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In this study, an isotope dilution method specifically designed to detect anaerobic methane oxidation (AOM) in methanogenic wetland soils was developed.  A range of anaerobic soils and sediments were screened for AOM potential.  Methane and carbon dioxide emissions were investigated in strictly anoxic microcosms to which ¹³C-labelled methane was added, and changes in the concentration and ¹²C/¹³C isotope ratios of methane and carbon dioxide were subsequently measured and used to calculate the separate components of the methane flux.  The results indicated that certain soils can oxidise methane oxidation anaerobically.  The clearest evidence for AOM was provided by minerotrophic fen soil (pH 6.0) in Bin Forest, which is derived from ultra-basic and serpentine till.  In the Bin Forest fresh soil anoxic microcosms, net consumption of methane was observed, and the amount of headspace ¹³C-CO₂ increased at a greater rate than the ¹²⁺¹³C-CO₂, further proof of methane oxidation.  Net methane production was observed in soil from Murder Moss, an alkaline site, pH 6.5, with a strong calcareous influence, but the ¹³C-CH₄ and ¹³C-CO₂ data indicated co-occurrence of AOM in this soil.  Anaerobic methane oxidation was not observed in the other, lower pH soils.  There was no evidence that amending anoxic slurries with up to 5.0 mM sulphate or  nitrate solutions promoted anaerobic methane oxidation.  Overall, this study provided good evidence for anaerobic methane oxidation in some wetland soils, and suggested that models predicting methane flux from wetland soils to the atmosphere could be improved by better understanding of the process.

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A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Masters of Science in Engineering. / The partial oxidation of methane by air to synthesis gas over supported cobalt catalysts was studied. The investigation included analysis of the products of this reaction at various temperatures, and of the structure of the catalysts using powder X-ray diffraction techniques. (Abbreviation abstract) / Andrew Chakane 2018

A dissertation submitted to the Faculty of Engineering, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Masters of Science in Engineering. / The partial oxidation of methane by air to synthesis gas over supported cobalt catalysts was studied. The investigation included analysis of the products of this reaction at various temperatures, and of the structure of the catalysts using powder X-ray diffraction techniques. The most effective catalyst for this reaction was found to be metallic cobalt supported on rhombohedral alumina (prepared as lO%Co/C/'r-A103)' In the presence of this catalyst 96% of tile feed was completely converted to synthesis gas (CO: 2H2) at lOOO°C. This catalyst showed no evidence of coking or loss of activity at lOfO°C over a period of 180 hours. The reaction mechanism is thought to occur in two stages over two distinct zones of the catalyst, Complete reaction of O2 with CH4 to form CO2 and H20 is followed, in the second stage, by reforming and the water gas shift reaction to produce synthesis gas. / Andrew Chakane 2018

by Jonathan Chun-kit Lau. / Thesis (M.Phil.)--Chinese University of Hong Kong. / Bibliography: leaves 56-66.

A variety of approaches, spanning a range of spatial and temporal scales, were applied to the investigation of the effects of low dose SO₄^2- deposition, at rates comparable to those experienced in acid rain impacted areas, on methane (CH₄) emissions from natural wetlands. Over two years of experimental manipulation of SO₄^2- deposition to a peatland in northeast Scotland, CH₄ emissions were suppressed by around 40%. There was no significant difference in suppression of CH₄ flux within the sol- deposition range of 25-100 kg-S ha^-1yr^-1. In a similar short-term controlled environment SO₄^2- manipulation experiment, the suppressive effect of SO₄^2- was found to be independent of the simulated SO₄^2- deposition rate within a range of 15-100 kg-S ha^-1yr^-1. The possibility that suppression of CH₄ fluxes may have been the result of a 'salt effect' was ruled out. Both temperature and water table controlled the extent of CH₄ flux suppression in acid rain impacted wetlands. Sulfate reduction potential in SO₄^2- treatments were found to be 10 times larger than in control plots, suggesting that long-term suppression of CH₄ fluxes is the result of the formation of an enlarged population of competitively superior sulfate reducing bacteria. SO₄^2- concentrations were smaller in peat pore water from SO₄^2- treatments than from controls. This is possibly the result of a stimulated SO₄^2- reducing community scavenging available SO₄^2-, thereby decreasing concentrations to below ambient levels. In northern peatlands (>50°) the effect of SO₄^2- deposition at 1990 rates may have been sufficient to reduce emissions from these systems by around 15% annually. Globally, the effect of acid rain SO₄^2- deposition may be sufficient to reduce CH₄ emissions by as much as 22-28 Tg by 2030, which places this interaction within the same size category as many other components of the global CH₄ budget that have received far greater attention.