The wastewater treatment process is one of the most important processes which contributes to the protection of the environment. This process can also potentially recover necessary and scarce raw materials, such as phosphorus. Research of the wastewater treatment technology is an increasingly relevant topic and more innovative knowledge should be gradually implemented into existing plants. However, the implementation of such technology involves increased investment and often operating costs. This is, why there is a growing interest in improving the energy intensity and hydraulic efficiency of the installed wastewater plant machinery. The optimization of operating parameters in such machinery can also bring significant savings, which can be potentially re-invested into other technologies. This work deals with the issue of proper evaluation of installed machinery for the selection of operating parameters and assessment of their significance. As the challenge, wastewater treatment technology is very sensitive towards the combination of technological equipment and incorrect operational parameters can lead to erroneous evaluation of the efficiency of individual equipment or inappropriate engineering proposals. To eliminate these risks, an analytical procedure for the selection and evaluation of parameters is proposed in this work. This procedure is demonstrated on six types of equipment. To verify the conclusions of the proposed procedure, a model design of the equipment was performed, in which the influence of individual parameters was concisely assessed. By using the data, the proposed procedure could be validated more specifically. In this work, the necessary data for the design was obtained by experimental research and extensive testing. The results confirm the practical applicability of the proposed procedure.

PhD (Geography) / Department of Geography and Geo-Information Sciences / Improved access to modern affordable, sustainable and reliable energy supply is fundamental in the development of any economy and in the achievement of sustainable development goals. However, energy as a resource is increasingly and becoming scare in many countries and subsequently expensive, with a substantial impact on the socio-economic progress, especially in any country that lacks the financial, physical, social and human capital to secure its energy supply. Energy can also be produced though the anaerobic fermentation of biological waste, such as animal excrement, which is methane-rich. Fermentation also produces a nutrient-rich digestate. Biogas can be used for domestic purposes, such as cooking and heating. Furthermore, it can be converted into electricity. Biogas technology is of particular significance in rural households, where energy crisis are common. This thesis therefore aimed at developing an adoption and sustainable utilisation framework of biogas as an alternative source of energy for greenhouse gases emission reduction in the Limpopo Province. The sample involved 72 households with biogas digesters, which were purposively sampled and 128 households without digesters, which were randomly selected. The study was based on the primary data that were elicited using open and closed-ended questionnaires. Empirically, the results of this thesis developed a sustainable, simplified, appropriate and comprehensive framework for biogas adoption and utilisation, including an analysis of important factors that could influence the adoption of this desired technology, for cost-effectiveness and sustainability. / NRF