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Date Permissions Signed


Date of Award


Document Type

Masters Thesis

Degree Name

Master of Science (MS)


Environmental Sciences

First Advisor

Sofield, Ruth M.

Second Advisor

Matthews, Robin A., 1952-

Third Advisor

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

OCLC Number


Subject – LCSH

Freshwater algae--Effect of heavy metals on; Silver ions--Absorption and adsorption




masters theses




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