The role of nanominerals and mineral nanoparticles in the transport of toxic trace metals: Field-flow fractionation and analytical TEM analyses after nanoparticle isolation and density separation

Autor(en)

Thilo Hofmann, Frank von der Kammer, Kelly Plathe, Martin Hassellov, Michael F. Hochella, Johnnie Moore, Mitsu Murayama

Abstrakt

Nanominerals and mineral nanoparticles from a mining-contaminated river system were examined to determine their potential to co-transport toxic trace metals. A recent large-scale dam removal project on the Clark Fork River in western Montana (USA) has released reservoir and upstream sediments contaminated with toxic trace metals (Pb, As, Cu and Zn), which had accumulated there as a consequence of more than a century and a half of mining activity proximal to the river’s headwaters near the cities of Butte and Anaconda. To isolate the high-density nanoparticle fractions from riverbed and bank sediments, a density separation with sodium polytungstate (2.8 g/cm3) was employed prior to a standard nanoparticle extraction procedure. The stable, dispersed nanoparticulate fraction was then analyzed by analytical transmission electron microscopy (aTEM) and flow field-flow fractionation (FlFFF) coupled to both multi-angle laser light scattering (MALLS) and high-resolution, inductively coupled plasma mass spectrometry (HR-ICPMS). FlFFF analysis revealed a size distribution in the nano range and that the elution profiles of the trace metals matched most closely to that for Fe and Ti. aTEM confirmed these results as the majority of the Fe and Ti oxides analyzed were associated with one or more of the trace metals of interest. The main mineral phases hosting trace metals are goethite, ferrihydrite and brookite. This demonstrates that they are likely playing a significant role in dictating the transport and distribution of trace metals in this river system, which could affect the bioavailability and toxicity of these metals.

Organisation(en)

Externe Organisation(en)

Virginia Polytechnic Institute and State University , University of Gothenburg, Montana State University–Northern

Journal

Geochimica et Cosmochimica Acta

Band

102

Seiten

213-225

Anzahl der Seiten

13

ISSN

0016-7037

DOI

https://doi.org/10.1016/j.gca.2012.10.029

Publikationsdatum

2013

Peer-reviewed

Ja

ÖFOS 2012

210006 Nanotechnologie, 104002 Analytische Chemie, 104023 Umweltchemie, 105904 Umweltforschung

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/c74a2617-6479-415c-811e-7779f2cc4440