Publication Date

2018

Document Type

Dissertation

Committee Members

Abinash Agrawal (Committee Chair), Willie Harper, Jr. (Committee Member), Steven Higgins (Committee Member), Marc Mills (Committee Member), Ioana Sizemore (Committee Member), Doyle Watts (Committee Member)

Degree Name

Doctor of Philosophy (PhD)

Abstract

Sites contaminated with chlorinated hydrocarbons are frequent and widespread, and with the rising use of insensitive high explosive (IHE) compounds, more widespread contamination is inevitable. In the cases of both classes of organic contaminants, natural attenuation is a critical component of our understanding of the environmental fate of these compounds. This dissertation is intended to expand the knowledge of potential abiotic natural attenuation mechanisms and, in the case of the study of chlorinated hydrocarbons, to examine degradation under variable pH conditions in the hopes of helping to develop minimally invasive remediation techniques. The results indicated that precipitated hydrolyzed Fe(II) species are more reactive toward chlorinated hydrocarbons than precipitated magnetite particles alone. The combination of precipitated magnetite with Fe(II) species at high pH were found to have a slightly slower reaction than Fe(II) species but produced more reduced byproducts than either Fe(II) species or magnetite particles alone. Until this study, reduction of 2,4-dinitroanisole (DNAN) had not been studied with naturally occurring iron oxide minerals. Fe(II) added to hydrous ferric oxide and goethite at neutral to basic pH facilitated nitroreduction of insensitive explosive component, 2,4-dinitroanisole (DNAN) to various nitroaniline byproducts. Magnetite was found to be a stronger reductant for DNAN, degrading it with and without Fe(II) amendments at pH 6 to 10. The study with magnetite and DNAN demonstrated that structural Fe(II) was more reactive than adsorbed Fe(II).

Page Count

394

Department or Program

Department of Earth and Environmental Sciences

Year Degree Awarded

2018


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