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Date Permissions Signed
Date of Award
Master of Science (MS)
Sofield, Ruth M.
Matthews, Robin A., 1952-
Patrick, David L.
Silver nanoparticle (AgNP) containing products are abundant in consumer goods. If trends continue, AgNP levels will continue to rise as innovative applications continue to be realized. These nanoparticles (NPs) can enter the environment as their uses can transport them to natural waters (e.g., washing socks containing AgNPs). Research on the behavior of AgNPs and Ag+ in artificial fresh water is presented in this thesis. Specifically, their sorptive properties between fresh water and freshwater algae, Pseudokirchneriella subcapitata (Korshikov) Hindák, as a function of hardness, humic acid (HA) content, and silver type were investigated. The experimental design was modeled after a 23 factorial analysis in which each factor is varied at two levels: (1) no added HA and with HA, (2), Ag type [AgNP versus Ag+], and (3) low hardness and high hardness. The Freundlich Isotherm method was used to determine the KF partitioning constants at the varying conditions. The effects of each factor on partitioning constants were evaluated. A normal probability plot was used to determine which factors had the greatest effect. Results were that the greatest effects were caused by hardness and the interaction between hardness and HA. An increase in hardness caused a decrease in Ag sorption by an average log KF of 0.46475, whereas the interaction between hardness and HA caused an increase in Ag sorption by an average log KF of 0.40375. The other two main effects (Ag type and HA content) also had an effect on sorption. However, these main effects were not as great as that observed with hardness.
Western Washington University
Copying of this thesis in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this thesis for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Ferguson, Matthew D., "The influence of humic acid and water hardness on the partitioning of silver ions and nanoparticles between fresh water and freshwater algae" (2011). WWU Masters Thesis Collection. 182.