Influence of dissolved oxygen on silver nanoparticle mobility and dissolution in water-saturated quartz sand

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 15; no. 7; pp. 1 - 13
• Main Authors: Mittelman, Anjuliee M., Taghavy, Amir, Wang, Yonggang, Abriola, Linda M., Pennell, Kurt D.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2013; Springer; Springer Nature B.V
• Subjects: Aging; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cross-disciplinary physics: materials science; rheology; Dissolution; Dissolved oxygen; Exact sciences and technology; Inorganic Chemistry; Kinetics; Lasers; Materials Science; Mathematical models; Mobility; Nanocomposites; Nanocrystalline materials; Nanomaterials; Nanoparticles; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanotechnology; Optical Devices; Optics; Oxygen; Photonics; Physical Chemistry; Physics; Quartz; Research Paper; Sand; Silver; Transport; Porous media; Fate and transport; Dissolved oxygen; Dissolution; Silver nanoparticles; pH value; Porous materials; Digital simulation; Theoretical study; pH effect; Quartz; Nanoparticles; Silver; Modelling; Oxidation; Nanostructured materials
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-013-1765-4

The influence of dissolved oxygen (DO) on the transport behavior and dissolution kinetics of silver nanoparticles (nAg) was explored through a combination of experimental and mathematical modeling studies. One-dimensional column experiments were conducted with water-saturated 40–50 mesh Ottawa sand, operated at pH 4 or 7 under three DO conditions (8.9, 2, or <0.2 mg/L). The experimental protocol consisted of a nAg deposition phase, designed to assess nanoparticle mobility as a function of DO level, followed by a dissolution phase, to evaluate the release of Ag + from retained nanoparticles. Experimental observations revealed that the mobility of nAg increased by 15 % when the DO level was reduced from 8.9 to <0.2 mg/L at pH 4, and that, once retained by the quartz sand, the fraction of nAg mass eluted as Ag + decreased from 21.6 to 13.5 to 11.3 % with decreasing oxygen level (8.9, 2, and <0.2 mg/L, respectively). In both batch and column studies, rates of nAg dissolution decreased over time, behavior attributed to aging of the nanoparticle surface due to oxidation. A hybrid Eulerian–Lagrangian nanoparticle transport model was developed and implemented to simulate the mobility of nAg, subject to DO-dependent dissolution kinetics and particle aging. Model simulations accurately captured nAg transport and dissolution as a function of pH and DO level, and demonstrate the importance of considering nanoparticle surface aging to accurately predict Ag + release over time.