Edible dispersant could provide more eco-friendly way to fight oil spills
By David Szondy
August 23, 2012
Some people believe that there’s no problem that peanut butter, chocolate and whipped cream can’t solve. These people could be onto something with news that a team of researchers has developed a new, safer oil dispersant that uses edible ingredients found in the aforementioned trio of treats. The new dispersant could save the lives of thousands of birds and animals caught in environmental catastrophes.
Oil spills are bad news. They can cause untold environmental damage and cleanup costs can run into the tens of billions of dollars. But sometimes the cure can be almost as bad as the disease. The harm caused by oil spills such as the Exxon Valdez disaster or the Deep Horizon blowout isn’t just due to the spilled oil. The chemicals used to contain and remove the oil, called dispersants, are often very toxic and can do their own damage, so their use is often a trade off between two evils. This is particularly the case when hundreds of thousands of gallons of them are used.
Dispersants work on the same principle as detergents. Detergent molecules work by one end of the molecule being hydrophilic or water loving and the other end hydrophobic or water fearing. The hydrophobic end tries to get away from the water molecules while the hydrophilic end tries to go toward them. Because of these conflicting reactions, the hydrophobic end penetrates into any dirt or, preferably, oil in the vicinity while the hydrophilic end is drawn toward the water. This causes the dirt particles to break up and float away in little bubbles of detergent.
A dispersant works in a similar way, though with a number of other ingredients to help the process. An oil slick treated with detergent will break apart into globules that form an emulsion like a brown, nasty mayonnaise. It looks very unpleasant, but by breaking the slick apart, the oil becomes easier to control and dispose of. The problem is that many dispersants are themselves toxic and very harmful to any birds and animals that ingest them. Worse, dispersants can remove the natural oils on a bird or animal’s hair or feathers. This not only makes them more susceptible to cold and death by hypothermia, but they are more vulnerable to having oil redeposited on them, leaving them worse off than before.
The new dispersant was developed by a team led by Lisa K. Kemp and Robert Lochhead from the University of Southern Mississippi, which built on work done in developing home detergents and used of a robotic system to test thousands of variations.
Though it’s exact composition has not been divulged, Kemp says it is made from ingredients "used in common food products like peanut butter, chocolate and whipped cream," that can be ingested by birds and animals. It uses a uses a special polymer used in washing detergent to keep dirt from settling back on clothes, which also keeps oil from redepositing as well. And because the ingredients are common, large quantities can be manufactured quickly. The dispersant has passed out of the prototype stage and is currently awaiting field testing on actual oil spills.
The researchers presented a report on the new dispersant this week at the 244th National Meeting & Exposition of the American Chemical Society.
Source: American Chemical Society