Global Challenges/Chemistry Solutions
Confronting Climate Change: Smoke to soak up future oil spills
August 14, 2009
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SummaryExperts estimate that people dump more than 200 million |
Although internationally publicized oil spills like the Exxon Valdez incident highlight the importance of ecological protection and preservation, these disasters aren’t the only environmental challenges due to oil contamination. Complex problems also occur on a smaller-scale. For example, experts estimate that people dump more than 200 million gallons of used oil each year into sewers, streams, and backyards, resulting in a problem that has plagued wastewater treatment plants for decades.
But an answer might be found in a material sometimes referred to as “frozen smoke.” Super-lightweight solids, also known aerogels, could serve as the ultimate sponge for capturing oil from wastewater and effectively soaking up environmental oil spills. From Arizona State University, here is chemical engineer Robert Pfeffer:
“Aerogels are used mainly as an insulator and for architectural structures
like roofs of swimming pools to keep heat in or out. However, they have
another property and that is that they are very hydrophobic, which means
they love organic molecules and repel water. So that gave me the idea of
maybe we could use these aerogels to remove oil and other organic
contaminants from wastewater.”
Robert Pfeffer, Ph.D.
Image courtesy of
New Jersey Institute
of Technology.
Although there are many different sorbent materials for removing used oil, they are often inefficient and expensive. Hydrophobic silica aerogels are highly porous and absorbent materials and seem like excellent sponges, said Pfeffer, who discusses the dire need for such technology:
“Oh, it’s extremely important because there are a lot of industries where
the water becomes contaminated with oil, machine tool industries
petroleum industry, but that isn’t the worst of it. People change the oil in
their car and then without thinking they just dump the oil into the sewer
and it gets into the water system. So it is really a major problem.”
To test the product’s efficiency, Pfeffer and his team packed a batch of tiny aerogel beads into a vertical column and exposed them to flowing water containing soybean oil, simulating the filtration process at a wastewater treatment plant. They showed that the aerogel beads absorbed up to seven times their weight and efficiently removed oil from the wastewater.
“It’s a lot more effective that other sorbents that were being used to
remove organic contaminants from water. There are a whole bunch of
them that people have tried; for example, the most common is granulated
activated carbon, but people have also used vermiculite, bentonite,
organoclay, all sorts of other adsorbents, and the aerogels per unit weight
are much more efficient and will remove much more for example oil than
any of these materials that have been previously used.”
Smart Chemists/Innovative Thinking
Smart chemists. Innovative thinking. That’s the key to solving global challenges of the 21st Century. Please check our full-length podcasts on stopgap [Confronting Climate Change] and permanent solutions [Confronting Climate Change II] to this daunting problem Today’s podcast was written by Michael Woods. I’m Adam Dylewski at the American Chemical Society in Washington.