HR: 0800h
AN: H51G-0851    [Abstracts]
TI: Transport and Fate of Titanium-Dioxide Nanoparticles in Heterogeneous, Unsaturated Porous Media
AU: * Hoggan, J L
EM: hoggan@ou.edu
AF: University of Oklahoma, 202 W. Boyd St., Room 334, Norman, OK 73019, United States
AU: Chen, L
EM: Lxchen@ou.edu
AF: University of Oklahoma, 202 W. Boyd St., Room 334, Norman, OK 73019, United States
AU: Sabatini, D A
EM: sabatini@ou.edu
AF: University of Oklahoma, 202 W. Boyd St., Room 334, Norman, OK 73019, United States
AU: Kibbey, T C
EM: kibbey@ou.edu
AF: University of Oklahoma, 202 W. Boyd St., Room 334, Norman, OK 73019, United States
AB: The increased production and use of manufactured nanoparticles presents concerns for human and environmental health, especially in light of the recently discovered cytotoxicities of many nanoparticles. Nanoparticles can exhibit unique chemical and physical properties compared to their bulk counterparts, which may influence their mobility in the subsurface. Previous studies have shown that the vadose zone plays an important role in solute transport, and may entrap colloids at the air/water interface. Aquifer recharge may release colloids from the vadose zone into the saturated zone, where the potential for mobility is greater. To date, little information has been reported regarding the exchange of nanomaterials between the vadose and saturated zones. Recent laboratory experiments have examined the effects of macro-heterogeneity in the vadose zone on the transport of titanium-dioxide nanoparticles. A custom designed, large-scale, one-dimensional vertical column has been used to study natural infiltration and drainage of nanoparticle suspensions in unsaturated soils. It has been observed that the spatial configuration of the hydraulic properties of a heterogeneous soil profile can dramatically influence the mass of titanium-dioxide nanoparticles retained in the vadose zone. Results of experiments and corresponding flow and transport model simulations will be discussed, with an emphasis on the implications for nanomaterial mobility and associated risk.
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1847 Modeling
DE: 1875 Vadose zone
SC: Hydrology [H]
MN: 2007 Fall Meeting