Conservation Matters January 2013

The Texas Land, Water and Wildlife Connection

TWRI grant recipient develops a new PCB remediation strategy

By Alejandra Arreola-Triana

A graduate researcher has developed a filter made of an innovative material called reactive activated carbon that, when used in aquatic ecosystems, is able to remove and destroy a harmful, toxic pollutant: polychlorinated biphenyl (PCB).

"According to the U.S. Environmental Protection Agency, 10 percent of the sediment underlying the country's surface water is contaminated with toxic pollutants that pose potential risks to fish, wildlife and humans," said Prince Nfdozo, a doctoral student in civil engineering at the University of Texas - Arlington under the guidance of Dr. Hyeok Choi. Nfdozo received a 2011-2012 Texas Water Resources Institute (TWRI) research grant.

"Our research provides tools for managing contaminated sediment in a way that reduces risks to human health," he said. "Residents of areas plagued with problems of sediments contaminated with toxic pollutants can be confident that their contaminated environments can be effectively managed to eliminate or reduce the potential health risks."

PCBs are a class of chemical compounds that were once widely used in transformers, capacitors and other electrical equipment. These chemicals are highly toxic, potentially carcinogenic and can persist in the environment for many years, Nfdozo said.

Remediation of a PCB-contaminated water body is difficult because these contaminants can deposit in aquatic sediments, he said. "These sediments act as long-term sources for the slow release of PCBs to aquatic environment(s)," Nfdozo said.

The traditional remediation strategy is to install an activated carbon layer to sequester PCBs onsite. However, this strategy does not remove all of the PCBs from the site, and the contaminants are still there after remediation, he said.

Using the special filter, which contains iron and palladium nanoparticles, Nfdozo hopes to chemically destroy PCBs and other harmful contaminants. According to Nfdozo, activated carbon can also trap other types of contaminants.

"This strategy can be applied to other contaminants because the iron and palladium nanoparticles can decompose many other chlorine- or fluorine-containing compounds," Nfdozo said.

Nfdozo's research was funded by TWRI with funds obtained through the U.S. Geological Survey as part of the National Institutes for Water Research annual research program. TWRI is the designated institute for water resources research in Texas.

For more information on Nfdozo's research, visit TWRI Research Grants.

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