Impact of Silver Nanoparticles on the Aqueous Environment: Analytical Method Development and Field Experiments
Final Report Abstract
The increasing application of silver nanoparticles in consumer products and their potential release into the environment call for intensive investigation of their toxicity, stability, and fate. In this research project, analytical strategies and methods were developed for the characterization of the nanoparticles in environmentally relevant concentrations. The combination of single particle inductively coupled plasma mass spectrometry analysis and the principle of isotope dilution analysis successfully gave way to the fast and easy size determination of nanoparticles in environmental samples. Laboratory experiments in this research project included a detailed look on potential transformation reactions of silver nanoparticles in diverse aqueous environments. Especially the treatment with ozone, as occurring in advanced wastewater treatment plants, showed how fast the nanoparticles dissolve in water when not stabilized. A whole lake addition at the Experimental Lakes Area in Ontario (Canada) gave insight into the behavior of silver nanoparticle in natural waters. It was found that despite their tendency to dissolve quickly in distilled water, they are mostly stable in lake water. Only small concentrations of dissolved silver indicated that a small fraction of the particles dissolve. Size distribution patterns showed that nanoparticles are present in their original size and distributed through the whole lake, remaining in the aqueous phase. A balancing of silver between water and sediment was not possible, as well as a statement on how much silver is dissolved (due to instrumental detection limits). However, the presence of silver in nanoparticulate form in the aqueous phase will be of great interest regarding its bioavailability and entrance into the food chain of aquatic animals and plants.
Publications
-
Rapid size characterization of silver nanoparticles by single particle ICP-MS and isotope dilution. J. Anal. At. Spectrom., 2014, 29, 1265-1272
Telgmann, L.; Metcalfe, C. D. & Hintelmann, H.
