Audrey McGowin, Ph.D. (Committee Chair); David Dolson, Ph.D. (Committee Member); Eric Fossum, Ph.D. (Committee Member)
Master of Science (MS)
Previous investigations into the presence of benzotriazole (BTZ) and corresponding analogs done in early 2019 found elevated levels near the Wilmington Air Park in Wilmington, Ohio. The analogs detected were 4-methyl-1H-benzotriazole and 5-methyl-1H-benzotriazole: known together as tolytriazole (TTZ). BTZ and TTZ are emerging environmental contaminants of concern that are often found in aircraft de-icing solutions, anti-icing solutions and detergents. The Wilmington Air Park has two facilities used to pre-treat runoff water before its subsequent release into surrounding streams. Three sites were chosen: Lytle Creek, Indian Run, and Cowan Creek. For the 2019 and 2019/2020 investigative projects, Cowan Creek was designated the control site. Eight sample days were completed from November 2019 to March 2020. The method used in this 2019/2020 sample season utilized the solid-phase extraction (SPE) method and maintained analysis by liquid chromatography-mass spectroscopy (LC-MS). Ultimately, BTZ was below limits of detection at either the Cowan Creek or Indian Run site. BTZ was detected on seven of the eight sample days at Lytle Creek. TTZ was detected all sample days at both the Lytle Creek and Indian Run sites. Recovery corrected BTZ concentrations (internal standard was 5,6-dimethylbenzotriazole) ranged from 0.148 to 3.47 µg/L at the Lytle Creek site. Recovery corrected TTZ concentration ranges were 0.725-12.0 µg/L and 0.214-5.66 µg/L for Lytle Creek and Indian Run, respectively. This would seem to indicate that the treatment facilities are not 100% effective, and that air traffic may have increased. The sample day with the highest TTZ concentrations was the coldest. Correspondingly, the lowest concentrations were days with the highest ambient temperature. Observed BTZ concentrations were within reported literature ranges, while TTZ concentrations were significantly higher than others reported. The concentrations detected would be considered below levels of acute toxicity to aquatic species, chronic toxic effects cannot be ruled out.
Department or Program
Department of Chemistry
Year Degree Awarded
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