Faculty of Engineering and the Built Environment (ETDs)
Permanent URI for this communityhttps://hdl.handle.net/10539/37934
Browse
15 results
Search Results
Item Effect of pipeline pigging on raw water pipeline flow rate and energy consumption(University of the Witwatersrand, Johannesburg, 2024-02) Phillip, Neil Claude; Ndiritu, JohnPipeline pigging is a widely used method of pipeline cleaning to improve the hydraulic efficiency of a pipeline system, reduce deposits within a pipeline, reduce operational costs and improve water quality. With insufficient pipe cleaning, pipeline deposits accumulate within the pipeline which reduces the cross-sectional flow area of the pipeline and increases the friction losses in the pipeline. This subsequently reduces the operating flow rate, increases the pumping cost of the system, and reduces the water supply to the surrounding area. Therefore, the study aimed to investigate the hydraulic improvements and operational cost savings of a pipeline system after pigging and to determine when pigging should be done. A case study of the Tayside high lift pump station in South Africa was used for this investigation. Results indicate that pigging removes deposits and sediments from the pipelines thereby increasing the flow rate while reducing the cost of pumping substantially. The increase in flow rate calculated from the case study was 23.9% after one of the pigging operations in 2016. In addition, the pigging operations completed yearly also indicated a flow rate increase after pigging. The study showed that the increase in sediment levels of the raw water in the rainy season led to a reduction in the hydraulic capacity of the pipeline indicating an increase in sediment deposition in the pipeline. Life cycle cost analysis of the case study system obtained annual cost savings of R991,800.59 over a 50-year period. Based on the findings, a flexible routine for pigging based on the reduction in the hydraulic capacity of the pipeline is proposed to cater for the variability in levels of sediment in the raw water in alignment to the rainfall and streamflow patterns. This allows the pipeline to operate at the lowest energy cost and at the highest possible flow rate.Item Water for Firefighting in Sol Plaatje Municipality, Northern Cape, South Africa(University of the Witwatersrand, Johannesburg, 2023) Thage, Tumelo MacAurthur; Ilemobade, AdesolaIn South Africa, SANS 10090 (SABS, 2018a) and the Red Book (DHS & CSIR, 2019) recommend that for firefighting municipal water distribution systems must have and maintain the capacity to provide water for firefighting purposes. van Zyl & Haarhoff (2007) state that the provision of water for firefighting is a dominant design consideration as it influences the sizing and outputs of critical components. Scheepers (2012) argues that fire flows acts ‘as the most limiting demand condition’ as when it required it is extracted in large quantities for a short period. The most commonly used fire flow values in the SANS 10090 have largely remained unchanged for several decades. In other words, these values have not been revised to take account of the evolution of municipal water consumption over more than 30 years. This suggests that the recommended water requirements for firefighting may no longer be fit for purpose. The literature review revealed that the fire flows in the Red book violates the same in the SANS 10090 - this is illegal as the SANS 10090 specifies enforceable absolute limits. Furthermore, the Red book and SANS 10090 provide different fire risk classifications and values for the different parameters and as such, inconsistent and lack uniformity. It is important for design engineers to have accurate input data when planning and designing for fire flow requirements as any deficiency in basic design information could lead to an insufficient capacity to fight fires or an over-design of water supply infrastructure. A question arose from these observations, which provided inspiration for this study: Are fire flows in the SANS 10090 and Red book appropriate for current firefighting efforts? In answering this question, the first step of this study was to identify participating municipalities that were willing to release their datasets on firefighting for this study. Sol Plaatje municipality was one of the willing municipalities. This study thereafter categorised and analysed information contained in the 3236 fire incident reports that occurred within Sol Plaatje Municipality during the period 21 July 2017 to 21 August 2020, and compared actual fire flow volumes and flow rate data against the SANS 10090, Red book and previous South African studies. In order to provide context and aid better understanding of the datasets, structured interviews were conducted with municipal officials responsible for firefighting operations at Sol Plaatje municipality. Key highlights of this study indicated: ∼ 93.3% of fires in Sol Plaatje municipality were extinguished using 7 Kℓ or less of water. This result is similar to previous studies- In a 2014 study more than 90% of fires in 5 Western Cape Towns were extinguished using less than 10 Kℓ of water; In a 2019 study, 75% of fires in the City of Johannesburg were extinguished using less than 6.60 Kℓ of water; and In a 2022 study, 87% of fires in the City of Johannesburg were extinguished using 10 Kℓ or less of water. Overall, 75%-93% of fires were extinguished in the various study