Masters Theses

Keywords and Phrases

arsenic sequestration; bacterial metabolism; bioremediation; groundwater remediation; microbiology; nitrate reduction

Abstract

"The highly contaminated subsurface matrix of the Baird and McGuire Superfund site is currently threatening the health and safety of the surrounding environment of Holbrook, MA. Contaminants of significant concern due to high concentration are inorganic arsenite and petroleum hydrocarbons, such as naphthalene. Parsons Corporation and the Massachusetts Department of Environmental Protection have implemented a bioremediation pilot to attempt to degrade the hydrocarbons and arsenic with the application of nitrate. The nitrate would act as an electron acceptor for biodegradation of the hydrocarbon contaminants, produce nitrite that would oxidize reduced iron, and iron oxides would sequester arsenic. Preliminary data showed that nitrate was utilized quickly compared to lab rates and was not distributed to the entire contaminant plume. Additionally, arsenic that was sequestered began to be released into the aqueous phase again over time. The purpose of this study was to investigate nitrate utilizing metabolisms to determine how nitrate is being used by the microorganisms in the subsurface as well as determine what treatments create iron minerals that are capable of long-term arsenic sequestration. It was found that the addition of a labile carbon/electron source such as lactate can facilitate rapid denitrification and when the only source of carbon/electrons are the hydrocarbon contaminants, many metabolisms take place. The iron oxide mineral goethite is primarily produced under nitrate reducing conditions with an added carbon/electron source and is capable of arsenic sequestration. When an abundance of iron is present under nitrate reducing conditions, arsenic will be sequestered and will not be released over a six-month period"--Abstract, p. iv

Advisor(s)

Mormile, Melanie R.

Committee Member(s)

Ulrich, Glenn
Borrok, David M.
Niyogi, Dev

Department(s)

Biological Sciences

Degree Name

M.S. in Applied and Environmental Biology

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2023

Pagination

xii, 67 pages

Note about bibliography

Includes bibliographical references (pages 64-66)

Rights

© 2023 Cassie Marie Roberts, All Rights Reserved

Document Type

Thesis - Open Access

File Type

text

Language

English

Thesis Number

T 12258

Electronic OCLC #

1426306236

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Microbiology Commons

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