Audrey McGowin, Ph.D. (Advisor); Steven Higgins, Ph.D. (Committee Member); Eric Fossum, Ph.D. (Committee Member)
Master of Science (MS)
Benzotriazoles are a class of contaminant of emerging concern which are commonly used as anticorrosive agents in aircraft deicer and anti-icing fluids (ADAFs). The analogues 1H-benzotriazole (BTZ), 4-methyl-1H-benzotrizole (4m-BTZ), and 5-methyl-1H-benzotriazole (5m-BTZ) are commonly found in environmental occurrence together. The two methylated isomers, collectively known as tolytriazole (TTZ), have different toxicity and stability. These contaminants are highly water soluble and resistant to biodegradation, making them persistent through water treatment. Benzotriazoles have been detected worldwide; this investigation focuses on monitoring three sites near a small airpark in Wilmington, Ohio. Two sites that receive runoff from the airpark, Lytle Creek and Indian Run, have been under investigation for decades due to documented poor water quality issues. This investigation adds to data from the two previous years documenting an increase in BTZ compounds that corresponds to an increase in activity at the airpark by an online retailer. Solid Phase Extraction (SPE) was used to isolate benzotriazoles from surface water samples. Liquid Chromatography/Mass Spectrometry (LC/MS) was used for separation and detection of analytes. Each consecutive monitoring season detected more BTZ and TTZ on average than previous seasons. The 2021 season detected TTZ from 0.346-1.785 µg/L at Indian Run. Lytle Creek yielded BTZ from 0.051-0.158 µg/L and TTZ from 1.700-51.87 µg/L. Other occurrences have detected BTZ compounds associated with airpark runoff ranging from ng/L to mg/L. Gas Chromatography/Mass Spectrometry (GC/MS) was employed to separate the two TTZ isomers that could not be separated by LC/MS. This method revealed a ratio of 41.29% 4m-BTZ and 58.71% 5m-BTZ in selected water samples, a ratio which is similar to findings in a Wisconsin study. Based on the ratios of each isomer, hazard quotients assessed most samples analyzed as low environmental risk with a few days presenting medium to high environmental risk. Sediment samples were also examined for presence of benzotriazoles, but the results were inconclusive.
Department or Program
Department of Chemistry
Year Degree Awarded
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