Please read the "Background" (p v) in the section 00front of this document Copyright 2002, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Bartie, C 2002, The life and career of the South African dramatric soprano Marita Napier, DPhil thesis, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-11142007-125718 / > / Thesis (DPhil (Microbiology))--University of Pretoria, 2007. / Microbiology and Plant Pathology / unrestricted

A manganese ore dump and oil tank farm have been situated in the Port Elizabeth harbour for more than forty years. Although these facilities are independently operated and managed, they are viewed as one distinct disamenity, and there is strong local opposition to their continued location in the harbour. The negative environmental impacts (for example, water and air pollution) caused by the ore dump and tank farm have been well documented. This pollution takes the form of oil leaks from the oil tank farm, and ore dust pollution from the manganese ore dump. The air pollution caused by the manganese ore dump is a result of the dump currently being an open air handling and storage facility. The ore dust is dispersed into the air due to strong prevailing winds in the Bay and has resulted in respiratory illnesses of residents living in close proximity to the facility. Oil pollution, due to leakages experienced at the oil tank farm, has extended far beyond the periphery of the harbour. Inter alia, there has been a decline in local fish populations, as well as a decline in passive and active use satisfaction associated with the adjacent beach area, i.e. Kings Beach. These oil leakages, first reported in 2001, could have a detrimental effect on the Blue Flag status of this beach, as well as the Blue Flag status of other beaches situated further up the coast. The lease agreements for the oil tank farm and manganese ore dump are set to expire in 2014 and 2016, respectively. As yet, there is no consensus on when these disamenities will be (re)moved. In order to mitigate the secondary impacts of these facilities, both of them should be removed. Although these impacts should be the focus of public policy debates and cost-benefit assessments, no direct valuation method exists to value the economic cost to affected communities. Instead, non-market valuation methods, such as the contingent valuation method (CVM), are often applied to assign values to these economic costs. This study seeks to determine Nelson Mandela Bay households‟ preferences for the immediate removal of the manganese ore dump and oil tank farm from the Port Elizabeth harbour. This case was selected since it represents a current public policy debate issue that has not been resolved. Monetary estimates of people‟s preferences for the removal of pollution-creating activities can assist policy-makers and other stakeholders when locating industries in an urban setting. These estimates can also be of use in understanding the benefits associated with air and water quality improvement projects. The primary valuation technique used in this study is the CVM. This method was chosen as it is capable of measuring the economic significance of lost passive-use values of individuals affected by negative externalities. Both a non-parametric and a parametric estimate of mean willingness-to-pay (WTP) were derived. On average, a respondent was willing to pay a once-off amount of between R47.09 (non-parametric estimate) and R93.21 (parametric estimate). Non-parametric estimation (via the Turnbull estimator) was conducted to test the sensitivity of the parametric results (via a logit model). The logit model‟s results showed that the probability of a „yes‟ answer to the referendum question varies with a number of covariates in a realistic and expected way, which offers some support for the construct validity of this CV study. Household income, education, age, and disamenity awareness were significant determinants of individuals‟ responses to the WTP question. A summary of the findings of WTP estimates for both parametric and non-parametric analysis is provided in Table 1. Three primary recommendations stem from this study. Firstly, the study used a relatively small sample size. Although it was sufficient for a pilot study it is recommended that future research into this issue should aim for a much larger sample size to ensure more precise estimates of the WTP for the removal of the disamenity. Secondly, the conservative non-parametric mean WTP estimate should be used as opposed to the higher parametric mean WTP estimate. Third, the aggregate WTP estimation constitutes only a partial analysis of cost. A number of other factors and value streams need to be analysed and compared with the cost estimates generated by this study if adequate holistic decision-making is to take place with regard to the removal of the manganese ore dump and oil tank farm. More specifically, the total WTP estimated in this study should be viewed as only one input into a comprehensive social cost-benefit analysis to determine the desirability of the removal of this disamenity for wider society.

