Photodynamic anticancer and antimicrobial activities of novel bacteriochlorins
- Tauyakhale, Kaisano Goodness
- Authors: Tauyakhale, Kaisano Goodness
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464587 , vital:76524
- Description: The World Health Organization cautioned that the major contributing factors of cancer amongst people are the excessive usage of alcohol, smoking, lack of exercise and low intake of fruits, vegetables, and high-fibre foods. Furthermore, cancer by far is reported to be the most common and leading cause of death worldwide (1 in 6 deaths is due to cancer). Moreover, it is reported that cancer kills more people than tuberculosis, malaria and AIDS combined every year. Chemotherapy has been utilised as a mode of rehabilitation for complete being used in conjunction with surgery or to improve the state of well-being of patients until their point of death. However, it is well known for its adverse effects, such as loss of hair, altered gastric metabolism, vomiting and nausea, dehydration, weight loss, and loss of appetite. For this reason, photodynamic therapy (PDT) was developed as an alternative. A molecular dye (photosensitiser/PS) and light of a specific wavelength produce cytotoxic singlet oxygen species, which induce cell death. The aim of this project is to prepare novel structurally modified porphyrin-type dyes that absorb far into the near-infrared region. Identifying suitable dyes that absorb significantly in the 700−800 nm region is particularly important from an African perspective, since melanin significantly limits the penetration of laser light into human tissue in the 600−700 nm region, where first- and second-generation photosensitiser dyes usually absorb. The porphyrin analogues that will be investigated in this regard are bacteriochlorins (BChls), which are known to have suitable optical properties that are potentially suitable in this regard. The first step of the study would be to synthesise tetraarylporphyrins with electron- withdrawing meso-aryl rings because their reduction to BChls is more readily attainable than is the case with electron-donating rings. However, these contrasting properties can be combined to tailor the BChls for effective photodynamic therapy, so the type of porphyrins synthesised will be tetraarylBChls with different meso-aryl groups to first analyze the induction of different chemical properties in this case, the impact of introducing electron donating (4- and 3-quinoline substituents) or electron-withdrawing (pentafluorophenyl substituents) groups on the meso-positions of the dyes and more specifically whether the position of the quinoline nitrogen atom relative to the core of the BChl has any significant impact on the reactivity of the dye (the 4- or 3-position of the quinoline). The next factor to be considered is the induction of the heavy atom effect by introducing a metal in the centre of the dye in order to try to increase the singlet oxygen quantum yields for high production of reactive oxygen species and singlet oxygen and further red shift the lowest energy absorption band of the BChls in the therapeutic window for deep tissue penetration for effective. Lastly, the goal will be to explore whether the delivery of bacteriochlorin photosensitisers to cancer cells can be enhanced by introducing quaternised nitrogen atoms to the meso-aryl ligands. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
- Authors: Tauyakhale, Kaisano Goodness
- Date: 2024-10-11
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/464587 , vital:76524
- Description: The World Health Organization cautioned that the major contributing factors of cancer amongst people are the excessive usage of alcohol, smoking, lack of exercise and low intake of fruits, vegetables, and high-fibre foods. Furthermore, cancer by far is reported to be the most common and leading cause of death worldwide (1 in 6 deaths is due to cancer). Moreover, it is reported that cancer kills more people than tuberculosis, malaria and AIDS combined every year. Chemotherapy has been utilised as a mode of rehabilitation for complete being used in conjunction with surgery or to improve the state of well-being of patients until their point of death. However, it is well known for its adverse effects, such as loss of hair, altered gastric metabolism, vomiting and nausea, dehydration, weight loss, and loss of appetite. For this reason, photodynamic therapy (PDT) was developed as an alternative. A molecular dye (photosensitiser/PS) and light of a specific wavelength produce cytotoxic singlet oxygen species, which induce cell death. The aim of this project is to prepare novel structurally modified porphyrin-type dyes that absorb far into the near-infrared region. Identifying suitable dyes that absorb significantly in the 700−800 nm region is particularly important from an African perspective, since melanin significantly limits the penetration of laser light into human tissue in the 600−700 nm region, where first- and second-generation photosensitiser dyes usually absorb. The porphyrin analogues that will be investigated in this regard are bacteriochlorins (BChls), which are known to have suitable optical properties that are potentially suitable in this regard. The first step of the study would be to synthesise tetraarylporphyrins with electron- withdrawing meso-aryl rings because their reduction to BChls is more readily attainable than is the case with electron-donating