UNIVERSITY OF GEORGIA Savannah River Ecology Laboratory NEWS RELEASE
Contacts: Jane M. Sanders: (803) 725-9724 Beeper: (706) 785-8289
Email: [email protected]
Marie Fulmer; (706) 869-9703 Beeper: (803) 867-0284
Email: [email protected]
FOR RELEASE APRIL 24, 1997
Groundwater remediation technology may save millions in cleanup costs
AIKEN, S.C. -- A pending patent, filed for by two researchers at the University of Georgiaπs Savannah River Ecology Laboratory, could reduce cleanup costs by millions of dollars at U.S. Department of Energy facilities across the country and make the most commonly used groundwater remediation technology process much more effective.
Drs. Paul Bertsch and John Seaman believe the implications of their research at the Energy Department's Savannah River Site (SRS) near Aiken, S.C., could also mean huge savings to American industries that are faced with lengthy cleanup projects, they said. The researchers expect upcoming field tests on a groundwater remediation technology they have developed will prove their projected savings in cleanup costs, they said.
Laboratory studies have also suggested that this technology is applicable to contaminated sites ranging from South America through the southeastern U.S. to the Upper Coastal Plain of the Mid-Atlantic states, where soil and groundwater conditions are similar, they said.
Traditionally, cleanup workers have used a process known as "pump and treat" to remediate groundwater contamination, said Dr. Bertsch, a senior researcher at the Ecology Laboratory. In this process, the heavy metals, industrial solvents and radioactive elements that have contaminated the groundwater at SRS and elsewhere, are pumped out with the groundwater, and then treated before the decontaminated water is returned to the aquifer upstream of its original location. Yet, most of the contamination is bound up in the clay fraction of the aquifer and not readily extracted during pumping.
The problem, the researchers said, is that the contaminants don't flow freely with the water. They cling stubbornly to the clays and sands of the ground. Because of that, the typical pump and treat process leaves much of the contamination in the ground, requiring a constant, costly cycle of pumping and treating, Drs. Bertsch and Seaman said. At many sites, current predictions indicate it could take decades to clean up contaminated groundwater with conventional pump and treat methods. Cutting that time in half could not only save billions of dollars, but probably prevent dangerous contaminants from reaching vital water sources, the researchers said.
The Ecology Laboratory researchers' new technology, known as Selective Colloid Mobilization (SCM), employs a class of environmentally benign chemical compounds to actually mobilize tiny contaminant-carrying particles called colloids. The SCM process suspends the natural clays within a contaminated aquifer so that they may be extracted along with the contaminants that are adsorbed to them, thus increasing the efficiency of remediation.
The SCM process also simplifies the treatment of the contaminated groundwater before it can be returned to the subsurface, they said. Drs. Bertsch and Seaman's system is designed to extract contaminants with the clay fraction of the aquifer, while traditional pump and treat systems treat only the easily removed contaminants, they said.
In laboratory experiments, the SCM method has proved effective at mobilizing contaminant-carrying colloids, and Drs. Bertsch and Seaman believe field experiments will support this and also demonstrate that SCM reduces the growth of unwanted bacteria around the wells, they said.
The two scientists are confident their approach will at least double the amount of contaminants that workers can extract from the soil over a given time period, they said.
The next step, scheduled for the summer of 1998, is to take their experiment to a field test somewhere at SRS. Even with this stage of testing yet to occur, several industries, including the kaolin mining industry, have approached the two scientists about their chemical answer to enhancing colloid extraction, they said.
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FOR MORE INFORMATION: To conduct interviews, you may contact the researchers directly, or seek assistance from one of the public information officers listed above.
1. Dr. Paul Bertsch: (803) 725-5637; or email: [email protected] 2. Dr. John Seaman: (803) 725-3981; or email: [email protected]
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