Date of Award:

8-2022

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Civil and Environmental Engineering

Committee Chair(s)

Joan E. McLean

Committee

Joan E. McLean

Committee

Astrid R. Jacobson

Committee

David W. Britt

Committee

David K. Stevens

Abstract

Nanoparticles (NPs) are particles less than 100 nm (~4 millionths of an inch) in a direction. NPs, due to their small size, are used in a variety of products, such as silver (Ag) NPs as an antimicrobial in clothes. Copper Oxide (CuO) NPs are used in electronics as semiconductors and other fields as antimicrobials and purposefully or accidentally end up in the environment. Copper (Cu) is a necessary nutrient for plants, but at higher amounts is toxic to plants and beneficial soil microbes.

In order to understand how the CuO NPs interacts with plants, wheat seedlings were grown in sand for 10 days. The sand was watered with water extracted from three soils differing in properties relevant to CuO NP dissolution. The SPEs were either sterilized, to provide information on the wheat releases (exudates) into the sand as it grows, or contained native microbes, so that the wheat with microbes could mimic a natural environment. The sand was amended with a low and high dose of CuO NPs to provide two different environments for the wheat to react in.

The higher dose of CuO caused the wheat to release greater amounts of exudates. In the presence of microbes, the amounts of exudates drastically decreased, yet the amount of Cu complexed did not drastically change; instead, soil components such as fulvic acid complexed with the Cu. The amount of Cu associated with the roots depended on the amount of NPs added and resulted in root mass with wheat that had less organic matter in the SPEs, but the wheat, regardless of the conditions it was grown in, was able to regulate the amount of Cu taken into the shoots.

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