rings. However, these contrasting properties can be combined to tailor the BChls for effective photodynamic therapy, so the type of porphyrins synthesised will be tetraarylBChls with different meso-aryl groups to first analyze the induction of different chemical properties in this case, the impact of introducing electron donating (4- and 3-quinoline substituents) or electron-withdrawing (pentafluorophenyl substituents) groups on the meso-positions of the dyes and more specifically whether the position of the quinoline nitrogen atom relative to the core of the BChl has any significant impact on the reactivity of the dye (the 4- or 3-position of the quinoline). The next factor to be considered is the induction of the heavy atom effect by introducing a metal in the centre of the dye in order to try to increase the singlet oxygen quantum yields for high production of reactive oxygen species and singlet oxygen and further red shift the lowest energy absorption band of the BChls in the therapeutic window for deep tissue penetration for effective. Lastly, the goal will be to explore whether the delivery of bacteriochlorin photosensitisers to cancer cells can be enhanced by introducing quaternised nitrogen atoms to the meso-aryl ligands. , Thesis (MSc) -- Faculty of Science, Chemistry, 2024
- Full Text:
- Date Issued: 2024-10-11
The influence of strategic leadership on the performance of small and medium-sized enterprises as mediated by strategy implementation
- Authors: January, Nceba
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434723 , vital:73099
- Description: Small and medium-sized enterprises (SMEs) are viewed as the cornerstone of socio-economic development in many economies globally. The progressive contribution of SMEs to the global economy is irrefutable and enshrined in poverty alleviation, inclusive economic growth, and job creation strategies pursued by many economies worldwide. SMEs are primarily the form of enterprise that accounts for over 90% of all businesses; thus, Small and Medium-sized Enterprises are the main source of employment. SMEs' contribution to value creation is estimated to be above 50% on average. In emerging countries, particularly South Africa, SMEs contribute approximately 45% of the total employment and 33% of the Gross Domestic Product (GDP). In most countries, Small and Medium-sized Enterprises contribute to more than 50% of employment and GDP, and these figures become significantly higher when the informal small business sector is included. World Bank estimated 600 million jobs needed by 2030, making SME development a high priority for many governments worldwide. Despite globally acknowledged SME contributions, small businesses are still faced with many challenges that have ramifications on their survival, growth, and performance. Studies highlighted challenges such as lack of access to finance and funding modalities, appropriate technology and infrastructure, markets and social networks, and lack of research and development, strategic management skills, and inability to perform managerial tasks, among others. Recent studies have been conducted on many of these challenges; however, there is little known about the strategic management challenges that face SMEs and their business performance. Several studies were conducted on some of these strategic management challenges, such as strategic planning, strategic orientation, strategic agility, organisational flexibility, and total quality management. However, a review of studies relevant to SMEs and their performance is silent on the argument regarding the influence of strategic leadership on the performance of SMEs, especially when key drivers of effective strategy implementation mediate strategic leadership. Thus, this study investigated the influence of strategic leadership on the performance of SMEs as mediated by strategy implementation in Nelson Mandela Bay (NMB). A detailed theoretical investigation was conducted on the nature and role of strategic leadership, strategy implementation, and business performance of SMEs. Strategic leadership represents the independent variables of this study, namely: strategic direction, balanced organisational controls, organisational culture, organisation’s resource portfolio, and ethical practice, followed by the mediating variable (strategy implementation) and the dependent variable (business performance). An empirical investigation was also conducted to test the significant influence between these variables. This study adopted a positivistic approach using a quantitative research method. The sample size of the study was 390 respondents. Self-developed and structured questionnaires were physically distributed to 315 SME owners and managers in NMB using a convenience sampling method. Only 229 returned questionnaires were suitable and relevant to this study; thus, a 72.69% response rate was achieved. Returned questionnaires were cleansed, coded, and transferred to a statistical data analysis software called Statistica, version 14.0, for quantitative data analyses. The validity and reliability of the measuring instrument were confirmed using Exploratory Factor Analysis and the calculation of Cronbach’s alpha coefficients. Descriptive statistics was calculated to summarise the empirical data on demographic variables and the main variables of this study. Pearson’s correlations were calculated to determine the correlations between the main variables