Nano-CarboScavengers: Safer Alternative for Oil Spill Cleanup

Oil spills have been reduced drastically since the 1970s (from 200 thousand tonnes to 7,000 tonnes) with advancements in the shipping industry and improvements in equipment, safety, and new policies and regulations. Even with these advancements, there is still a need for spill cleanup. Traditional cleanup methods such as booms and skimmers or chemical dispersants leave behind thin films that can cause considerable ecosystem damage. Furthermore, the chemical dispersants can be just as toxic, if not more toxic, to the environment as the oil that it seeks to treat.

To improve on current cleanup methods, a collaborative team of researchers from Carle Foundation Hospital, Northwestern University, and the University of Illinois (Department of Bioengineering, Illinois Applied Research Institute, and Illinois Sustainable Technology Center) developed a non-toxic bio-based nanoparticle as an alternative to traditional cleanup methods for oil spills. Called Nano-CarboScavengers (NCS), the nanoparticles are made by microwaving agave syrup or clover honey for a few minutes to form the carbon-based nano-structure. Then two hydrophobic molecular layers develop around the carbon core forming two pockets. When NCS are sprinkled over the spill, the pockets fill with oil or oil derivatives such as gasoline, leaving the water behind. Filled NCS clump together and can be easily removed using a fine mesh filter.

Laboratory tests show that NCS are more than 80% effective in removing oil that was introduced into water samples in the laboratory. In the natural environment, NCS are expected to be even more effective when they work in combination with naturally occurring bacteria that break down oil into non-hazardous components.

After clumped NCS are filtered out of the natural environment there may be some residual NCS inadvertently left behind. Thus, the research team checked to make sure that NCS would not be harmful to animals and humans who may accidentally ingest NCS. Laboratory studies showed that NCS can be completely digested in seven days in animals and humans and can even be broken down by the slower metabolisms of plants in eight weeks.

In addition, environmental impacts from transportation of NCS may be less than current alternative methods of oil removal. NCS are the first of their kind to be a non-liquid oil-scavenging solution. Being a powder, it weighs significantly less than liquid alternatives and thus has a lower transportation burden. Furthermore, there may be an opportunity for some financial recovery from the spill. The team is investigating the quality of the oil recovered with NCS for its potential to be used in a variety of areas.

Other applications of NCS may include treatment of legacy pollutants, emerging contaminants, and biomass-to-energy wastewaters.

Funding for this project came from the Institute for Sustainability, Energy, and Environment at the University of Illinois. Read about a modified NCS that removes pharmaceuticals from water.