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The Transport and Fate of Metal and Metal Oxides Nanoparticles under Different Environmental Conditions

Li, Zhen
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427963167

Abstract Details

2015, PhD, University of Cincinnati, Engineering and Applied Science: Environmental Engineering.
Engineered Nanoparticles (NPs) have been widely used in various industrial processes and consumer products. While there seems to be unlimited potential that nanotechnology would improve the quality of our lives, it is inevitable that these manufactured materials will find their way to enter the environment. This study systematically studied the transport, retention and deposition of several industrially important metal and metal oxides NPs (CeO2, TiO2, ZnO and Ag) under different environmental conditions in the aquatic systems. The stability, transport and deposition of engineered CeO2 nanoparticles through water-saturated column packed with sand were studied by monitoring effluent CeO2 concentration. The influence of solution chemistry such as ionic strength (1–10 mM) and pH (3–9) on the mobility and deposition of CeO2 nanoparticles was investigated by using a three-phase (deposition-rinse-reentrainment) procedure in packed bed columns. The results show that water chemistry governs the transport and deposition of CeO2 nanoparticles. A mathematical model was developed based on advection-dispersion-adsorption equations and it successfully predicts the transport, deposition and re-entrainment of CeO2 nanoparticles through a packed bed. There is strong agreement between the deposition rate coefficients calculated from experimental data and predicted by the model. This study also studied the role of natural organic matter (NOM) in the transport and fate of NPs in the aquatic environments. Unlike other studies which used synthesized or standardized NOM samples, this study used NOM that was obtained from OhiO River, which has more practical relevance. The influence of this NOM on the surface charge, transport and retention of Ceria NPs was investigated in packed columns. Results indicated that the properties of Ohio River NOMs (OR-NOMs) differ from Suwannee River Humic Acid (SRHA), which is commonly used as standard NOM in similar researches. OR-NOMs showed a distinct effect in stabilizing and mobilizing CeO2, and the summer NOM had a higher stabilizing effect than winter NOM. The stabilizing effect is attributed to both electrostatic effect and steric effect. This study also characterized, experimentally and theoretically, the transport and retention of engineered NPs through slow sand filters at drinking water treatment plants (DWTPs) under realistic conditions. The transport of four commonly used NPs (ZnO, CeO2, TiO2, and Ag, with bare surfaces and coated with capping agents) through filter beds filled with three difference sand surfaces were investigated. The results have shown that capping agents have a determinant importance in the colloidal stability and transport of NPs through the different filter media. The effort of the biofilm was less significant. The data was used to build a mathematical model which was used to simulate the performance of a scale-up slow sand filter and the effects on filtration cycle of traditional sand filtration system used in DWTPs. Finally, the study took a further step to examined and compared industrially coated and lab-coated NPs in the biofilm coated porous media and confirmed that The role of steric repulsion between electrostatically stabilized NPs and biofilm is a prevalent force against NPs retention in saturated porous media.
George Sorial, Ph.D. (Committee Chair)
Ashraf Aly Hassan, Ph.D. (Committee Member)
E Sahle-Demessie, Ph.D. (Committee Member)
Margaret Kupferle, Ph.D. P.E. (Committee Member)
Makram Suidan, Ph.D. (Committee Member)
175 p.
Environmental Engineering
Nanoparticles; Fate and transport; environmental; aquatic; polymer coating; biofilm

Recommended Citations

Citations

  • Li, Z. (2015). The Transport and Fate of Metal and Metal Oxides Nanoparticles under Different Environmental Conditions [Doctoral dissertation, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427963167

    APA Style (7th edition)

  • Li, Zhen. The Transport and Fate of Metal and Metal Oxides Nanoparticles under Different Environmental Conditions. 2015. University of Cincinnati, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427963167.

    MLA Style (8th edition)

  • Li, Zhen. "The Transport and Fate of Metal and Metal Oxides Nanoparticles under Different Environmental Conditions." Doctoral dissertation, University of Cincinnati, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1427963167

    Chicago Manual of Style (17th edition)

ucin1427963167
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© 2015, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.