of this study, and the results confirmed that there is a positive influence between strategic leadership, strategy implementation, and business performance of SMEs. A multiple linear regression analysis was conducted to test the significance of the influence between the main variables of the study. A regression analysis outcome revealed that some of the strategic leadership activities (strategic direction, balanced organisational controls, and organisational culture) have a statistically significant positive influence on the business performance of SMEs. Furthermore, a statistically significant positive influence does exist between strategy implementation and business performance of SMEs. This study’s recommendations were suggested to SME owners/managers. Firstly, to formulate and develop a clear long-term vision of the business for the next 3 to 5 years. Align resources to key areas of business operation and set internal controls that will help set standards of desired performance and ultimately achieve them. Secondly, to formulate and implement shared values that connect employees to the business purpose and the way it is conducted. These shared values must be underpinned by a unique, valuable, and incomparable culture against competitors to gain a competitive edge. Furthermore, consider using rewards to recognise employees who embody the shared values of the business and are committed to the success of the business because of its culture. Thirdly, ensure both strategic and financial controls support strategy implementation and guide employees to achieve performance objectives. Use balanced scorecards to assess the effectiveness of controls in the business and put corrective measures to address performance gaps. Last but not least, invest in staff development and training, technological infrastructure, and set sound processes and systems for the business operation, establish structures that have clear lines of reporting, authority, and delegation. , Thesis (MCom) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
- Authors: January, Nceba
- Date: 2024-04-03
- Subjects: Uncatalogued
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/434723 , vital:73099
- Description: Small and medium-sized enterprises (SMEs) are viewed as the cornerstone of socio-economic development in many economies globally. The progressive contribution of SMEs to the global economy is irrefutable and enshrined in poverty alleviation, inclusive economic growth, and job creation strategies pursued by many economies worldwide. SMEs are primarily the form of enterprise that accounts for over 90% of all businesses; thus, Small and Medium-sized Enterprises are the main source of employment. SMEs' contribution to value creation is estimated to be above 50% on average. In emerging countries, particularly South Africa, SMEs contribute approximately 45% of the total employment and 33% of the Gross Domestic Product (GDP). In most countries, Small and Medium-sized Enterprises contribute to more than 50% of employment and GDP, and these figures become significantly higher when the informal small business sector is included. World Bank estimated 600 million jobs needed by 2030, making SME development a high priority for many governments worldwide. Despite globally acknowledged SME contributions, small businesses are still faced with many challenges that have ramifications on their survival, growth, and performance. Studies highlighted challenges such as lack of access to finance and funding modalities, appropriate technology and infrastructure, markets and social networks, and lack of research and development, strategic management skills, and inability to perform managerial tasks, among others. Recent studies have been conducted on many of these challenges; however, there is little known about the strategic management challenges that face SMEs and their business performance. Several studies were conducted on some of these strategic management challenges, such as strategic planning, strategic orientation, strategic agility, organisational flexibility, and total quality management. However, a review of studies relevant to SMEs and their performance is silent on the argument regarding the influence of strategic leadership on the performance of SMEs, especially when key drivers of effective strategy implementation mediate strategic leadership. Thus, this study investigated the influence of strategic leadership on the performance of SMEs as mediated by strategy implementation in Nelson Mandela Bay (NMB). A detailed theoretical investigation was conducted on the nature and role of strategic leadership, strategy implementation, and business performance of SMEs. Strategic leadership represents the independent variables of this study, namely: strategic direction, balanced organisational controls, organisational culture, organisation’s resource portfolio, and ethical practice, followed by the mediating variable (strategy implementation) and the dependent variable (business performance). An empirical investigation was also conducted to test the significant influence between these variables. This study adopted a positivistic approach using a quantitative research method. The sample size of the study was 390 respondents. Self-developed and structured questionnaires were physically distributed to 315 SME owners and managers in NMB using a convenience sampling method. Only 229 returned questionnaires were suitable and relevant