Thesis (M.A.)--West Virginia University, 2001. / Title from document title page. Document formatted into pages; contains iv, 18 p. Includes abstract. Includes bibliographical references (p. 14-16).

Northern regions account for approximately 30% (1035 Pg) of the world’s soil organic carbon (SOC). Much of this carbon is currently stored in permafrost soils, which are vulnerable to increasing air and ground temperatures. Permafrost landscapes rich in ground ice, such as high-centred polygonal terrain, are likely to be highly vulnerable to thaw. Degradation of ice wedges in high-centred polygonal terrain causes increased moisture and ground temperatures. These environmental controls are likely to have a large impact on carbon cycling in this terrain type. My M.Sc. research combined both lab and field-based analyses to investigate current and potential carbon emissions from high-centred polygonal terrain in the Tuktoyaktuk Coastlands. To estimate the magnitude of future emissions from this terrain type I incubated six permafrost cores collected at two sites. Peat cores from four depths were each incubated under four conditions (cold anaerobic, warm anaerobic, cold aerobic, warm aerobic). The observation that carbon mineralization rates do not vary with depth demonstrates that the soil carbon liberated from permafrost in high-centred polygonal terrain will not be limited by SOC quality. This experiment also shows that emission rates will be moderated by temperature and moisture levels, and will be primarily in the form of CO2. To examine the impact of ice-wedge thaw on carbon emissions in high-centred polygonal terrain, we combined opaque chamber measurements of flux and estimates made from water samples using a gas diffusion model. Field sampling at two sites contrasted carbon emissions from polygon centres (n=18), wet troughs (n=18) and ponds (n=20). We also measured ground temperature and soil moisture using thermistors and a moisture sensor. Our field results demonstrate that ice-wedge degradation results in increased ground temperature, deeper active layers, and increased CO2 and CH4 emissions. Contrary to our expectations, CO2 emissions were not limited by waterlogged conditions, demonstrating the importance of anaerobic CO2 production. Our field measurements demonstrate that increasing temperatures are correlated with rising CO2 emissions in aerobic environments, and rising CO2 and CH4 emissions in anaerobic environments. Taken together, these two studies demonstrate that as ground temperatures increase in high-centred polygonal terrain, carbon emissions from ecosystem respiration are likely to increase. / Graduate / 0481 / 0425 / 0768

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M.Sc. (Chemistry) / Please refer to full text to view abstract

To avoid environmental pressure from water authorities, specifically regarding nitrogen and sulfate limits in tannery wastewater, modifications to existing deliming processes have been made. Conventional ammonium salt deliming methods contribute to Total Kjeldahl Nitrogen values in the region of 0.5 – 1.0g/L (33-67% of total TKN). Sulfate levels are increased with the use of organic deliming and ammonium sulfate deliming to the extent of 0.9g/L (27% of total sulfate). To understand the dynamics and kinetics of carbon dioxide equilibrium, the movement of carbon dioxide into deliming water, through carbonic acid, bicarbonate and ultimately into carbonates at liming or early deliming pH was studied. It was shown in this study that effective lime removal, at optimum conditions, resulted in fully delimed pelts at highly comparable quality and times compared to conventional ammonium salt deliming

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This investigation was initiated to study the effect of CO₂ on phytochrome-mediated morphogenesis in flowering and seed germination. Removal of CO₂ by flushing the plant environment with CO₂-free air inhibited the red light interruption effects on flowering in Xanthium pennsylvanicum and on seed germination in Lactuca sativa cv Grand Rapids. Further experiments were done to investigate the involvement of CO₂ exchange in the effects of night interruptions on flowering in Xanthium. ¹⁴CO₂ feeding trials showed that red light given for 5 minutes caused a net increase in ¹⁴C activity in the ethanol soluble fraction when ¹⁴CO₂ was fed during the light treatment. There was no effect of red light on the extent of ¹⁴CO₂ fixation in the dark period immediately following red light. The types of free amino acids recovered after paper chromatography were essentially the same after ¹⁴CO₂ feedings in darkness, red light, and far red light following red light. However, there was a considerable increase in ¹⁴C activity in most of the amino acids in leaves given red light interruption, and the amount further increased when far red light was given following the red light. The extent of ¹⁴C label in tyrosine, valine and leucine was essentially the same in all the three treatments. In CO₂-exchange experiments using the IRGA, brief red or far red light treatments were applied to Xanthium plants under inductive dark periods and the subsequent flowering response was assessed according to bud morphology. The occurrence of flowering depended on the timing, wavelength and intensity of the light treatments, and on the CCL concentration during the light treatments. CO₂ exchange was measured during the night interruptions in single attached leaves. CO₂ exchange was influenced by the conditions during the night interruptions, but there was no apparent correlation between the pattern of CO₂ exchange observed and the subsequent flowering response. It appears that the action of during night interruptions is not associated with the exchange of during the night interruption. In an attempt to investigate other possible roles of CO₂, experiments were done with light sensitive lettuce and Amaranthus retroflexus L. seeds. These experiments pertained to changes in pH of the incubation medium and CO₂ concentration simultaneously. Germination was strongly promoted at pH 4.0 but the promotion diminished with increases in pH and did not occur at pH 7.5. The response of germination to red irradiation was suppressed by CO₂ removal and enhanced by CO₂ enrichment in air or atmospheres. There was a close similarity between the pH effects on percentage germination and pH dependence of the CO₂ /HCO₃ - equilibrium. Transfer experiments, in which lettuce seeds were exchanged between buffers of pH 4.0 and pH 3.0, showed that the red/far red photo-transformation of phytochrome v/as independent of pH. Low pH, however, was required for onset of germination following red irradiation. Thereafter, pH between 4.0 and 8.0 did not limit the progress of germination. It is postulated that following red irradiation, a product develops which is distinguishable from the Pfr form of phytochrome. The product is stable at pH 8.0 and at pH 4.0 it acts to promote germination. / Science, Faculty of / Botany, Department of / Graduate

