title: Two dimensional transport characteristics of surface stabilized zero-valent iron nanoparticles in porous media.
abstract: Zero-valent iron nanoparticles (INP) were synthesized and stabilized using poly acrylic acid (PAA) to yield stabilized INP (S-INP). A two-dimensional physical model was used to study the fate and transport of the INP and S-INP in porous media under saturated, steady-state flow conditions. Transport data for a nonreactive tracer, INP, and S-INP were collected under similar flow conditions. The results show that unstabilized INP cannot be transported into groundwater systems. On the other hand, the S-INP can be transported like a tracer without significant retardation. However, the S-INP plume migrated downward as it moved horizontally in the physical model, indicating that small density gradients have significant influence on two-dimensional transport. The variable-density groundwater flow model SEAWAT was used to model the observed density-driven transport patterns. This is the first time a two-dimensional transport data set is reported for demonstrating the multidimensional transport characteristics of nanoparticles. The data shows the importance of density effects, which cannot be fully discerned using one-dimensional, column experiments. Finally, we also demonstrate that the numerical model SEAWAT can be used to predict the density-driven transport characteristics of S-INP in groundwater aquifers.
authors.affiliation: Department of Civil Engineering, Auburn University, Auburn, Alabama 36849, USA.
authors.forename: S R
authors.initials: SR
authors.lastname: Kanel
authors.forename: R R
authors.initials: RR
authors.lastname: Goswami
authors.forename: T P
authors.initials: TP
authors.lastname: Clement
authors.forename: M O
authors.initials: MO
authors.lastname: Barnett
authors.forename: D
authors.initials: D
authors.lastname: Zhao
mesh_terms: D007501:Iron / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D016062:Porosity; D013499:Surface Properties; D014186:Transportation
chemical_list: D007501:Iron