areas using 10 Kℓ or less of water. For large fires in Sol Plaatje municipality, the average water volume used to extinguish 85 large Category 2 fires was 8.56 Kℓ or less of water. This finding is similar to that of the Western Cape 2014 study and the 2022 City of Johannesburg study that found that 8.6 Kℓ and 9.63 Kℓ or less of water extinguished 77 and 89 large category 2 fires, respectively. What is evident from the results is that the volumes of water used in Sol Plaatje and previous studies are significantly less that the specified values in SANS 10090 and the Red book. An adverse consequence of higher values is that it leads to an over-design of water supply infrastructure as it increases the volume of municipal storage required for firefighting and consequently, increases the total capacity of municipal storage. Increased storage capacity increases resources that are expended, as well as water retention times, which negatively affects water quality. This study validates the recommendations of previous studies that the fire flows in the SANS 10090 and Red book need to be revised to enable the efficient conservation of scarce water resources and optimal design of water systems.Item Upgrading Semi-Soft Coking Coal by Hydrothermal Treatment: Caking and structural properties(University of the Witwatersrand, Johannesburg, 2024-02) Ndumo, Jabulile; Bada, SamsonBased on the current challenges faced by the metallurgical industry in South Africa in importing quality reductants, there is an urgent need to investigate a new approach to enhance the semi-soft coal available in the country. Importing prime coking coal has increased the steel price, resulting in many downstream operations involving steel closing down in the country. With a surplus of semi-soft coking coal in South Africa, this research sought to look into this kind of abundant coal to enhance its property as a reductant for blast furnace applications. For this reason, a study was conducted on two Southern African coals, Grootegeluk (semi-soft coking coal) and Moatize (higher quality coal). Both coals were individually hydrothermally treated and then blended at different ratios to further upgrade their metallurgical properties. The as-received Moatize coal showed properties that were more of prime coking coal with high total carbon content (76.50%), a crucible swelling index of nine, a maximum dilatation of 59% and volatile matter of 20.39%. It was a highly vitrinite coal with a vitrinite reflectance of 1.28%, a higher micropore volume than mesopore volume and a very low maximum fluidity of 24 dial divisions per minute (ddpm). According to the initial test, the Grootegeluk coal sample had a crucible swelling index of 5.5, a high volatile matter of 35.02% and a low vitrinite reflectance of 0.72%. In addition, the sample had a maximum dilatation of -10%, a maximum fluidity of 3ddpm and a higher mesopore volume than the Moatize coal. Hydrothermal treatment was conducted on the coal samples at numerous temperatures (100ºC to 200ºC), at various residence times (30 to 90 minutes) and at different coal masses (300 to 600grams (g)). According to the results, the optimal hydrothermal conditions were 200ºC, 90 minutes and 600g. Another hydrothermal treatment was performed at a higher temperature and residence time of 280ºC and 180 minutes. The same sample mass of 600g was used and the result showed no further improvement. The coal samples were then blended at various Grootegeluk/Moatize ratios (15% to 50% Grootegeluk), and further hydrothermal treatment tests were carried out based on the optimum conditions achieved. Both the hydrothermal test and the blending of the coal led to a coal with volatile matter ranging from 21.46% to 23.79%, which is a required specification for metallurgical application. The total carbon of the enhanced coal blend also ranged from 68.8% to 82.10%, with total sulphur below 1%. The mesopore-micropore ratio of the treated blend was higher than the individual coal samples, which is what is expected of a metallurgical coal. Based on these findings, coke was produced and analysed to identify a coke capable of withstanding blast furnace conditions. Using the particle reactivity index (PRI), proximate analysis and the pore size distribution, 90-(50% Grootegeluk+50% Moatize)-C product was identified as the coke with the least PRI and high fixed carbon. Further investigation showed that the blending and hydrothermal treatment affected the coal’s physiochemical, rheological and micro-molecular properties. The study has established that metallurgical properties of the locally mined semi-soft coking can be enhanced solely and when mixed with a hard coal. Even though the 90-(50%GG+50%M)-C did not meet the overall specifications required for use in the blast furnace, it was identified as a suitable reductant for other metallurgical applications.Item Alternative Tenure Options as a Stepping Stone for Urban Land Reform: The Case of Kwa Mai Mai Muthi Market(University of the Witwatersrand, Johannesburg, 2024-02) Mnguni, Thobeka; Maina, Miriam M.This research uses qualitative methods to investigate the case of the Kwa Mai Mai muthi market located in the central business district of Johannesburg where over the decades informal traders have converted their trading units into residential homes. This case is used to respond to the research question, ‘To what extent is taking administrative action to improve land tenure by offering communities rights to occupy urban land feasible and necessary for advancing the urban land reform agenda?.’ The research acknowledges that popular approaches to improving tenure by converting insecure tenure rights to statutory ownership through the Deeds office has had limited success and resulted in efficiencies due to the high costs and the resources intensive nature of this approach. Instead, the research recommends a necessary transition to improving tenure in innovative, context-specific ways that work to build on existing settlements through taking low-cost and low LOE administrative action.Item In the Era of Global Shocks: A Needs Inquiry on State Provided Housing During and After the Covid-19 Pandemic(University of the Witwatersrand, Johannesburg, 2024-02) Mogale, Lebogang Lucia; Klug, NeilSouth Africa, like many countries of the South is confronted by a housing crisis, especially in Metropolitan areas. This is because Metropolitan areas are experiencing rapid population growth and, in the process, creating a demand for low-income housing. The state-provided low-income housing, implemented as a remedial intervention, has faced spatial, procedural, and administrative scrutiny, among others. Furthermore, the Covid-19 pandemic has brought housing and human settlements into the spotlight, raising both opportunities and challenges with the resilience of state-provided low income housing. The study has used the onset of the Covid-19 pandemic to emphasize and make apparent the various types of housing and settlement needs that should be prioritised to potentially mitigate the impact of future global shocks such as pandemics. Global shocks trigger resilience thinking that is linked to spatial attributes that can potentially reduce and mitigate the impact of disasters and risks. This indicates an opportunity of supporting ‘resilience thinking’ with existing social realities. The study speaks to this gap by diving deep into theoretical discourses of housing needs and practical needs as determined by participants perceptions. This was done by adopting a case study design that follows Wilhelm Dilthey's philosophy of hermeneutics. The Case Study context used was Palm Ridge extension 10 where Breaking New Ground Housing and Military Veteran houses were allocated in November 2019. Interviews were conducted with both municipal officials and beneficiaries of subsidised housing to inquire in-depth about their considerations of housing needs and how they can be met. The findings of the study indicate that there is a correlation between what is perceived as housing needs during the pandemic and some principles of resilience thinking. It identifies two types of housing needs necessary for mitigation, coping, and recovery from the Covid 19 pandemic. The needs identified are technical housing needs which are concerned with the physical structure of a house and settlement, and soft dimensional housing needs which are more symbolic of the relationship residents have with their houses and the overall neighbourhood. Moreover, the study emphasises that the translation of housing needs from theory to practice is to a certain degree challenged by institutional deficiencies. Although state-provided housing is challenged, it has proven a resilient measure in the era of the pandemic when housing insecurities were on the rise. Neighbourhoods like Palm Ridge can potentially adopt evolutionary and transformative resilience due to their flexible nature to cater to changing needs. Therefore, it is apparent that needs inquiry is a complex issue that can be leveraged to stimulate the adoption and development of bottom-up and collaborative responses to shock mitigation.Item The relevance of industrial development zones as prototyping hubs for the diffusion and scale-up of green hydrogen power fuels for South Africa: A case study of Atlantis in Western Cape(University of the Witwatersrand, Johannesburg, 2024-02) Madhi, Fadheelah; Irurah, DanielIn South Africa, provinces such as the Western Cape (WC) enjoy high levels of renewable energy (RE) resources such as solar and wind energy while also experiencing critical transmission and storage constraints. On the other hand, industrial development zones (IDZs) such as Atlantis in the WC, offer opportunities for adaptable infrastructure in support of green hydrogen (GH) technologies that can convert surplus RE to GH which is rapidly evolving as a globally flexible power fuel. Through a qualitative study approach, the study assessed the relevance of IDZs as prototyping hubs for addressing the challenges facing the prototyping and scale-up of GH from RE resources which are commonly associated with intermittency. Primary data were collected through interviews with senior engineers (electrical, mechanical, and industrial) in RE and GH while secondary data were extracted from relevant studies and industry reports as well as policy and regulatory frameworks covering RE, GH and IDZs. As one of the initial findings, in spite of rapid evolution in RE-technologies and policies in South Africa and globally, key barriers still exist in the adoption and diffusion of GH-technologies. Five key barriers identified are infrastructure, socio-economic, economic, water scarcity for GH from electrolysis, policy, and regulatory constraints. Secondary data further indicates that SA is in the roll-out stage of two key GH initiatives (Green Hydrogen Valley - GHV and