School of Animal, Plant and Environmental Sciences (ETDs)

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Browsing School of Animal, Plant and Environmental Sciences (ETDs) by SDG "SDG-8: Decent work and economic growth"

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    Evaluation of the JSE’s environmental reporting requirements of South African listed companies
    (University of the Witwatersrand, Johannesburg, 2024) Hariram, Viratha; Schwaibold, Ute
    Through its mandatory environmental reporting requirements, the Johannesburg Stock Exchange (JSE) plays a pivotal role in the private sector to align to Environmental, Social and Governance frameworks and disclose information of a company’s environmental priorities and performance in addressing areas of concern. While there are attempts to safeguard the environment from damage and degradation, it is unclear if this framework is suitable at appropriately addressing the environmental areas of concern facing South Africa. In order to evaluate the JSE’s environmental requirements on listed companies, this study aimed to identify the local and global environmental priorities via the South African State of Environment Outlook Report (local view), National Development Plan (local view) and Sustainable Development Goals (global view) and thereafter determine if the Global Reporting Initiative, the only set of mandatory environmental requirements of the JSE, was adequately addressing the indicators they outlined. Furthermore, using a scoring system from zero to four, the study evaluated the alignment of ten randomly selected JSE listed companies against the requirements of the Global Reporting Initiative to note their level of adherence and alignment to the South African State of Environment Outlook Report, National Development Plan and Sustainable Development Goals. The results indicate that the Global Reporting Initiative (GRI) covers 73% of environmental priorities discussed in the South African State of Environment Outlook Report, National Development Plan and Sustainable Development Goals. Of the total 74 indicators of environmental concern identified from the three reports, the GRI did not require disclosure for 20 indicators. Only three indicators that were required to be disclosed by the GRI had scored a four on the rating scale due to it being an integrated disclosure that takes into account one or more other related environmental categories. The evaluation of the sampled listed company’s adherence to the GRI via their sustainability reports and integrated annual reports indicated that none of the companies had provided sufficient disclosures to meet the requirements of the GRI. 80% of the sampled listed companies made a strong alignment to the Sustainable Development Goals in their sustainability reports and / or integrated annual reports. A shortcoming of the JSE that was stated by all four sustainability experts interviewed was the lack of enforcement for listed companies to make quality and comprehensive disclosures or accountability expected from listed companies. There is no formal process of review or consequences for listed companies who do not comply.
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    The impact of fly ash on the growth rate of maize (Zea mays L.) and the potential for fly ash to be used commercially in agriculture
    (University of the Witwatersrand, Johannesburg, 2022) Riba, Mpho Mahlatse; Scholes, Mary
    South Africa’s coal-fired power plants (CFPPs) produce about 34.4 million tons of fly ash (FA) per annum, as a by-product of the coal combustion process, which is stockpiled adjacent to these CFPPs. This FA contains traces of heavy metals (HMs), as a result it is a potential environmental hazard. The purpose of this study was, therefore, to establish the effects of (‘FA’) on the growth of maize (Zea mays L.), as well as its potential commercial use in agriculture due to its nutrient content, instead of maintaining the status quo. Another aim of the study was also to determine the phytoextraction abilities of the HMs (Mn, Cr, Ba and Mo) from contaminated soils by the maize plants. The study was conducted by planting maize seeds in five soil substrates with 0 %, 20 %, 40 %, 55 % and 60 % FA treatment, on mass basis. The ANOVA indicated that there were significant differences when comparing most of the mean stem length, number of leaves, root length and the mean mass of total plant dry biomass, across all the FA treatments, after 122 days of growth. The mean stem lengths after 122 days of growth were 86.67  20.55 cm, 148.33  13.87 cm, 154.17  18.10 cm, 121.17  14.99 cm and 149.50  24.20 cm for maize plants grown in 0 % , 20 %, 40 %, 55 % and 60 % FA treatments, respectively. The mean number of leaves were 12  1.87, 16  2.34, 18  2.83, 12  1.87 and 14  1.79 across all treatments, respectively. The key finding was that the growth of these plants improved with the amount of FA in the soil, with the plants that were grown in the 40 % FA treatment yielding the best results. The same observation was made with the root length and the mean masses of total plant biomass (roots, stems and leaves). Another important finding was that the accumulation of the HMs (Mn and Cr) in the plants increased, across the FA treatments, while their concentrations in the soil decreased across the FA treatments. The accumulation of Ba and Mo in the plants also increased, across the FA treatments, while Ba remained slightly constant and Mo increased in the soil. This indicated that the maize plants can potentially remediate Mn and Cr contaminated soils, through phytoextration, but are retained in the root system.
