Frozen Smoke on the Wastewater

Sponge-like substance could help clean up oil spills


It’s no secret that cleaning up an oil spill is a difficult task. When most of us think of oil spills, we think of incidents like the Exxon Valdez accident, which released more than 10 million gallons of oil into the Prince William Sound in 1989. But what we don’t think about are the more than 200 million gallons of used oil that pollute U.S. wastewater every year after being dumped into sewers, streams and landfills.

In a study released in the journal Industrial & Engineering Chemistry Research, scientists believe that aerogel could be the best absorbent available to help remove unwanted oil from our wastewater. Aerogel, or “frozen smoke,” is one of the lightest solid materials in the world, and has an extremely high absorption capacity along with a very low energy consumption rate—making it the ideal “sponge” to use in wastewater treatment plants.

While wastewater contaminated with oil may not seem like a major concern, the authors of the study argue, “Oily wastewater discharged into the environment causes serious pollution problems since the biodegradability of oil is very low and oily wastewater hinders biological processing at sewage treatment plants.”

Scientists tested the filtration capabilities of aerogel by running water mixed with soybean oil through clusters of aerogel granules. The tiny, porous granules were able to absorb nearly seven times their own weight. Additionally, aerogel seemed more efficient at removing the oil than current filtration materials.

Using aerogel to remove oil from water is the most recent application scientists have discovered for this wonder-material. Aerogel has been used as insulation in everything from the Mars Pathfinder Sojourner to coffee thermoses. And with a nickname like frozen smoke, we can only hope to see much more of this material in the future.