Sasol-Toyota GH joint venture) aimed at tackling the identified barriers. However, further analyses indicates that such prototyping projects would still leave major gaps that need to be closed in order to expedite the scale-up of GH nationally. The study then interviewed one Atlantis IDZ official on the extent to which IDZs could facilitate in closing the adoption and scale-up gaps for GH in South Africa. As a hub specifically created for the testing, prototyping and production of green technologies in order to facilitate their scale-up and adoption, the study finds that Atlantis IDZ is uniquely positioned for mitigating the barrier-gaps identified. The IDZ is equipped with secure streams of capital investments which could be leveraged for GH-technologies as well as for addressing related constraints such as water scarcity through desalination technologies. Atlantis also holds unique learning opportunities, operates under entrepreneurship-friendly special policies, and enjoys access to infrastructure relevant for the adoption and scale-up of GH. Based on these findings, the study concludes that IDZs are not only relevant for the national adoption of GH but also critical for positioning South Africa as a leading GH economy globally.Item An investigation on the impact of landownership dynamics in rural development: A case of Nooitgedacht area in Muldersdrift, Mogale City Local Municipality(University of the Witwatersrand, Johannesburg, 2024-02) Masonganye, Thoriso Obakeng; Sithagu, TakiSouth Africa's history of land ownership is deeply intertwined with the legacy of colonialism and segregation. In the contemporary context, land ownership has emerged as a pivotal catalyst for rural development, aimed at addressing historical injustices and fostering sustainable socio-economic growth. Despite numerous reforms and initiatives introduced since the dawn of democracy, challenges persist, particularly in rural regions like Nooitgedacht in the West of Gauteng. In Nooitgedacht, landlessness, underdevelopment, poverty, and minimal economic activity continue to plague the community. This study delves into the intricate relationship between land ownership dynamics and rural development, with a specific focus on Nooitgedacht within the Mogale City Local Municipality. To comprehensively assess this issue, a multi-faceted research approach was employed, incorporating primary and secondary data collection methods. The research methods encompassed a thorough desktop survey, the distribution of questionnaires to community members, and in-depth interviews with municipal officials and community stakeholders. The desktop survey harnessed municipal valuation data to discern the existing patterns of land ownership in Nooitgedacht, revealing a marked imbalance, with most of the land controlled by private individuals and businesses, while national, provincial, and local governments held relatively merger land ownership within the study area. This skewed ownership pattern underscores the profound challenge of land access in Nooitgedacht. Consequently, the area grapples with persistent land inequalities encompassing issues of access, ownership, distribution, and administration, which further manifest through ongoing threats of land invasions, evictions, limited development, and a dearth of economic activities. Despite the presence of municipal policies aimed at addressing these disparities, implementation remains sporadic, fragmented, and inadequately coordinated within the municipality, resulting in a sluggish delivery of rural development. In conclusion, the study underscores the pivotal role of land ownership in shaping the trajectory of rural development in Nooitgedacht. It is evident that without equitable and well-coordinated land ownership policies and practices, the goal of achieving sustainable rural development in this region remains an elusive aspiration.Item Exploring the effect of spatial planning in delivering access to socio-economic opportunities to address spatial inequality - The case of the Tswaing Mega Project and the Marikana-Soutpan community(University of the Witwatersrand, Johannesburg, 2024-02) Malope, Kgomotso Mirriam; Izar, PriscilaSouth Africa is challenged by persistent spatial inequality inherited from previous regimes, which contributes to various socio-economic challenges and hinders the sustainable development of urban areas. Consequently, poverty tends to be more severe in previously marginalised areas where poor residents, the majority of them being black, still suffer from a lack of proximity to adequate socio-economic opportunities (Harrison & Todes, 2013). Several urban and spatial policies have been adopted and implemented, but spatial fragmentation persists. The Department of Human Settlements proposed adopting Mega Projects to develop large-scale, new housing projects integrated with infrastructure, in greenfield sites which are located in urban peripheries. Mega Projects also aim at attracting private sector investment. However, this strategy has been criticised for disregarding planning ideals of compactness and integration with existing economic centres and job opportunities, and for putting forward plans that lack details (Ballard, 2017; Turok, 2015). Therefore, the objective of this study was to investigate how spatial planning and infrastructure investment could be used to promote access to socio-economic opportunities for marginalised people in