Thesis (M.A.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (June 26, 2007) Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2000. / Vita. Includes bibliographical references (leaves 328-349).

This work investigated the consequences of vegetable oils spills in salt marsh sediments. The role of autochthonous bacteria in the oils degradation and degradative pathways were also studied 'in situ' and 'in vitro'. Simulated spills of sunflower and linseed oils revealed that both oils penetrated the sediments at a rate of 10-7 CM2 s-1. However, whereas 60% of the linseed oil had disappeared from the sediments after 2 months most of the sunflower oil remained after 6 months. Differences were noted in the adsorption of the oils to sediment particles and the depth at which they accumulate and these factors most likely influenced the route of the oil degradation and the sediments properties such as permeability. The contamination of the sediments with vegetable oils lead to a noticeable reduction in the abundance of plant roots and infauna. The abundance of aerobic, anaerobic and sulphate reducing bacteria in the sediments was increased by the addition of both oils, with linseed oil supporting greater bacterial density than sunflower oil. During the course of the experiment the relative abundance of oil degrading bacteria also increased. As a consequence of the increased bacterial activity, the sediments pH and Eh decreased and anoxic conditions were established, earlier in the case of linseed than that of sunflower oils. The degradation of the oils appeared to be a sequential process, initiated by the aerobic and/or anaerobic bacteria and continued by the sulphate reducing bacteria which themselves where unable to utilise the raw oils. The original composition of both oils underwent alterations mostly associated with their main fatty acid: the concentration of 18: 3(o3 and 18: 2o)6 in linseed and sunflower oil, respectively, decreased whereas that of the remaining fatty acids increased. As a result of the bacterial degradation of the vegetable oils 'new' fatty acids were detected and their identification was attempted using GC-MS analysis of their picolinyl and methyl esters. Various degradative pathways of linseed and sunflower oils involving the formation of the 'new' fatty acids are suggested with isomerisation, hydrogenation and P-oxidation as the primary routes for the degradation.

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This study was a replication of Fitzpatrick and Rubin's study of response strategies used in crisis communication. It differed though, in the type of crisis analyzed. While Fitzpatrick and Rubin studied cases of sexual harassment, this study examined oil spills of two supertanker groundings. Both the Exxon Valdez and the Sea Empress groundings, and especially Acomarit and Exxon, the companies responsible were examined by using content analysis. Units of analysis were statements by each company's spokesperson covered in either four American or four Norwegian newspapers. These statements were then categorized as one of four response strategies defined by Fitzpatrick and Rubin which were as follows: (1) The traditional public relations strategy, (2) The traditional legal strategy, (3) Mixed strategy, and, (4) Diversionary strategy.On behalf of these response strategies the study stated two hypotheses:H1: The spokespersons of Acomarit used the traditional public relations strategy significantly more than the traditional legal strategy, as defined by Fitzpatrick and Rubin, in Norwegian newspapers.The hypothesis was accepted.H2: The spokespersons of Exxon used the traditional legal strategy significantly more than the traditional public relations strategy, as defined by Fitzpatrick and Rubin, in American newspapers.The hypothesis was partially accepted.The study used an American and a Norwegian coder to secure reliability. Holsti's coder reliability test yielded eighty percent for the American statements, and seventy percent for the Norwegian statements.The study also indicated that the traditional public relations strategy was the most used response strategy. This was different to what Fitzpatrick and Rubin found in their study. They found the traditional legal strategy was used the most in cases of sexual harassment.However, both Exxon and Acomarit used the traditional public relations strategy more than the traditional legal strategy, but differed significantly in their use of mixed strategy and diversionary strategy. Exxon was found to have used the diversionary strategy significantly more than Acomarit. The researcher indicated that this may have been one of the contributing factors which lead to Exxon's public relations nightmare. In addition, Exxon was found to have used more spokespeople than Acomarit, which in turn may have made it difficult to centralize the information flow. / Department of Journalism

Marine pollution resulting from oil spillage has received much attention mostly due to the damaging effects it has on fisheries and aquacultures. One component of oil that is widely studied due to its toxic and carcinogenic properties is the polycyclic aromatic hydrocarbons. The physical and chemical properties of these compounds control their distribution into the various phases of the environment. The rates of elimination of these compounds from impacted organisms were investigated in laboratory and field experiments using selected marine organisms (Mytilus edulis and Salmo salar). The elimination of individual PAH compounds followed first order kinetics. Elimination rate varied among compounds and generally decreased with increase in molecular weight and degree of alkylation. Elimination rate constants (k2) and biological half-lives (t1/2) evaluated from chronically exposed mussels (collected from Aberdeen harbour) in separate laboratory and field studies were comparable but differed from those evaluated from acutely exposed mussels. Shorter t1/2 were obtained from acutely exposed mussels. The t1/2 ranged between 0.5- 22 d (acute exposure) and 3.8- 31.5 d (chronic exposure).The longer apparent t1/2 calculated for the chronically impacted mussels was attributed to the retention of the compounds in a stable compartment due to long period of exposure that limited exchange with the surrounding water. Contrary to expectation, t1/2 for similar compounds was higher in salmon than in mussels. The reason for this was unknown but attributed to the route of elimination. A good correlation (r2 > 0.72) was found between PAHs tissue concentration and taint intensity in salmon. Comparison of the results from this study with literature data showed that tank water replacement time and exposure duration affects rate of PAHs elimination. The data generated in this study and some of the reviewed studies will find application in different oil spill scenarios. The usefulness and limitations of the n-alkanes profile, PAH distribution and concentration ratios, and specific biomarker ratios from organisms in oil spill source identification was also demonstrated.

