Environmental fate of nanoparticles depends on properties of water carrying them

Nanomaterials in the environment

Laboratory equipment used to study the transport and retention of C60 nanoparticles in water. Click here for more information.

The fate of carbon-based nanoparticles spilled into groundwater – and the ability of municipal filtration systems to remove the nanoparticles from drinking water – depend on subtle differences in the solution properties of the water carrying the particles, a new study has found.

In slightly salty water, for example, clusters of Carbon 60 (C60) would tend to adhere tightly to soil or filtration system particles. But where natural organic compounds or chemical surfactants serve as stabilizers in water, the C60 fullerene particles would tend to flow as easily as the water carrying them.

“In some cases, the nanoparticles move very little and you would get complete retention in the soil,” said Kurt Pennell, a professor in the School of Civil and Environmental Engineering at the Georgia Institute of Technology. “But in different solution conditions or in the presence of a stabilizing agent, they can travel just like water. The movement of these nanoparticles is very sensitive to the solution conditions.”

Research into the transport and retention of C60 nanoparticles was reported April 11 in the online version of the American Chemical Society journal Environmental Science and Technology and will be published later in the print edition. The research was funded by the U.S. Environmental Protection Agency.

Comparatively little research has been done on what happens to nanoparticles when they are released through accidental spills – or when products containing them are discarded. Researchers want to know more about the environmental fate of nanoparticles to avoid creating problems like those of polychlorinated biphenyls (PCBs), in which the harmful effects of the compounds were discovered only after their use became widespread.