Date of Award

Spring 2021

Document Type

Open Access Dissertation

Department

Chemistry and Biochemistry

First Advisor

Susan D. Richardson

Abstract

Population growth and global climate change has resulted in the degradation of pristine water sources, causing issues like saltwater intrusion, persistent harmful algal blooms, and drought from population growth. Future reliance on alternative sources of drinking water to is expected globally, therefore, nontraditional sources of drinking water are becoming increasingly vital sources of potable water around the world. For example, desalination (typically by reverse osmosis), despite its high energy demands and high cost, is being utilized all over the world to meet drinking water demand. Wastewater reuse, the additional treatment of wastewater to produce drinking water, either directly or indirectly, is also being explored, with the largest indirect potable reuse system in the world producing one hundred million gallons of water a day in California. Traditional drinking water treatment is also being impacted; harmful algal blooms are increasing in both frequency and abundance, putting additional strain on drinking water treatment needs and impacting drinking water quality in ways that are not fully understood.

Desalination, in an effort to maintain and extend the lifetime of filters and membranes, pre-chlorinate intake waters, forming chlorinated brines that are released back into the aquatic environment without additional treatment. Wastewater reuse is required to remove contaminants traditional wastewater treatment does not, resulting in the use of both traditional (UV/H2O2) and novel (UV/NO3−/HCO3−) advanced oxidation processes (AOPs) to remove emerging contaminants (ECs) without forming equally concerning transformation products. Harmful algal blooms and their resulting toxins must be assessed in the environment before steps can be taken toward remediation, but quantitative approaches for individual toxins have previously been unavailable.

Three studies presented here integrate newly developed analytical methods for the assessment of desalination, advanced oxidation, and harmful algal bloom impacted water systems. Pre-chlorination practices in desalination facilities impact both public health and the aquatic environment through the production of toxic disinfection by-products (DBPs). Wastewater reuse via two different AOPs are shown to degrade ECs, but do so incompletely, forming new transformation products that impact toxicity. Toxins specific to Lyngbya wollei, a freshwater algae impacting drinking water sources across the United States, are analyzed by high resolution mass spectrometry that resulted in a new, selective, and sensitive method for the quantification of Lyngbya wollei toxins.

Available for download on Tuesday, August 15, 2023

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