Ph.D. (Chemistry) / In this study, carbon based electrode materials such as glassy carbon, graphene, diamond and exfoliated graphite were explored as suitable electrode materials for electrochemical detection, electrochemical and photoelectrochemical degradation of organic water pollutants. Graphene modified glassy carbon electrode sensor was developed for bisphenol A. Cyclic voltammetry was used to study the electrochemical properties of the prepared graphene- modified glassy carbon electrode using potassium ferricyanide as a redox probe. The prepared graphene- modified glassy carbon electrode exhibited more facile electron kinetics and enhanced current of about 75% when compared to the unmodified glassy carbon electrode...

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La thèse consiste à développer une technique d'imagerie quantitative de concentration de polluants dans les écoulements réactifs. Il s'agit d'une part de développer l'imagerie de fluorescence sur NO. Un modèle de fluorescence à n niveaux a été développé pour calculer l'évolution de la fluorescence avec la température, concentration des espèces et pression. Ce modèle a été validé avec des mesures de fluorescence et d'absorption obtenues dans une cellule optique fonctionnant jusqu'à 800 K et 20 bar puis dans un brûleur laminaire haute-pression. De ce modèle a été définie une stratégie permettant la mesure de la distribution instantanée de NO dans une flamme stratifiée. Une étude similaire pour détecter CO a été ensuite initiée. Des mesures de fluorescence à deux photons ont été obtenues dans la cellule et dans une flamme plate atmosphérique. Les résultats montrent que cet outil est opérationnel, répondant à un besoin pour l'amélioration des performances des systèmes de propulsion. / This PhD work is to develop a quantitative imaging technique for measurements of the concentration of pollutants in reactive flows. On one hand, the concern was to develop the NO fluorescence imaging technique. For this purpose, an n-level fluorescence model was first developed to calculate the behavior of fluorescence signals with temperature, species concentration, and pressure. Then this model was validated with fluorescence and absorption measurements acquired in an optical cell up to 800 K and to 20 bar and in a high-pressure laminar burner. From this model, a strategy used to measure the instantaneous NO distribution in a stratified flame was defined. Then, a similar study to detect CO with fluorescence was then investigated. Two-photon fluorescence measurements were performed in the optical cell and in a flame. The results make clear that the spectroscopic diagnostic becomes operational with the need to improve the performances of propulsion systems.

Philosophiae Doctor - PhD / Wastewater is normally composed of a mixture of pollutants. The type and composition of pollutants in a particular wastewater depend on the source of origin. The source and characteristics of a particular wastewater determine the ideal method of sewage treatment. Specific treatment techniques are effective in the removal of certain types of pollutants and may have no impact on the levels of other types of pollutants. Therefore, a combination of treatments and assessment of the quality of effluent before release into the environment is normally recommended. The assessment of effluent can be achieved by various techniques including chemical analysis and biological assays. Chemical analyses are commonly employed; however, they often pose detection problems and are considered to be uneconomical.