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    The reporting of the sustainability goals and the Sustainable Development Goals (SDGs) in the context of the private sector in South Africa
    (University of the Witwatersrand, Johannesburg, 2022) Mosi, Tumelo
    Sustainability challenges continue to mount and the fate of this planet lies in a precarious position. In response, the United Nations has introduced a global agreement known as the Sustainable Development Goals (SDGs). These are 17 goals underpinned by 169 targets for addressing social, economic and environmental issues on a global scale. The SDGs seek to do so by unlocking the potential that lies within the private sector and more. The aim of my research was to assess the sustainability goals disclosed by the top 25 Johannesburg Stock Exchange (JSE) listed companies against that of five other countries in 2017. Furthermore, I compared the environmental SDG disclosure of five companies from the metals and mining sector as well as the consumer products sector respectively, within the same period. The sample was selected from the original sample of the top 25 JSE listed companies. Comparisons were done by analysing sustainability/annual/integrated reports of the top 25 JSE listed companies. The results for the sample showed South Africa to be lagging behind the other countries with regards to disclosing sustainability goals in the corporate sustainability reporting for 2017. From 2017 to 2019, the number of reports addressing environmental SDGs from the selected sectors showed an increase. Furthermore, the study companies from the metal and mining sector performed better than those from the consumer products sector with regards to environmental SDG disclosure. However, the environmental SDG score of the study companies from the consumer products sector increased relatively more within the three years of assessment (2017-2019). Variation was also found between the study companies from the two sectors with regards to preference for specific environmental SDGs which included Responsible Consumption and Production (SDG 12), Climate Action (SDG 13), Life Below Water (SDG 14) and Life on Land (SDG 15). Moreover, the iii interviews conducted with the relevant participants revealed that SDG awareness has improved overtime, however internalisation of the SDGs remains the biggest challenge.
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    Water Quality Monitoring of Biological and Chemical Pollutants into the Wakkerstroom Wetland
    (University of the Witwatersrand, Johannesburg, 2024) Klinkert, Celine; Scholes, Mary
    Wetlands are among the most important ecosystems in the world due to the array of ecosystem services that they provide, such as flood attenuation, ground water restoration, water filtration and pollutant removal, climate change regulation and reducing erosion. The Wakkerstroom wetland in the Mpumalanga Province South Africa, plays a major role in improving downstream water quality. The wetland is threatened due to excess nutrient loading and microbiological contaminants entering the water column from a sewage ground runoff and a malfunctioning wastewater treatment plant. This study aims to determine the water quality and nutrient removal from the wetland by assessing chemical parameters and coliform and E.coli contamination as faecal indicators. Eight sampling sites were chosen along the length of the wetland, and water sample collection occurred once a month between August 2021 and July 2022. The results showed a neutral pH between 6 and 8 with no spatial or temporal significant differences. The mean Total Dissolved Solids (TDS) ranged between 50 – 145 mg/L. The mean nitrate concentrations (NO3-) ranged between 1.50 and 7.00 mg/L across the sampling sites. During the sampling period, a net total of 17.53 mg/L of nitrate was removed from the water column by the wetland. The mean phosphate concentration (PO43-) ranged between 0.40 – 1.40 mg/L, showing a total net removal of 2.14 mg/L during the sampling period. Coliform abundance was high closest to the wastewater treatment plant and sewage runoff and decreased along the length of the wetland, with an estimate removal of 1.17, calculated from a qualitative colour changing scoring system. E.coli bacteria was present in the wetland at all of the sampling sites between March 2022 to July 2022. This study resulted in the confirmation of a healthy, functioning wetland system where the wetland is able to reduce excess nutrients and coliform contamination. The wetland water quality shows similarities to studies conducted on wetlands in South Africa. The wetland is still under threat through possible reduced functioning as a result of excessive exposure to untreated domestic and sewage waste. A need exists for improved management and more stringent standards of water quality control from the wastewater treatment plant to reduce the risk of wetland degradation through excessive sewage exposure.