The Impacts and In-Depth Study of the Environmental Contaminant, Perfluorooctane Sulfonic Acid, and Its Interactions with Water

Perfluorooctanesulfonic acid (PFOS), similar to perfluorooctanoic acid (PFOA), is a synthetic chemical that has been classified as a persistent organic pollutant (POP) by the Stockholm Convention since 2009. Due to the wide previous usage, high stability, high bio-accumulative, and low degradative properties is the reason that PFOS has been found in several compartments of the environment including ocean water, ground water, air, and sediments. Due to the strong interactions generated by the sulfonic acid end, this compound has a tendency to stay in the environment for long periods of time and has proved to be difficult in the removal from water. This is alarming due to the persistent bioaccumulation of PFOS in the environment leading to further bioaccumulation into animals and humans. This thesis is composed of two projects revolving around PFOS. The first project involves an environmental contaminant survey done in Putian, China. A total of 57 locations were tested that consisted of both, seawater and ground water. In this project, several environmental contaminants, with the inclusion of PFOS, were tested in order to create a baseline documentation for the Putian region in southern China. The main instrumentation used for the detection of PFOS and PFOA was the Solid Phase Extraction (SPE) Enrichment with Ultra High-Performance Liquid Chromatography-Tandem Mass Spectrometry. The second project focuses on the further study of PFOS by studying a smaller and similar prototype molecule, fluorosulfonic acid. Flourosulfonic acid and its complex hydrates are quantum chemically studied theoretically and experimentally to understand the natural behavior of the first solvation shell of fluorosulfonic acid in the environment. The experimental portion of this research is done by using a Chirped-Pulse Fourier Transform microwave spectrometer for the monomer and a cavity-based Fourier Transform microwave spectrometer for the complex hydrates. The computational results are carried out through the cluster computers at the Texas Advanced Computer Center (TACC) located in Austin, Texas. The methods used for the theoretical portion include Density Functional Theory (DFT), second order Møller-Plesset Perturbation Theory (MP2), and the Coupled-Cluster Single Double Triple CCSD(T) Theory with the aug-cc-pVTZ basis set. The completion of this research project will give strong, detailed, and accurate information on the core of the problem for perfluorooctanesulfonic acid (PFOS) to help the future removal of this environmental contaminant