry group.
The research, led by Board of Trustees Distinguished Professor of Chemistry Steven Suib, found that by adding a plant-based surfactant to a sample of synthetic seawater mixed with crude oil, pumping in air, stirring the sample and exposing it to ultraviolet light, the oil/water mixture quickly broke down into small particles.
Suib says that an important side benefit of the research was finding that small amounts of toxic metals leached out of the oil in the process. The metals occur naturally in much of the oil found in the U.S., and they degrade the catalyst that is used to convert oil to gasoline.
“It’s not known where these metals come from – they’re very low concentration – but even a small amount can kill a catalyst,” says Suib, who is a catalysis expert.
In two hours of exposure to light, all of the nickel and 77 percent of the iron in the crude oil samples leached out of the oil.
The intent of the experiments was to find out whether crude oil could be dispersed by adding the surfactant, a substance that changes surface character, to an oil/seawater mixture and exposing the mixture to light and air.
The surfactant that was used, a product called VeruSOL Marine 200, is produced in Connecticut by a Bloomfield, CT company, VeruTEK Technologies, Inc. It is derived from a plant and is patented by the company, which markets it as nontoxic, biodegradable, and useful for cleaning oil and fuel from a variety of surfaces.
Crude oil used in the experiments came from two major spills – the 2006 Prudhoe Bay spill in Alaska and the 2010 Louisiana spill. Synthetic seawater was used so that the sample did not contain biological organisms. In the experiments, one gram of surfactant was added to two liters of the oil/water mixture, and oxygen was blown in. The samples were stirred and exposed to various wavelengths of light that simulated the components of solar radiation.
Within 30 minutes of pumping in the air, oil degradation was taking place. After two hours of UV light exposure, the size of the oil/water particles was substantially reduced for both the Prudhoe Bay and the Louisiana oil samples.
“Photodegradation of crude oil components can be an effective process for mitigating some of the damaging impacts resulting from oil spills in the aquatic environment,” the authors wrote. With the availability of modern, efficient UV-visible light sources, the process “may enable economic application of photodetoxification on a large-scale basis,” they said.
Suib and VeruTEK have jointly applied for a patent on the process using the VeruTEK surfactant.
Co-authors with Suib on the Photochemical & Photobiological Sciences paper are two VeruTEK contributors along with PhD candidates Homer C. Genuino and Cecil K. King’ondu, both from Suib’s research group, and undergraduate Dayton T. Horvath, who is a senior honors chemistry major working in Suib’s lab.
The work was supported by a grant from VeruTEK and funding from the U.S. Department of Energy.
Future work on the project will be to further degrade the crude oil after its exposure to sunlight and to study phototoxicity – the effects on the environment of the light-treated water and oil.
Suib, who specializes in catalysis and green chemistry research, was recently named a fellow of the American Chemical Society. He is the 2011 winner of the Connecticut Medal of Science.
To read the paper, go to Http://dx.doi.org/10.1039/c2pp05275j