to this study; thus, a 72.69% response rate was achieved. Returned questionnaires were cleansed, coded, and transferred to a statistical data analysis software called Statistica, version 14.0, for quantitative data analyses. The validity and reliability of the measuring instrument were confirmed using Exploratory Factor Analysis and the calculation of Cronbach’s alpha coefficients. Descriptive statistics was calculated to summarise the empirical data on demographic variables and the main variables of this study. Pearson’s correlations were calculated to determine the correlations between the main variables of this study, and the results confirmed that there is a positive influence between strategic leadership, strategy implementation, and business performance of SMEs. A multiple linear regression analysis was conducted to test the significance of the influence between the main variables of the study. A regression analysis outcome revealed that some of the strategic leadership activities (strategic direction, balanced organisational controls, and organisational culture) have a statistically significant positive influence on the business performance of SMEs. Furthermore, a statistically significant positive influence does exist between strategy implementation and business performance of SMEs. This study’s recommendations were suggested to SME owners/managers. Firstly, to formulate and develop a clear long-term vision of the business for the next 3 to 5 years. Align resources to key areas of business operation and set internal controls that will help set standards of desired performance and ultimately achieve them. Secondly, to formulate and implement shared values that connect employees to the business purpose and the way it is conducted. These shared values must be underpinned by a unique, valuable, and incomparable culture against competitors to gain a competitive edge. Furthermore, consider using rewards to recognise employees who embody the shared values of the business and are committed to the success of the business because of its culture. Thirdly, ensure both strategic and financial controls support strategy implementation and guide employees to achieve performance objectives. Use balanced scorecards to assess the effectiveness of controls in the business and put corrective measures to address performance gaps. Last but not least, invest in staff development and training, technological infrastructure, and set sound processes and systems for the business operation, establish structures that have clear lines of reporting, authority, and delegation. , Thesis (MCom) -- Faculty of Commerce, Management, 2024
- Full Text:
- Date Issued: 2024-04-03
Exploring how Grade 11 Chemistry teachers mediate learning of the topic redox reactions in their classrooms in Namibia
- Iindombo, Junilla Inamudhimbwa
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Chemistry Study and teaching (Secondary) Namibia , Pedagogical content knowledge , Oxidation Study and teaching (Secondary) Namibia , Oxidation-reduction reaction Study and teaching (Secondary) Activity programs Namibia , Practical work
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Iindombo, Junilla Inamudhimbwa
- Date: 2023-10-13
- Subjects: Chemistry Study and teaching (Secondary) Namibia , Pedagogical content knowledge , Oxidation Study and teaching (Secondary) Namibia , Oxidation-reduction reaction Study and teaching (Secondary) Activity programs Namibia , Practical work
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/424030 , vital:72117
- Description: The Namibian Chemistry ordinary level syllabus requires learners to study the topic of redox reactions. This topic has proven to be one of the most difficult for Namibian learners as reflected by their poor responses to questions in the Grade 11 and 12 Namibian Senior Secondary Certificate ‘O’ examinations. Teaching abstract concepts such as redox reactions requires higher cognitive thinking skills and thus presents a challenge. Against this background, this study sought to explore how teachers mediate learning of redox reactions in their classrooms. The focus was on conceptual understanding through linking content to the context of the learners. The study was underpinned by an interpretivist paradigm, within which a qualitative case study approach was adopted. Two Grade 11 Chemistry teachers from the Ohangwena and Oshana regions in Namibia were the research participants. I used semi-structured interviews, lesson observations and stimulated recall interviews to collect data. I used Shulman’s Pedagogical Content Knowledge as a theoretical framework in this study and the data sets were analysed using the Topic-Specific Pedagogical Content Knowledge components. Qualitative data were analysed inductively-deductively. The study’s findings revealed that teachers used various mediation tools such as analogies and prior knowledge. The results further illuminated that teachers should develop strong subject content knowledge and pedagogical content knowledge to have the best strategies in place to mediate learning of this topic. , Thesis (MEd) -- Faculty of Education, Secondary and Post-School Education, 2023
- Full Text:
- Date Issued: 2023-10-13
Social Learning and Regenerative Sustainability: Unlocking value created in sustainability projects in higher education
- Authors: Royle, Carlene
- Date: 2023-10-13
