Published on January 11th, 2010 | by Tina Casey1
"Swelling Glass" Cleans Polluted Water Like a Sponge
This is the discovery that could put the College of Wooster on the map: glass that swells like a sponge. Put together like a nano-matrix, the new glass can unfold to hold up to eight times its weight. The glass binds with gasoline and other pollutants containing volatile organic compounds but it does not bind with water, so it acts like a “smart” sponge, capable of picking and choosing from contaminated groundwater.
The new material was developed by Dr. Paul Edmiston of the College of Wooster, who formed a new company, Absorbent Materials, to market the new glass under the trademark Obsorb. A number of pilot sites are being tested in the United States, and industrialized countries are not the only ones that stand to gain. Obsorb’s unique properties make it ideal for low tech, low-budget cleanups in developing areas as well.
Swelling Glass, Hydrophobia and Groundwater Pollution
Obsorb is a reactive glass. Unlike conventional glass, it can bond with the chemicals it encounters. However, it is also hydrophobic, meaning that it does not bond with water. At a recent pilot demonstration in Ohio, Obsorb was used in the form of a white powder to suck up a plume of TCE (a volatile organic compound). TCE is particularly difficult and expensive to clean up using conventional means, which is the reason why some contaminated sites are simply shut down, allowing the vapors to dissipate naturally. The process takes decades, so Obsorb could provide a low-cost means of recovering sites more quickly. The venture development group JumpStart Inc. saw the potential and has just committed a $250,000 investment to Absorbent Materials.
Swelling Glass and Low Cost Clean-up
Once full, Obsorb floats to the surface, where it can be skimmed off with something as simple as a coffee filter. After that the pollutants can be retrieved and the glass can be reused hundreds of time. Nanoparticles of iron can also be added to convert TCE or PCE (another volatile organic compound) into harmless substances. As a low cost form of cleanup, swelling glass could provide site remediators with yet another in the growing list of non-conventional cleanup tools along with lactate, vitamin B-12, and even cattails.
Image: Glass by mrhayata on flickr.com.