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.
|Number of pages||12|
|Journal||Environmental Science and Technology|
|State||Published - Feb 4 2020|
Bibliographical noteFunding Information:
This material is based upon work supported by the National Science Foundation (NSF) and the Environmental Protection Agency (EPA) under NSF Cooperative Agreement EF-0830093 and DBI-1266252, Center for the Environmental Implications of NanoTechnology (CEINT). Any opinions, findings, conclusions, or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF or the EPA. This work has not been subjected to EPA review, and no official endorsement should be inferred. A portion of this research was performed using resources of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, and was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357 and the Canadian Light Source and its funding partners. Portions of this work were performed at the Stanford Synchrotron Radiation Lightsource (SSRL) on beamline 11-2, a Department of Energy supported facility. We thank the beamline scientists Dale L Brewe at APS (BL 20-ID) and Ryan Davis at SSRL (BL 11-2) for their support. Other portions of this work were performed using shared facilities at the Virginia Tech National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth), a member of the National Nanotechnology Coordinated Infrastructure (NNCI), supported by NSF (ECCS 1542100). The authors also thank S. Shrestha for analytical support; Christina Bergemann, Ethan Baruch, Joseph Delesantro, Eric Moore, Matthew Ruis, Erin Vanderjeugdt, Samuel Mahanes, Henry Camp, Jennifer Rocca, Antoine Curinier, Bradley Shewmaker, Lizzy Stokes-Cawley, Mathieu Therezien, Brooke Hassett, Medora Burke-Scoll, Meredith Frenchmeyer, and Belen de la Barrera for their help during the set up of this experiment, lab analyses, and numerous field workdays.
Copyright © 2020 American Chemical Society.
ASJC Scopus subject areas
- Chemistry (all)
- Environmental Chemistry