Sawdust Tested as Oil Spill Cleanup MaterialEngineering360 News Desk | December 15, 2016
Effectively responding to oil spills in Arctic waters requires developing cleanup materials and techniques tailored for icy, turbulent conditions.
Sawdust, chemically modified by researchers from the U.S. Department of Energy's Pacific Northwest National Laboratory (PNNL), demonstrates what is reported to be exceptional oil-attracting and buoyant characteristics that researchers say are ideal for remediating oil spills in these environments.
The nontoxic material absorbs up to five times its weight in oil and stays afloat for at least four months.
The researchers focused on wood flour, a woodworking byproduct, which is often used to make wood composites. Attaching vegetable oil components onto its surface transforms the wood flour into oil-grabbing, hydrophobic, bleached powder. Including oil-eating fungi and bacteria to the powder's surface is also being tested so any left-behind material could break down oil over time.
After a thin layer of the substance is sprinkled over oil on the water’s surface, the material immediately starts soaking up oil, creating a concentrated and solid slick that stays afloat. The oil-soaked material can either be burned or retrieved.
The team is using PNNL's Arctic simulation lab in Sequim, Wash., to evaluate the material in icy waters. Ice slush forms on the surface of water that circulates inside a 290-gallon raceway pond placed inside a customized shipping container. Tests have shown the material's water-repellent nature prevents ice from forming on it, allowing it to soak up oil and remain at the surface.
Researchers are also testing how well the material performs in controlled burns. Early results indicate a small amount of material enables burning of both thin and thick layers of spilled oil.