Date of Award

8-2016

Document Type

Thesis

Degree Name

Master of Science (MS)

Legacy Department

Environmental Engineering

Committee Member

Dr. Nicole Martinez, Committee Chair

Committee Member

Dr. Brian Powell

Committee Member

Dr. Nishanth Tharayil

Abstract

The work herein investigates the potentially competitive uptake and translocation of plutonium (Pu) and iron (Fe) in corn (Zea mays) to gain insight into the Pu uptake pathway. Plutonium has no known biological function in plants yet it has many chemical properties similar to Fe (an essential nutrient) implying that Pu may share the Fe uptake pathway. A series of experiments was conducted in which two hydroponically grown corn species (one healthy and one deficient in the transporter protein for Fe) were exposed to varying ratios of complexed Pu and Fe. Results suggest increased presence of Fe inhibits Pu translocation into the shoots of the corn plant. For example, increasing the Fe concentration in hydroponic solution from 1 ppb FeCl3 to 10 ppb FeCl3 resulted in Pu concentrations to decrease from a 7.57 (+/- 0.00 ) mg g-1 median shoot Pu concentration to 2.7300 (+/- 1.203) mg g-1 in a healthy strain of corn. Additionally, comparison of citrate and DFOB ligand influence on Pu uptake and translocation into corn plants determine Pu complexed with DFOB remained in the roots of the plant, while translocation of Pu into the shoots of the plant was more prevalent with the Pu-citrate complex.

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