Magister Scientiae - MSc (Environ & Water Science)

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https://hdl.handle.net/10566/17575

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Browsing by Author "Clarke, Sumaya"

Now showing 1 - 7 of 7
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    Assessing effectiveness of groundwater remediation technologies to a coastal aquifer within an urban environment in South Africa
    (University of the Western Cape, 2022) Kanyerere, Jessie Mzati; Clarke, Sumaya
    The study aimed to assess the effectiveness of Reverse Osmosis technology as an example of ex-situ groundwater remediation technologies. The Cape Flats Aquifer System, an urban coastal system, was used as a case study. Globally, urban groundwater contamination remains a known problem for water users, hence the need to remediate such water. The study argues that effective technologies such as Reverse Osmosis to remediate groundwater contaminants exist. However, the effectiveness of such technologies is not demonstrated to inform the wider application. The question of how effective these technologies are in remediating groundwater contaminants is not fully understood.
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    An assessment of factors influencing the spatial variability of iron concentrations in groundwater in selected areas of the Western Cape Province.
    (University of the Western Cape, 2023) Bissonram, Presanta; Clarke, Sumaya
    Groundwater in South Africa, and more specifically the Western Cape Province (WCP), has become of major interest in recent years due to the unpredictable climatic conditions and the uncertainty of surface water to continuously meet the current and future water demands. With the exploration of groundwater (through the drilling of boreholes) to meet the current water demand and to ensure water security there comes the related problem of iron (Fe) and Manganese (Mn) oxidation and precipitation. The precipitation of Fe and Mn in boreholes reduce the yield and quality of the water, resulting in borehole clogging. This study took place in the WCP and the sites sampled at were hospitals as part of the business continuity project that was initiated during the drought in that took place in Cape Town in 2017. There are 4 objectives for this study which are to assess spatial variations in Fe and Mn concentrations, to establish site-specific processes controlling the concentration of Fe and Mn in groundwater, to model the likelihood of precipitation of Fe and Mn based on detected solution composition and to assess the best practice method/techniques for sampling Fe and Mn. This research project made use of quantitative and qualitative research methods. The first two objectives was addressed by using historical data which included groundwater chemistry data, pumping test data and geological data of the WCP. In addition to the historical data being used sampling was done at selected sites to understand the current groundwater chemistry, while interviews were conducted with site maintenance personnel to further understand the management of the boreholes. The third objective made use of the PHREEQC software to determine the saturation indices of samples collected and modelling of the effect of change in Fe, Mn, redox potential, pH and temperature has on the precipitation of Fe and Mn minerals. The last objective was achieved through the sampling conducted which provided the opportunity to test the best practice sampling methods of Fe and Mn in groundwater.
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    Effects of acid concentration on the extraction of rare earth elements from South African Coal Fly Ash
    (University of Western Cape, 2021) Mokoena, Kamohelo; Clarke, Sumaya
    Coal is seen as a reliable and secure energy source in many countries around the world despite the development of a number of alternative sources of energy. A rise in global energy demand has led to an increase in coal consumption. Consequently, global coal fly ash (CFA) production has increased creating a pressing need for recycling and utilisation of coal fly ash. South Africa produces 50 million tons of ash per year from coal combustion with only about 10 % being utilised. There has been a rise in demand for REEs over the past decades due to their use in optics, automotive, electronics, energy, defence industries etc. These precious elements are known to be contained in CFA, making it a potential source.
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    The fate and occurrence of pharmaceuticals in Cape Town’s water network
    (University of the Western Cape, 2022) Cloete, Mikyle; Clarke, Sumaya
    Thousands of pharmaceuticals, pesticides and microplastics are consumed and disposed of directly or indirectly into various water bodies globally. Which are collectively termed “contaminants of emerging concern” or CECs. Contaminants of emerging concerns are defined as micropollutants that are present in the environment that are not regulated and that can pose a risk to the health of both humans and wildlife. The distribution of these CECs in water systems is not isolated to a specific place and is on the rise all over the world. This study aims to investigate the spatial and temporal distribution of pharmaceuticals in the environment regarding the change in concentration along a flow path from potential sources to sink, to assess the occurrence, concentration levels and distribution of pharmaceuticals in various water bodies.
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    A lab based experimental study of a bioretention system to remove selected pharmaceuticals in stormwater
    (University of the Western Cape, 2023) Maphiri, Refiloe; Clarke, Sumaya
    The use of treated stormwater as an alternative source of water supply in urban areas is receiving global recognition. This approach is being supported as an innovative initiative that improves urban water security and diversifies urban water demand management options. However, reported toxic pollutants from some land-use activities threaten the quality of stormwater thereby restricting the potential for using stormwater to augment the water supply system. Such reported risks entail the treatment of the stormwater before its use for any purpose. Therefore, this study reports the findings of the research which investigated the effectiveness of a bioretention system in removing pharmaceuticals from stormwater and the influence of retention time and stormwater volumes on the removal efficiency of the pharmaceuticals by the bioretention system. To achieve the objectives of the study, there was a need to identify and measure the concentration levels of the pharmaceuticals found in stormwater. It was also necessary to determine the removal efficiency of the identified pharmaceuticals by using the Turf Grass and Pennisetum plants in a bioretention system with soil media control.
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    The presence and concentration of antiretroviral drugs in different water bodies around the Western Cape
    (University of the Western Cape, 2023) Maphumulo, Phumelele; Clarke, Sumaya
    Concerns regarding the prevalence of chemicals from medicines and personal care goods, such as cosmetics, in streams and rivers have grown in recent years. Water quality experts and environmentalists are becoming increasingly worried about contaminants found in prescription and over-the-counter pharmaceuticals that enter various water systems. Pharmaceuticals are significant contributors to water pollution in aquatic habitats such as surface and groundwater. These contaminants are produced not only by waste materials, but also by improperly disposed of pharmaceutical items. South Africa has the world's highest rate of HIV (Human immunodeficiency virus infection) and AIDS (Acquired immune deficiency syndrome), with 8.2 million South Africans infected with HIV/AIDS, and 68% are receiving antiretroviral therapy. These medications get deposited in the environment and might reach water bodies, contaminating them.
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    Using stable isotopes and hydrochemistry to quantify end-member source dynamics in the Berg River of the Franschhoek and Paarl Valley
    (University of the Western Cape, 2023) Meyer, Celine; Clarke, Sumaya
    The Berg River is a main source of freshwater in South Africa's Franschhoek-Paarl valley for domestic use, industry, and agriculture, but climate change or variability and poor management threaten its quality and quantity. A theoretical understanding of the basin's runoff processes, including the balance between groundwater and precipitation inputs in the river system, is crucial for meeting ecological reserve requirements and preserving ecosystems. By comprehending the dynamics and relationship between the river and its end-member sources by evaluating the contributions of groundwater and precipitation to the streamflow and the seasonal behaviour of solutes, the ecological health and functioning of the river and its associated ecosystems can successfully be managed and maintained. This study involved 25 sampling campaigns conducted between 2020 and 2021 along the Berg River in the Franschhoek and Paarl valley at 40 locations to sample precipitation (n=3), groundwater (n=15), and main river and major tributaries (n=22). The aim was to assess the temporal and spatial variations of the isotopic and hydrochemical compositions to quantify the river’s end-member source dynamics.