Assessing the interactions of metal nanoparticles in soil and sediment matrices - A quantitative analytical multi-technique approach
Hind El Hadri, Stacey M. Louie, Vincent A. Hackley
The impact and behavior of engineered nanomaterials (ENMs) in the environment is an important issue due to their growing use in consumer and agricultural products. In particular, their mobility and fate in the environment are heavily impacted by their interactions with natural particle components of saturated sediments and soils. In this study, functionalized gold nanoparticles (AuNPs - used as model ENMs) were spiked into complex solid-containing media (standard soils and estuarine sediment in moderately hard water). AuNPs were characterized in the colloidal extract (< 1 µm) following centrifugal separation of the non-colloidal phase, using different analytical techniques including asymmetric flow field-flow fractionation and single particle inductively coupled plasma mass spectrometry. Attachment of functionalized AuNPs to the soil particles did not significantly depend on their concentration or surface coating (citrate, bPEI, PVP, PEG). Similarly, UV degradation of coatings did not significantly alter their recovery. Conversely, the presence of natural organic matter (NOM) appears as a key factor in their adhesion to matrix particles, by decreasing the predicted influence of native surface chemistry and functional coatings. A kinetic experiment performed over 48 h showed that attachment is rapid and that hetero-aggregation is dominant. We propose that ENMs will likely remain locally confined in soils and sediments, and that transport away from the point of discharge (or entry) will be considerably limited. This situation could change in matrices where NOM is largely absent or otherwise sequestered.
El Hadri, H.
, Louie, S.
and Hackley, V.
Assessing the interactions of metal nanoparticles in soil and sediment matrices – A quantitative analytical multi-technique approach, Environmental Science Nano, [online], https://doi.org/10.1039/c7en00868f, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=924241
(Accessed May 28, 2023)