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As part of an Environmental Protection Agency grant to reduce the trihalomethane concentration in the Melbourne, Florida drinking water, a granular activated carbon (GAC) plant was operated for approximately 1 year. Four GAC pilot plant systems were operated in parallel each treating a different influent. Raw water, coagulated, settled and filtered water, filtered water with ozone pretreatment, and filtered water with chlorine dioxide pretreatment were pumped through the individual systems. Influent and effluent concentrations of various pollutants were monitored regularly throughout the study. The raw water GAC system showed rapid breakthrough for color, total organic carbon (TOC) and trihalomethanes (THM's). It was concluded that GAC treatment of raw water was inefficient and would require enormous quantities of GAC. The three coagulated, settled, and filtered water systems showed little variation in the removal of color, TOC and THMFP. For this reason, ozone and chlorine dioxide would not be useful in increasing the removal of pollutants from the Melbourne water. The most attractive use of GAC was evident with the coagulated, settled, and filtered water. At no time during the study did the effluent concentrations approach the influent concentrations of the three major pollutants. In addition, the predicted capacity of the GAC based on batch studies was exceeded significantly. It appears biological growth was present within the activated carbon and is aiding the GAC with pollutant removal. With biological activation, carbon usage rates could be significantly reduced, thus making the GAC alternative economically feasible.

In this thesis, the results of oxidation and decarburization experiments with pure iron-carbon alloys over the temperature range 800 - 950ºc, and in atmospheres of varying carbon monoxide - carbon dioxide ratio are reported. Most of the experimental work is concerned with a 1.065 weight percent carbon alloy at temperatures where austenite is the stable phase. Complex kinetic behaviour was observed for this alloy in the range 10 - 100 volume percent carbon dioxide. An analysis is given which in turn associates the kinetics with a pure diffusion controlled decarburization model and a pure surface controlled decarburization model. The latter best represents the interaction of the decarburization mechanism with the scaling process on Y - iron. Metallographic evidence is provided where possible in support of the results of the afore-mentioned analysis. Mathematical relations are introduced which attempt to describe qualitatively the kinetics of the carbon alloys in all the atmospheres employed. A statement is made as to the applicability of the model to carbon steels in general at temperatures where austenite is the stable phase and where the atmospheres employed are of various carbon monoxide - carbon dioxide ratio. / Thesis / Master of Science (MS)

Single-walled carbon nanotubes (SWNTs), since their first discovery in early 1990s, have drawn enormous research attention owing to their extraordinary properties. These excellent optical, electrical, thermal and mechanical properties have enabled SWNTs to make profound impacts in the field of nanotechnology, which includes nanoscale nanoelectronics, chemo-/biosensors, photovoltaics, drug delivery, and advanced nanocomposite materials. However, the as-produced SWNT samples contain a mixture of metallic and semiconducting SWNTs, amorphous carbon, and metal catalyst particles. Also, due to π-π stacking and van der Waals forces, pristine SWNTs tend to form bundles, making them insoluble in most of organic solvents. The poor processibility and purity hinder the direct use of as-produced SWNTs as the material for fabrication of SWNT-based devices. Therefore, the post-synthesis purification is highly required. Conjugated polymers have proven to be efficient SWNT dispersants, but after solution processing, conjugated polymers adhered to the sidewall of SWNTs can not be easily removed and thus negatively affect the performance of the resulting SWNT-based electronic devices. Therefore, polymers that can dissociate from the surface of SWNTs after solution processing is highly desirable. Apart from the introduction to several other efficient purification methods of SWNTs, Chapter 1 also gives a brief review on reversible functionalization of SWNTs by polymers. The work reported in the literature categorized by the different external stimuli used to reverse the polymer-SWNT association. Chapter 2 describes the design and synthesis of a vinylogous tetrathiafulvalene (TTFV)-based conjugated polymer, which is responsive to pH changes and thus realized reversible functionalization of SWNTs. Chapter 3 describes the design and synthesis of dithiafulvenyl-grafted phenylene ethynylene polymers, which can reversibly interact with SWNTs by changing solvents. Chapter 4 describes the design and synthesis of dithiafulvene (DTF)-based electron-rich conjugated polymers, which can selectively bind with semiconducting SWNTs. In addition, Chapter 5 describes the use of SEC to achieve high-resolution separation, and isolation of surfactant-free metallic and semiconducting SWNTs. This allowed us to study the competition behavior when different ratios of metallic and semiconducting nanotubes are used as the starting material for polymer dispersions. Finally, Chapter 6 describes a side project that involves covalent functionalization of GO using Piers-Rubinsztajn reaction. The functionalized GO is loaded into silicone elastomer to reduce the air permeability and enhance the mechanical strength of the resulting silicone elastomer. / Thesis / Doctor of Philosophy (PhD)