Differential Reactivity of Copper- and Gold-Based Nanomaterials Controls Their Seasonal Biogeochemical Cycling and Fate in a Freshwater Wetland Mesocosm

Astrid Avellan (1, 2) , Marie Simonin (3, 1) , Steven M Anderson (4, 1) , Nicholas K Geitner (1) , Nathan Bossa (1) , Eleanor Spielman-Sun (1, 2) , Emily S Bernhardt (1, 4) , Benjamin T Castellon (1, 5) , Benjamin P Colman (1, 6) , Jane L Cooper (1) , Mengchi Ho (1, 7) , Michael F Hochella (1, 8) , Heileen Hsu-Kim (9, 1) , Sayako Inoue (1, 8) , Ryan S King (1, 5) , Stephanie Laughton (1, 2) , Cole W Matson (1, 5) , Brittany G Perrotta (1, 5) , Curtis J Richardson (1, 7) , Jason M Unrine (1, 10) , Mark Wiesner (11, 1) , Gregory V Lowry (1, 2)

1 Center for the Environmental Implications of Nanotechnology
2 CMU - Carnegie Mellon University [Pittsburgh]
3 IRHS - Institut de Recherche en Horticulture et Semences
4 Durham University
5 Baylor University
6 MSU - Montana State University
7 Nicholas School of the Environment
8 Virginia Polytechnic Institute and State University [Blacksburg]
9 CEE - Department of Civil and Environmental Engineering [Durham]
10 Kentucky State University
11 Duke University [Durham]

Reliable predictions of the environmental fate and risk of engineered nanomaterials (ENMs) require a better understanding of ENM reactivity in complex, biologically active systems for chronic low-concentration exposure scenarios. Here, simulated freshwater wetland mesocosms were dosed with ENMs to assess how their reactivity and seasonal changes in environmental parameters influence ENM fate in aquatic systems. Copper-based ENMs (Kocide), known to dissolve in water, and gold nanoparticles (AuNPs), stable against dissolution in the absence of specific ligands, were added weekly to mesocosm waters for 9 months. Metal accumulation and speciation changes in the different environmental compartments were assessed over time. Copper from Kocide rapidly dissolved likely associating with organic matter in the water column, transported to terrestrial soils and deeper sediment where it became associated with organic or sulfide phases. In contrast, Au accumulated on/in the macrophytes where it oxidized and transferred over time to surficial sediment. A dynamic seasonal accumulation and metal redox cycling were found between the macrophyte and the surficial sediment for AuNPs. These results demonstrate the need for experimental quantification of how the biological and chemical complexity of the environment, combined with their seasonal variations, drive the fate of metastable ENMs.

Domaines: Sciences de l'environnement

Astrid Avellan, Marie Simonin, Steven M Anderson, Nicholas K Geitner, Nathan Bossa, et al.. Differential Reactivity of Copper- and Gold-Based Nanomaterials Controls Their Seasonal Biogeochemical Cycling and Fate in a Freshwater Wetland Mesocosm. Environmental Science and Technology, 2019, 54 (3), pp.1533-1544. ⟨10.1021/acs.est.9b05097⟩. ⟨hal-02958362⟩