title: Transport and deposition of stabilized engineered silver nanoparticles in water saturated loamy sand and silty loam.
abstract: It is considered inevitable that the increasing production and application of engineered nanoparticles will lead to their release into the environment. However, the behavior of these materials under environmentally relevant conditions is still only poorly understood. In this study the transport and deposition behavior of engineered surfactant stabilized silver nanoparticles (AgNPs) in water saturated porous media was investigated in transport experiments with glass beads as reference porous medium and in two natural soils under various hydrodynamic and hydrochemical conditions. The transport and retention processes of AgNPs in the porous media were elucidated by inverse modeling and possible particle size changes occurring during the transport through the soil matrix were analyzed with flow field-flow fractionation (FlFFF). A high mobility of AgNPs was observed in loamy sand under low ionic strength (IS) conditions and at high flow rates. The transport was inhibited at low flow rates, at higher IS, in the presence of divalent cations and in a more complex, fine-grained silty loam. The slight decrease of the mean particle size of the AgNPs in almost all experiments indicates size selective filtration processes and enables the exclusion of homoaggregation processes.
authors.affiliation: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, 52064 Aachen, Germany. Electronic address: braun@lih.rwth-aachen.de.
authors.forename: Anika
authors.initials: A
authors.lastname: Braun
authors.affiliation: Institute Agrosphere, IBG-3, Institute of Bio- and Geosciences, Forschungszentrum Juelich GmbH, 52425 Juelich, Germany.
authors.forename: Erwin
authors.initials: E
authors.lastname: Klumpp
authors.affiliation: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, 52064 Aachen, Germany.
authors.forename: Rafig
authors.initials: R
authors.lastname: Azzam
authors.affiliation: RWTH Aachen University, Department of Engineering Geology and Hydrogeology, Lochnerstr. 4-20, 52064 Aachen, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Neukum
mesh_terms: D053768:Metal Nanoparticles / Q000032:analysis*; D008956:Models, Chemical; D009994:Osmolar Concentration; D010316:Particle Size; D016062:Porosity; D012822:Silicon Dioxide; D012834:Silver / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver; D012822:Silicon Dioxide
keywords: Engineered nanoparticle; Soil; Transport and retention; Transport modeling