Thesis (Ph.D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Jae-Hong Kim; Committee Member: Joseph hughes; Committee Member: Michael Bergin; Committee Member: Seung Soon Jang; Committee Member: Vernon Snoeyink.

Environmental impact of fullerenes such as C60 and carbon nanotubes is of great concern due to the projection for widespread application and mass production in near future. Understanding their fate in the aqueous phase is prerequisite for accurate assessment of their ecotoxicological and human health effects upon unintended release to environment. This research addresses outstanding questions related to the behavior of fullerenes in natural and engineered water environments. Specifically, this research focuses on investigating: 1) the stability of fullerenes in the natural water, 2) interaction between fullerenes and natural organic matter (NOM), and 3) treatability of water stable fullerenes by conventional water treatment process. The experimental results suggested that NOM readily interacts with fullerenes leading to the formation of water stable fullerene suspensions. The adsorptive interaction between NOM and fullerenes was largely affected by NOM characteristics as well as water quality parameters. The fate of fullerenes in water environments was also greatly influenced by the types of fullerenes (e.g., single walled carbon nanotubes, multi-walled carbon nanotubes, and C60) and the pathway they are introduced into the aqueous phase. These water stable fullerene suspensions were found to be relatively well removed by conventional water treatment processes while the presence of NOM could negatively impact the removal efficiency. The outcomes of this study collectively imply that the dispersion of fullerenes in the natural water can occur beyond the level predicted only based on their extreme hydrophobicity and NOM plays a critical role on the fate of fullerenes both in natural and engineered water environments.

The development of analytical methods for emerging contaminants creates many unique challenges for analytical chemists. By their nature, emerging contaminants have inherent data gaps related to their environmental occurrence, fate, and impact. This dissertation is a compilation of three studies related to method development for the structural identification of emerging contaminants, the detection and quantification of chemicals used in unprecedented quantities and applications, and the extraction of compounds from complex matrices where the solvent-solute-matrix interactions are not completely understood. The three studies present analytical methods developed for emerging contaminants in complex matrices, including: fluorochemical surfactants in aqueous film-forming foams, oil dispersant surfactants in seawater, and fullerene nanomaterials in carbonaceous solids. Aqueous film-forming foams, used in military and commercial firefighting, represent environmentally-relevant commercial mixtures that contain a variety of fluorochemical surfactants. Combining the surfactant-selective ionization of fast atom bombardment mass spectrometry with high resolution mass spectrometry, chemical formulas for 11 different fluorochemical classes were identified. Then AFFF-related patents were used to determine the structures. Of the eleven classes of fluorochemicals, ten have little, if any, data on their environmental occurrence, fate, and potential impacts in the peer-reviewed literature. In addition, nine of the identified classes had either cationic or zwitterionic functionalities and are likely to have different transport properties compared to the well-studied anionic fluorochemicals, such as perfluorooctanoate. After the Deepwater Horizon oil spill in the summer of 2010, one of the emergency response methods for the mitigation of the oil's environmental impact was the use of unprecedented amounts of oil dispersant to break down the oil slick and encourage biodegradation. This event illustrated the need for rapid analytical method development in order to respond to the potential environmental disaster in a timely manner. Using large volume injection liquid chromatography with tandem mass spectrometry, an analytical method was developed for the trace analysis of the multiple dispersant surfactant classes and the potential degradation products of the primary surfactant. Limits of detection ranged from 49 ��� 3,000 ng/L. The method provided excellent recovery (86 ��� 119%) and precision (10 ��� 23% RSD), while also accommodating for the high salinity of seawater samples and analyte contamination. Despite the fact that fullerene nanomaterials have been studied for almost three decades, research is still being conducted to fully understand the environmental properties of these materials. Previous studies to extract fullerenes from environmental matrices have resulted in low efficiency, high variability, or the extraction efficiencies have gone unreported. Extraction by ultrasonication with toluene and 1-methylnaphthalene increased the recovery 5-fold of a spiked, isotopically-labeled C������ surrogate from carbon lampblack as compared to that of the conventional approach of extracting with 100% toluene. The study revealed the importance of evaluating experimental variables such as extraction solvent composition and volume, and sample mass, as they have a significant impact on the quantitative extraction of fullerenes from environmental matrices. / Graduation date: 2013 / Access restricted to the OSU Community at author's request from Aug. 15, 2012 - Aug. 15, 2013