M.Sc. / An Acinetobacter sp. strain RFB1 isolated in our laboratory has been shown to have the ability to metabolise inorganic cyanide salts, CO 2, and bicarbonate. The enzyme aggregate responsible for the conversion of these substrates, is located extra-cellularly. Resolution of the extra-cellular complex, a crude enzyme filtrate, was attempted in order to characterise the protein responsible for the reduction of CO 2. The crude enzyme filtrate was separated by means of molecular exclusion chromatography and afforded three fractions with molecular masses ranging from 76 000 to 191 000. Analysis by SDS-electrophoresis, showed that the first protein fraction contained more than ten proteins. Certain of these proteins were identified in the second fraction and other proteins in the third protein fraction. This implies that some denaturation already occurred during molecular exclusion separation. The functionali7ation of CO 2 by protein fractions 1 and 3 supports this argument, and, in addition , cyanide ions were only reduced by fractions 1 and 2. Fatty acids, ranging with chainlengths between C5 and C25, were shown to be present and certain fatty acids were unequivocally identified by GC-mass spectroscopy as the products resulting from CO2 functionali7ation and carbon-carbon bond formation. Ferrous ions, in an optimal concentration of 250 gg cm', were necessary and served as an essential ingredient of the reaction mixture. A rather unusual result was, however, that apart from an initial, relatively small uptake of Fe(II), significant amounts of Fe(III) were not formed and the Fe(II) concentration remained approximately constant during the reaction. This implies that the formed Fe(M) is rapidly reduced to Fe(II) again. Spectroscopic measurements, furthermore, strongly suggested the involvement of an iron-sulphur cluster in a cyclic redox process wherein both Fe(II) and Fe(III) are involved. Carefully conducted experiments pointed to light as the outside source of energy. Qualitative similarities with an artificial photosynthetic process, formulated earlier by J-M. Lehlliii, can be drawn and used partly to explain the experimental results.

CO2 is generally regarded as a waste product. However, the efficient catalytic reduction of CO2 means that this concept can change to viewing this molecule as a feedstock to produce chemically valuable products. The catalytic reduction of CO2 is a challenge because of its stability, and its reduction into chemically valuable products requires an appropriate catalyst and accessible energy source. While second and third row transition metals have shown considerable promise as photocatalysts for the reduction of CO2 to CO, one of our goals is to elaborate on the metal centers and the ligand environments in order to discover new catalysts and processes. These efforts have revealed new photocatalysts based on manganese and rhenium supported by κ2-PN phosphinoaminopyridine ligands. This thesis will describe the synthesis and characterization of these catalysts and their CO2 reduction parameters. The selectivity of these catalysts for either CO or HCOOH will be explored. Furthermore, ligand modifications and their effects on the catalyst behaviour will also be presented.

The objective of this thesis is to explore the properties of supercritical carbon dioxide (CO2). In addition, the feasibility of building a small-scale low cost system will be explained. A supercritical fluid is a fluid which exhibits properties between liquid and gas with liquid like densities and viscosities similar to a gas. Since the discovery of supercritical fluids in 1822, the use of supercritical fluids, specifically supercritical CO2, has grown in popularity. The application of supercritical CO2 has continued to grow in industrial applications since the 1970’s. Supercritical CO2’s has many beneficial properties as a “green” solvent. Supercritical CO2 as a solvent is able to be implemented in a wide range of applications from aerospace, microchip manufacturing, food production, biomedical, pharmaceutical, dry-cleaning, and many more. This thesis project included designing, building and testing a supercritical CO2 extraction apparatus that examines the use of supercritical CO2 as a solvent in the extraction process of decaffeinating coffee. Due to the fact that supercritical CO2 requires high pressure operating conditions, the apparatus design is important not only for function but also for safety. In the description portion of this paper, design considerations related to each component’s function and their specific roles in the overall system are clearly stated. Furthermore, the build process is outlined along with the overall step-by-step operation of the apparatus. Different methods of data measurements are taken while the system is running, in order to interpret the apparatus’ overall functionality. Through the exploration of this experimental data, the results were compared between different operating parameters. In order to determine the feasibility of the supercritical apparatus, the devise was tested by applying the supercritical CO2 as a solvent for the extraction of caffeine from coffee beans. Analysis of the analytical data recorded from experimental testing confirms that the apparatus produced supercritical CO2. After testing specific operating conditions, it is proven that the supercritical CO2 is able to function as a “green” solvent in this small-scale system. The experimental results from these analytical runs are compared with theoretical maximums in order to determine the efficiency of the devise. Lastly, the paper presents an overview including lessons learned from the design process and from the information gathered. Data from experimental testing is interpreted and the system design is reevaluated with suggestions for future improvements.