spatially fragmented urban areas by focusing on the case of the Tswaing Mega-Project in the Marikana-Soutpan community in the periphery of the City of Tshwane. Unlike other Mega Projects designed on vacant land, the Tswaing Mega Project covers an already existing informal area, the Marikana-Soutpan informal settlement. Qualitative research methods informed the research, drawing from three types of primary and secondary data: (1) qualitative interviews, (2) documentation review and (3) participant observation. Research findings describe how the Tswaing Mega Project plan, launched in 2015, experienced delays and was eventually cancelled, with the adoption of the Upgrading of Informal Settlement Programme (UISP) in October 2022. Additionally, the long waiting period for government intervention and the lack of transparency from the government have proven to worsen the state of marginalisation for the Marikana-Soutpan Community. At the completion of this research project, the Marikana-Soutpan community is in for another, possibly long, waiting period as the UISP initiates. Therefore, this research speaks to the analysis that is critical of Mega Projects for offering poorly detailed project plans, lacking transparency, and lacking consideration of the complexities of human settlement development. Based on the findings, it is argued that the now-revoked Tswaing Mega Project has contributed to the further marginalisation of the Marikana-Soutpan community.Item Shopping Centres in South Africa: Urbanism Gets the Cold Shoulder. The reimagining of introverted shopping centres into responsive urban environments through design: the case of Menlyn Park Shopping Centre(University of the Witwatersrand, Johannesburg, 2024-02) Mentz, Reuben Frederick; Goncalves`, KevinShopping malls have nestled themselves into the urban fabric of cities, more specifically the suburban fabric, creating large non-interactive, introverted artifacts geared towards consumption and the maximisation of profits. These artifacts act as exclusive clubs where the membership requirements are money and a private vehicle. Menlyn Park Shopping Centre, a regional shopping mall neatly placed between three major regional roads and a national highway in the east of Pretoria, is no different. The mall, or rather the artifact, violates all principles of Responsive Environments and transforming the citizens of the city into customers. The purpose of this research is to explore ways to transform the introverted Menlyn Park Shopping Centre into a more responsive urban environment, an environment that does not turn its back on citizens, but rather welcomes interaction and variety. This overall objective is achieved by creating a research framework in order to create understanding of the nature of shopping malls in general, how they came to be, their functioning and the different types we encounter. An expert in the field of shopping mall design was also consulted, in order to provide some perspective on the future of malls and element to consider. This is followed by an analysis of the Menlyn Park Shopping Centre itself, unpacking the different elements and how they relate to principles of responsive urban environments. A conclusion is reached through an urban design framework, which proposes an alternative design for the shopping mall satisfying the principles of responsive environments.Item Socio-economic Perspectives in the Redevelopment of Hostels in South Africa: A Case of Wolhuter Hostel, Jeppestown(University of the Witwatersrand, Johannesburg, 2020-11) Madonsela, Thando Kwenza; Sihlongonyane, MfaniseniHostels in the South Africa context are synonymous with the migrant labour system. The dominant feature of these pre-democratic hostels is that they catered for single-sex employees as opposed to worker families. This contributed to the destruction of the social fabric in terms of culture, traditions, and the destruction of the black families at large. In post-democratic South Africa, Hostel accommodation continues to paint a grim picture within our human settlement’s spaces. Socio-economic difficulties manifest themselves in mostly inadequate living conditions or poor housing circumstances that are largely conditioned by the unequal and distorted access to opportunities. To this day, most hostels that are not yet redeveloped or refurbished continue to present images of dirty menacing buildings associated with a public stigma of notoriety. This research study explores socio-economic perspectives in the redevelopment of hostels in South Africa. The study will consist of an interface between theoretical foundations, and empirical evidence. This research, data collection was sourced both from primary and secondary sources. Qualitative investigative methods were used to get an in-depth understanding of the subject. The research follows a case-study approach, that of Wolhuter Hostel, Jeppestown in Gauteng and undertook interviews of sixteen hostel dwellers plus a fucus group discussion. The study makes recommendations on policy reforms such introducing more responsive programmes in human settlements. It is also aimed at introducing an improved approach to the planning and redevelopment of the hostels by strengthening neighbourhood and precinct planning. The study contributes to the understanding and insight on hostels and their redevelopment and considering socio-economic perspectives in human settlements planning and development.