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Mar 9 – 11, 2015
NH Laguna Palace Hotel
Europe/Rome timezone

Insights from a spatially and temporally resolved nanoparticle fate model

Mar 10, 2015, 3:52 PM
24m
Breakout 3 (NH Laguna Palace Hotel)

Breakout 3

NH Laguna Palace Hotel

Viale Ancona, n° 2 30172 Venice-Mestre, Italy Tel: +39 041 829 6111 Fax: +39 848 390 230
Parallel session 4C: Environmental Release, Fate and Exposure 4C Environmental Release, Fate and Exposure

Speaker

Gregory Lowry (Carnegie Mellon University)

Description

We introduce a spatially and temporally resolved mass balance model for sulfidized Ag NP and ZnO NP loadings to the James River Basin in Virginia.  The model includes oxygen-, sulfide-, and temperature-dependent NP and byproduct (ion) transformations, oxic and anoxic sediment layers, and flow-dependent sediment transport. Although it has been generally ignored in NP fate models, surface runoff of land-applied biosolids accounts for roughly a quarter of NP stream loads in our model. Due to daily flow dynamics, NPs were also more mobile than anticipated in the stream, with only ~5-10% of the cumulative stream load remaining in the basin at the end of the simulation. Therefore, metals from NPs will accumulate downstream in estuarine or marine ecosystems.  Spatially variable discharges and stream flows, control predicted environmental concentrations (PECs) in this model.  Previous steady state models or those applying time-constant parameters and processes suggest peak PECs occur during low flows.  We also observe peaks during high flows due to surface runoff.  Unlike sulfidized Ag NPs, ZnO NPs rapidly dissolve.   PECs never exceed USEPA water or sediment guidelines for Ag and Zn, suggesting low risk in this system at estimated current loading levels.

Primary author

Amy Dale (Carnegie Mellon University)

Co-author

Elizabeth Casman (Carnegie Mellon University)

Presentation materials