Man Zhang (Minnesota) co-authored a paper entitled, "Transport of stabilized iron nanoparticles in porous media: Effects of surface and solution chemistry and role of adsorption." The paper is published in the Journal of Hazardous Materials' Special Issue for Environmental Nanotechnology in Volume 322, Part A, pages 284-291 in January 2017.
The paper discusses the results of a study to investigate the effects of iron oxide and aluminum oxide on retention and transport of carboxymethyl cellulose (CMC) stabilized zero-valent iron (ZVI) (CMC-ZVI) nanoparticles, and evaluate the role of particle adsorption by means of a modified transport modeling approach. The effects of particle concentrations, natural organic matter, and ionic strength on the transport behavior of stabilized ZVI nanoparticles were also examined. These experimental results and modeling approach can facilitate our understanding of fate and transport of stabilized ZVI nanoparticles under various geochemical conditions.
AbstractCarboxymethyl cellulose (CMC) stabilized zero-valent iron (ZVI) (CMC-ZVI) nanoparticles have been extensively tested for remediation of soil and groundwater. This study investigated effects of iron oxide and aluminum oxide on retention and transport of CMC-ZVI nanoparticles, which have a mean hydrodynamic diameter of 155nm. Column breakthrough experiments showed that the metal oxides coatings on quartz sand greatly enhanced particle retention. A mechanistically sounder transport model was proposed by incorporating a Langmuir-type adsorption rate law into the classic convection–dispersion equation with the adsorption parameters derived from independent experiments. The model allows for a quantitative evaluation of the role of adsorption. While filtration is the primary mechanism for particle retention at lower pore velocities, adsorption becomes more significant at elevated velocities. The presence of 40–80 mg-C L−1 of natural organic matter and high ionic strength (up to 200 mM CaCl2) had negligible effect on the breakthrough profiles of the nanoparticles. Starch, a neutral polysugar stabilizer, was also tested as a stabilizer. Starch-stabilized ZVI nanoparticles, with a mean hydrodynamic diameter of 303 nm, displayed a higher particle retention than CMC-ZVI. The information and modeling approach can facilitate our understanding of fate and transport of stabilized ZVI nanoparticles under various geochemical conditions.
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To learn more about Man see her profile at: https://www.linkedin.com/in/man-zhang-6799232b