Aromatic hydrocarbons are a prevalent constituent of crude oil. The refined products of crude oil such as petroleum and diesel can find their way into groundwater though oil-spillages and are also present in the oil and gas industry’s produced water. These aromatics are biorecalcitrant, however upon ingestion with water, may be metabolised to toxic intermediates that are carcinogenic or mutagenic in nature. Although some treatment technologies are available most of these are under development and are yet to be proven in the field. This illustrates the need for novel, economical and environmentally friendly technologies to be developed with a view to remediating aqueous systems that have been polluted with aromatics hydrocarbons. The supramolecular cyclodextrin molecule, with its hydrophobic interior and hydrophobic exterior seems to be an excellent molecule for the trapping of the pollutant molecules, however the inclusion complexes with this cyclic sugar are water-soluble therefore there is a need for the cyclodextrin to be rendered waterinsoluble. A study of the aqueous solubilities of some aromatic hydrocarbons that may be present in crude oil has been carried out and shows that the majority of these molecules have a degree of water solubility that may increase upon environmental weathering. The successful reaction between a solid-phase resin and the β-cyclodextrin molecule has been achieved, with the total dryness of the system being required including Soxhlet extraction of the resin with anhydrous acetone before the reaction. The reaction between β-cyclodextrin and a range of isocyanates proved unsuccessful, but a range of symmetrical aryl ureas were synthesised from their isocyanates with the influence that different activating or deactivating groups on the ring have on the propensity to form the ureas being shown. The successful alkylation between β-cyclodextrin and a series of haloalkanes has shown the effect of increasing chain length on the degree of alkylation. This reaction involved the deprotonation of the cyclodextrin by sodium hydride in anhydrous dimethyl sulphoxide followed by reaction with the alkyl iodide. Increasing the equivalents of hydride or iodide, or the reaction time did not have a noticeable effect on the degree of reaction indicating that steric constraints were limiting the degree of reaction. Testing several of these alkyl iodides gave an indication as to their tendency to uptake and remove several model pollutants that had been dissolved in water with the propylated β-cyclodextrin displaying potential for the remediation of aqueous systems that had been polluted. Several of these results were very promising leading to the conclusion that further derivatives of these alkylated sugars may be even more suitable for future research into the remediation of organically polluted aqueous systems.

Salt marshes are one of the most difficult environments to remediate due to their sensitive and important ecosystems. Traditional cleanup methods can do more harm to the marsh than the oil itself. Bioremediation is the preferred cleanup approach for these delicate environments. Typically bioremediation has been carried out by the addition of nutrients but the results have been inconsistent. Previous laboratory studies conducted in oiled seawater demonstrated that clay minerals enhanced microbial growth and hence oil degradation. However, this had not been tested at field sites or on oiled marine sediments where oil is known to persist. The main objectives of this research were to test clay minerals as a bioremediation alternative for enhancing degradation of oiled salt marsh sediments and evaluate the geochemistry of sediment profiles for heavy metal enrichment. Laboratory experiments were carried out to evaluate the application of montmorillonite or kaolinite clay minerals on salt marsh sediments impacted by diesel oil. Oil biodegradation in control experiments was significantly more successful than in clay amended experiments. Clay minerals may have caused an increase in pH which inhibited enzyme-catalyzed processes required for metabolism. Field experiments were carried out in control and clay treatment plots in Louisiana salt marshes impacted by the Deepwater Horizon oil spill. In this research it was demonstrated for the first time that biodegradation of n-alkanes and PAHs was significantly enhanced by the addition of montmorillonite compared to controls. Vegetated treatment plots were slightly more effective than non-vegetative treatment areas. It is suggested that bivalent cations adsorbed to montmroillonite’s surface suppressed the diffuse double layer. This allowed the oil along the clay’s surface to be accessible to the bacteria where oil could be readily consumed. Clay minerals may serve as a new and unique bioremediation strategy for oiled salt marsh sediments. Geochemical sediment profiles from Louisiana salt marshes showed elevated concentrations of selected heavy metals (Zn > Cu > Pb > V > Cr > Fe > Ni). The Deepwater Horizon oil spill is a likely source of metal enrichment as many of these same metals are also constituents of the Deepwater Horizon oil.