title: Mobility of nanosized cerium dioxide and polymeric capsules in quartz and loamy sands saturated with model and natural groundwaters.
abstract: The environmental and health risks posed by emerging engineered nanoparticles (ENPs) released into aquatic environments are largely dependent on their aggregation, transport, and deposition behavior. Herein, laboratory-scale columns were used to examine the mobility of polyacrylic acid (PAA)-coated cerium dioxide nanoparticles (nCeO2) and an analogous nanosized polymeric capsule (nCAP) in water saturated quartz sand or loamy sand. The influence of solution ionic strength (IS) and cation type (Na(+), Ca(2+), or Mg(2+)) on the transport potential of these ENPs was examined in both granular matrices and results were also compared to measurements obtained using a natural groundwater. ENP suspensions were characterized using dynamic light scattering and nanoparticle tracking analysis to establish aggregate size, and laser Doppler electrophoresis to determine ENP electrophoretic mobility. Regardless of IS, virtually all nCeO2 particles suspended in NaNO3 eluted from the quartz sand-packed columns. In contrast, heightened nCeO2 and nCAP particle retention and dynamic (time-dependent) transport behavior was observed with increasing concentrations of the divalent salts and in the presence of natural groundwater. Enhanced particle retention was also observed in loamy sand in comparison to the quartz sand, emphasizing the need to consider the nature of the aqueous matrix and granular medium in evaluating contamination risks associated with the release of ENPs in natural and engineered aquatic environments.
authors.affiliation: Department of Chemical Engineering, McGill University, 3610 University St., Montreal, Quebec, Canada H3A 2B2.
authors.forename: Adamo Riccardo
authors.initials: AR
authors.lastname: Petosa
authors.forename: Carolin
authors.initials: C
authors.lastname: Ohl
authors.forename: Faraz
authors.initials: F
authors.lastname: Rajput
authors.forename: Nathalie
authors.initials: N
authors.lastname: Tufenkji
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D002563:Cerium / Q000737:chemistry*; D060587:Groundwater / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D011791:Quartz / Q000737:chemistry*
chemical_list: D000180:Acrylic Resins; D011108:Polymers; D011791:Quartz; D002563:Cerium; C006903:carbopol 940; C030583:ceric oxide
keywords: Cerium dioxide; Loamy sand; Nanoparticle; Nanoparticle tracking analysis; Polyacrylic acid; Transport