Title: "How Carbon Nanotubes Enhanced the Toxicity of an Organic Pollutant"
Start Date: 03/18/2013 - 12:00pm
End Date: 03/18/2013 - 1:00pm
Fabienne Schwab, Ph.D., Visiting Research Scholar from the Swiss National Science Foundation
Abstract: Carbon nanotubes (CNT) are increasingly manufactured due to their promising technical advantages. Once in environment, CNT may change the distribution, bioavailability, and thus, toxicity of organic pollutants due to their strong sorption properties. In the studies which will presented in this seminar, the interactions of green algae, CNT and a model pollutant (diuron) were systematically quantified. Soot was used as a carbon based reference material, and natural organic matter was added to the CNT suspensions to simulate well dispersed CNT under environmental conditions, opposed to agglomerated CNT suspensions under laboratory conditions.
The results suggest that taking into account the measured dissolved instead of the initial diuron concentration, its effect was stronger in the presence of CNT by a factor of up to 5. The most pronounced increase of diuron toxicity occurred after long-term exposure (24 h), and at low (environmentally relevant) CNT and / or diuron concentrations. All results point to locally elevated exposure concentration in the proximity of algal cells associated with CNT as a cause for the increase in organic pollutant toxicity.