Environmental hydrologist Thomas Boving, assistant professor of geosciences at URI, and colleagues from the University of Arizona, the Colorado College of Mines, and the University of Texas-San Antonio, developed the innovative system to quickly and economically remove a wide range of toxic materials from the ground using a product called cyclodextrin.
"Cyclodextrin is a type of sugar made from corn starch," said Boving, a native of Germany who joined the URI faculty in 1999 and now resides in Richmond. "It’s better than other technologies for cleaning up hazardous materials because it’s non-toxic and leaving it underground for a period of time causes no harm."
Due to the chemical structure of cyclodextrin, many toxic materials like solvents, pesticides, and polycyclic aromatic hydrocarbons are attracted to it. To clean up a site, Boving will inject quantities of cyclodextrin solution into contaminated soil and groundwater. After allowing the material to move through the earth and attract the contaminants, the cyclodextrin will be pumped out of the ground.
The most innovative part of the cleanup process is how the cyclodextrin is recycled. Because of the relative high cost of cyclodextrin, using it just once would make the process uneconomical. But Boving and colleagues from the URI Chemical Engineering Department developed a method of stripping off the contaminants from the cyclodextrin so it can be used again.
Boving said that the grant from the Environmental Security Technology Certification program, a Department of Defense program, will allow him to prove the benefits and advantages of his technology for aquifer cleanup. "No one who has to clean up a site is going to use an unproven system, so this grant will allow us to demonstrate that our system is quicker and more economical than the most commonly used methods today," Boving said.
The Department of Defense controls about 28,000 sites that must be cleaned up, and at least 500 of those contain the contaminants on which Boving’s system works best. In addition, there are thousands of other sites around the country that also need cleaning. The government estimates it will cost about $1 trillion to clean up all of them.
A military installation in Virginia was selected as the field demonstration site for Boving’s technology demonstration. Beginning in May, his team will conduct preliminary testing of the soils and groundwater at the test site and prepare the field study. The actual field test will be done shortly afterward and will continue for three to four months during summer of 2002.
"There is a tremendous amount of work to do to clean up the thousands of toxic sites in the country," he said. "Obtaining the military’s seal of approval for our system is a big step in the right direction for us."