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The focus of this thesis is the bioremediation of oil impacted sites. Chapter 3 considered “Oil Lakes” in Kuwait, a consequence of the First Gulf War, which pose a considerable human and environmental hazard.  The data revealed that across even a small “Oil Lake”, the hydrocarbon concentration varied significantly and that hydrocarbon concentration was the most important descriptor for determining the rate of remediation.  Effective and sustainable bioremediation strategy must be led by the focused use of underpinning empirical data and its application in a predictive capacity. Chapter 4 considered a similar integrated approach to assess the bioremediation potential of historically contaminated soils from Kuwait.  The analyses reveal that an optimised combination of chemical and biological characterisation were necessary to monitor processes involved in remediation of heavily weathered oil contaminated soils.  A predictive equation derived from empirical chemical and biological data could enhance certainty in the adoption of remedial strategies. Chapter 5 focussed on the toxicity of fractionated crude oils undergoing remediation. Chapter 6 compared a full scale trial of two remediation strategies done on the same site contaminated with bunker-fuel.  This trial reveals the benefit of developing risk and hazard-based approaches in defining endpoint bioremediation of heavy hydrocarbons when engineered biopile or window are proposed as treatment option. Bioremediation, to be effectively applied requires a considerably intense monitoring regime.  For freshly contaminated soils, there is sound justification for applying a predictive capacity but as the samples age, this becomes less certain.  New technologies are evolving which when properly applied and interpreted in the correct context may enhance our ability to sustainably manage hydrocarbon bioremediation.

Information on the density of hydrocarbons at high pressures and temperatures is of great importance in many fields, such as the study of ultra-deep reservoirs up to ~240 MPa and 250°C. However, density data at such high pressures and temperatures are often not available in the literature. In this study, experimental densities are reported for n-pentane, n-octane, 2,2,4-trimethylpentane, cyclooctane, n-decane, and toluene to ~280 MPa and ~250°C. These experimental densities are in good agreement with available literature data, although the literature data for many of these fluids do not extend to the pressures and temperatures utilized in this study.

Thesis advisor: Lawrence T. Scott / Thermal cyclodehydrogenation is the key step in the total synthesis of fullerene C60 and represents an important family of carbon-carbon bond-forming reactions. My research focuses on understanding the mechanism of C-C bond formation in the high temperature cyclodehydrogenations of PAHs using appropriate test cases to form 5- or 6-membered rings. My goal was to understand more about molecular reactions under extreme conditions and thereby realize new synthetic pathways for new molecules. This dissertation describes the synthesis of several substrates and studies of their thermal cyclodehydrogenations. Chapter 1 presents the cyclodehydrogenations of [5]helicene and benzo[5]helicene to form 6-membered rings under flash vacuum pyrolysis (FVP) conditions. An observed rate difference established that an electrocyclic mechanism is favored in this case and disproved the radical cyclization and 1,2-hydrogen shift/carbene insertion mechanisms. Chapter 2 describes the cyclodehydrogenations of phenyl-substituted phenanthrenes to form 6-membered rings under FVP conditions. The radical mechanism is ruled out because of the rate difference. Chapter 3 shows the synthesis of 7-(9H-fluoren-9-ylidene)-7H-benzo[c]fluorene and its thermal cyclodehydrogenation to form 6-membered rings under FVP conditions. In chapter 4, the cyclodehydrogenations of phenyl-substituted anthracenes and phenanthrenes to form 5-membered rings under FVP conditions are presented. The unexpected dominance of phenyl loss suggests that radical mechanisms are occurring during the cyclodehydrogenations. Chapter 5 describes the cyclodehydrogenations of [4]helicene and benzo[4]helicene to form 5-membered rings under FVP conditions. The results point to a carbene cyclization mechanism, in competition with the radical mechanism. / Thesis (PhD) — Boston College, 2008. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

Thesis (M.Sc.)--University of the Witwatersrand, Faculty of Science (Chemistry), 1990 / Deactivation studies; making use of fixed bed reactors, wet chemical analysis, surface area, pore volume determinations and X-ray diffraction—, scanning electron microscope— and secondary ion mass spectrometry techniques; were performed on a low temperature iron Fischer—Tropsch catalyst. It was revealed that this catalyst is mainly deactivated by sulphur poisoning, oxidation of the catalytic reactive phases, sintering of the iron crystallites and to a lesser extent deactivation through fouling of the catalytic surface by carbonaceous deposits. It was found that the top entry section of the catalyst bed deactivated relatively fast, the bottom exit section also deactivated, but not as fast as the top section The central portion of the catalyst bed was least affected. Sulphur contaminants in the feed gas, even though present in only minute quantities, results in a loss of catalyst performance of the top section of the catalyst bed, while water, produced as a product from the Fischer—Tropsch reaction, oxidized and sintered the catalyst over the bottom section of the catalyst bed.