Date of Graduation

5-2016

Document Type

Thesis

Degree Name

Bachelor of Science in Civil Engineering

Degree Level

Undergraduate

Department

Civil Engineering

Advisor/Mentor

Zhang, Wen

Committee Member/Reader

Coffman, Richard

Committee Member/Second Reader

Hall, Kevin

Abstract

Reclaiming treated wastewater for potable water use may be necessary to supplement drinking water sources in water scarce regions. However, Snyder et al. (2003) indicates that endocrine disrupting compounds (EDCs) are commonly found in wastewater effluents and natural waters around the world. These compounds with endocrine disrupting potential are typically found in personal care products, pharmaceuticals, and pesticides. Furthermore, according to Lemanik et al. (2007), typical wastewater treatment plants are not designed to remove EDCs.

For the purpose of water reuse, benchmarking wastewater treatment for endocrine disrupting compounds (EDCs) is necessary. The cytotoxicities of five EDCs (namely, amoxicillin, acetaminophen, triclosan, estrone, and atrazine) were assessed using the Microtox assay. The in vitro assay was utilized to correlate light emission of a naturally luminescent marine bacterium, Vibrio fischeri, to the relative cytotoxicities of the selected EDCs. The cytotoxicities of the five EDCs were evaluated in a sodium chloride buffer, within wastewater after primary treatment in a municipal wastewater plant, and within wastewater during and after secondary treatment in a laboratory. A comparison between toxicities of well-studied compounds and EDCs was conducted to gain an understanding of the noxious potential of the aforementioned compounds.

From the greatest to least toxic compound to V. fischeri, the relative toxicity of the studied EDCs falls in the order of triclosan, estrone, atrazine, amoxicillin, and acetaminophen. An Empirical Toxicity Scale approved by the European Community Commission and affiliated with Persoone et al. (1993) was utilized to assign a toxicity classification to the studied compounds. Based on the scale, triclosan and atrazine classify as toxic, and amoxicillin, acetaminophen, and atrazine categorize as weakly toxic. However, EDCs did not have a significant toxic effect to V. fischeri at concentrations typically found in wastewater effluents.

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