A new compound containing a plant-based molecule could make crude oil spill cleanup a little easier on the environment, a new study appearing in the 26 June issue of the journal Science Advances suggests.
Deeksha Gupta and colleagues show that the new molecular compound is biodegradable and works just as well as conventional silicone-based oil-herding agents. Silicone-based chemicals are used to corral oil floating on the ocean's surface into a single, thick mass that can then be burned off in a controlled manner. This type of burning, known as in situ burning, has been partially effective at reducing the harmful effects of oil on marine environments.
Although silicone-based chemicals are effective oil herders, they are non-biodegradable and thought to persist in the ocean for years. Gupta and colleagues at The City College of the City University of New York (CUNY) and Tulane University engineered a herder derived from phytol, a naturally abundant molecule that is released into the ocean as part of the chlorophyll molecule made by marine plants. Phytol is a major component of the sea surface microlayer — the layer of seawater immediately underneath surface water.
In lab experiments, the researchers found that the phytol-based herder increased the thickness of crude oil by roughly 1000%, similar to its silicone-based commercial counterpart. And like commercial herders, the green herder's efficiency increased as water temperature became warmer. Preliminary studies indicate that the phytol-based herder breaks down completely or biodegrades within a month as it reacts with water.
This lab experiment shows how the phytol compound might herd oil spills on the open ocean. | Deeksha Gupta/ Science Advances
The phytol-based compound works much like other oil-herding agents, by directing a combination of "water loving" and "oil loving" chemical elements at the edge of the oil slick in a manner that changes the balance of surface tension between the oil and water. This change reverses the oil slick's spread and causes it to retract into a thick mass. The researchers note that the amount of phytol-based herder used in the study was much less than what would be used in the field. Next, they plan to scale up the production of the compound and do further research on its effects on marine aquatic life.
The research was funded in part by BP/The Gulf of Mexico Research Initiative (GoMRI) through the Consortium for the Molecular Engineering of Dispersant Systems (C-MEDS). GoMRI is a 10-year, $500 million independent research program established by an agreement between BP and the Gulf of Mexico Alliance to study the effects of the 2010 Deepwater Horizon oil spill, and the potential associated impact of this and similar incidents on the environment and public health.
In an April 2015 editorial, Science Editor-in-Chief Marcia McNutt, who was the U.S. Geological Survey director during the Deepwater Horizon event, called for a "community of interdisciplinary disaster scientists" that focus their research specifically on crises that severely disrupt the environment or threaten human health.