Degradation of organic contaminants in wastewaters emanating from industrial processing plants could render the water streams reusable for the purpose of reducing water consumption while protecting the environment from harmful pollutants. Organic pollutants can be removed from water using biological processes that mineralise the organics to H2O and CO2. However, mineralisation by biological processes take a long time and in many cases, total mineralisation is impossible to achieve. Alternatively, organics can be completely degraded and mineralised rapidly using chemical and/or photocatalytic advanced oxidation processes (AOP). Both systems have some short comings. In chemical AOP such as Fenton and photo-Fenton reagents, the chemical agents used remain in the water as pollutants requiring further removal. In photocatalytic oxidation processes, most current technologies use UV light as an energy source. The chemical processes are environmentally incompatible, whereas, the “green” photocatalysis is extremely expensive due to the consumption of electricity by high pressure UV light. Forerunner investigators of photocatalysis utilised TiO2 as the photocatalyst of choice. It has major drawbacks of which the most important one is that it is only activated under ultraviolet (UV) light irradiation. This high energy consumption made the process practically unfeasible. Solar energy (natural light and heat from sun) has great prospects with regards to acting as a substitute for UV since it is a renewable and cheaper energy source. This work therefore investigated the development of a heterogeneous all-solid-state Z-scheme silver/ silver chloride/ bismuth oxychloride (Ag/AgCl/BiOCl) photocatalyst that is able to utilise natural light through being activated by visible light irradiation. This will successfully serve as a green alternative in the use of renewable energy for pollution reduction while saving energy. The synthesised photocatalysts were characterised using various techniques. The purity and crystallinity of the synthesised photocatalysts were determined using x-ray diffraction (XRD) while x-ray photoelectron spectroscopy (XPS) was used to determine the elemental composition and chemical states present in the synthesised catalysts as well as confirm the presence of elemental Ag. Fourier-transform infrared spectroscopy (FTIR) specified the functional groups present while the morphology and chemical composition were determined on a scanning electron microscopy (SEM)/ energy dispersive x-ray spectroscopy (EDS). The surface area and pore size were measured on a Brunauer-Emmett-Teller (BET) and thermogravimetric analysis (TGA) was done to determine the thermal degradation of synthesised particles. Ultraviolet-visible spectroscopy (UV-VIS) was done to determine the photoabsorption range and bandgap of the particles as efficiency of photocatalysis is dependent on the properties and morphology of the semiconductor material. Degradation studies were carried out under both visible and UV light irradiation in a batch reactor. The activity of the synthesised Ag/AgCl/BiOCl photocatalyst was compared to that of commonly used TiO2. Specifically, while 60% degradation was achieved under UV light irradiation by both TiO2 and Ag/AgCl/BiOCl photocatalyst, in visible light irradiation, TiO2 measures only 14% in 4 h while Ag/AgCl/BiOCl measures a photodegradation efficiency of 53%. Other factors such as initial organic contaminants concentration, initial catalyst concentration, pH effects and individual compounds effect were also investigated. The reusability of the catalyst was also reported showing stability of the synthesised catalyst as after a total irradiation time of 48 h, 65% phenol degradation was measured. The phenol degradation kinetics were found to fit the widely used first-order Langmuir-Hinshelwood model. The result from the current study proves the feasibility of a novel process for mineralisation of organic compounds in water under cost effective visible light irradiation for the removal of recalcitrant and refractory organics from water. / Dissertation (MEng)--University of Pretoria, 2019. / Chemical Engineering / MEng / Unrestricted

The analysis of organic pollutants in water is traditionally done following EPA procedures which commonly use liquid-liquid extraction. One liter of water is extracted three times with 60 mL of an organic solvent. The extract is concentrated and analyzed by gas chromatography. This procedure is time consuming and can cause losses of semi-volatile components, in addition to requiring a relatively large amount of organic solvent (180 mL). By performing the extraction directly in a GC autosampler vial using one milliliter of contaminated water and one milliliter of organic solvent, then injecting a large volume (~150 mL) of the organic layer taken directly from the vial by an autosampler, the same analysis can be done simpler, quicker, and with much less organic solvent (1 mL). / Master of Science

The accumulation of industrial contaminants in the natural environments have rapidly become a serious threat for human and animal life. Fortunately, there are microorganisms capable of degrading or transforming environmental contaminants. The present dissertation work aimed to understand the genomic basis of microbial degradation and resistance. The focus was the genomic study of the following bacteria: a) Pseudomonas fluorescens NCIMB 11764, a unique bacterium with specific enzymes that allow cyanide adaptation features. Potential cyanide degradation mechanisms found in this strain included nit1C cluster, and CNO complex. Potential cyanide tolerance genes found included cyanide insensitive oxidases, nitric oxide producing gene, and iron metabolism genes. b) Cupriavidus sp. strain SK-3 and strain SK-4. The genome of both bacteria presented the bph operon for polychlorinated biphenyl (PCB) degradation, but we found differences in the sequences of the genes. Those differences might indicate their preferences for different PCB substrates. c) Arsenic resistant bacterial communities observed in the Atacama Desert. Specific bacteria were found to thrive depending on the arsenic concentration. Examples were Bacteroidetes and Spirochaetes phyla whose proportions increased in the river with high arsenic concentrations. Also, DNA repair and replication metabolic functions seem to be necessary for resistance to arsenic contaminated environments. Our research give us insights on how bacteria communities, not just individually, can adapt and become resistant to the contaminants. The present dissertation work showed specific genes and mechanisms for degradation and resistance of contaminants that could contribute to develop new bioremediation strategies.

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