- Subjects: Social Learning South Africa Makhanda , Sustainability South Africa Makhanda , Education, Higher Social aspects South Africa Makhanda , Social accounting South Africa Makhanda , Education, Higher Activity programs South Africa Makhanda , Value creation , Agent (Philosophy) , Sustainable Development Goals
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/402981 , vital:69911
- Description: This qualitative study considers two bodies of theory, regenerative sustainability and social learning theory, within a tertiary education context. Universities offer unique opportunities, across both the formal and informal curriculum, that engage with the two-fold socioeconomic and environmental crises. The study explores both the promise of unlocking value in an ex-linear economy; and the healing and regenerative benefits in moving toward greener practices. Through an embedded case study at Rhodes University, in the Eastern Cape of South Africa, this research explores the value that is being unlocked in campus-based sustainability projects, when considered through a social learning lens (Lave and Wenger, 1991). Invitations to participate in this study were extended to project-leads of sustainability initiatives originating from Rhodes University campus. Six projects, which have been active on campus in recent years, were selected and, through semi-structured interviews, the insights of 12 participants were captured and analysed using the associated Value Creation Framework (VCF) developed by Wenger, Trayner and De Laat (Wenger, Trayner, de Laat, 2011) and later Wenger-Trayner and Wenger Trayner (2014, 2015, 2020). The VCF consists of value cycles that interconnect dynamically, including Orientating, Strategic, Enabling, Immediate, Potential, Applied, Realised and Reframed or Transformative value cycles. The study identified instances of all these value cycles, within and across the six embedded case studies (project). Drawing on social learning theorists the analysis further focused on instances of collaboration, agency and boundary crossing. Additional themes that emerged across the majority of the embedded study projects, were a convergence of socio and eco; a whole-systems perspective shared by project leads; the importance of the social commons; language as an enabler; and problem solving for system change. A recommendation is proposed to further unlock the unbounded value created through such projects by reframing the informal curriculum opportunities offered on university campuses as social learning spaces where students can practice agency. To do so, would require formalizing various forms of system support, thus facilitating expanded learning in regenerative sustainability activities, for the common social and planetary good. , Thesis (MEd) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-10-13
- Authors: Royle, Carlene
- Date: 2023-10-13
- Subjects: Social Learning South Africa Makhanda , Sustainability South Africa Makhanda , Education, Higher Social aspects South Africa Makhanda , Social accounting South Africa Makhanda , Education, Higher Activity programs South Africa Makhanda , Value creation , Agent (Philosophy) , Sustainable Development Goals
- Language: English
- Type: Academic theses , Master's theses , text
- Identifier: http://hdl.handle.net/10962/402981 , vital:69911
- Description: This qualitative study considers two bodies of theory, regenerative sustainability and social learning theory, within a tertiary education context. Universities offer unique opportunities, across both the formal and informal curriculum, that engage with the two-fold socioeconomic and environmental crises. The study explores both the promise of unlocking value in an ex-linear economy; and the healing and regenerative benefits in moving toward greener practices. Through an embedded case study at Rhodes University, in the Eastern Cape of South Africa, this research explores the value that is being unlocked in campus-based sustainability projects, when considered through a social learning lens (Lave and Wenger, 1991). Invitations to participate in this study were extended to project-leads of sustainability initiatives originating from Rhodes University campus. Six projects, which have been active on campus in recent years, were selected and, through semi-structured interviews, the insights of 12 participants were captured and analysed using the associated Value Creation Framework (VCF) developed by Wenger, Trayner and De Laat (Wenger, Trayner, de Laat, 2011) and later Wenger-Trayner and Wenger Trayner (2014, 2015, 2020). The VCF consists of value cycles that interconnect dynamically, including Orientating, Strategic, Enabling, Immediate, Potential, Applied, Realised and Reframed or Transformative value cycles. The study identified instances of all these value cycles, within and across the six embedded case studies (project). Drawing on social learning theorists the analysis further focused on instances of collaboration, agency and boundary crossing. Additional themes that emerged across the majority of the embedded study projects, were a convergence of socio and eco; a whole-systems perspective shared by project leads; the importance of the social commons; language as an enabler; and problem solving for system change. A recommendation is proposed to further unlock the unbounded value created through such projects by reframing the informal curriculum opportunities offered on university campuses as social learning spaces where students can practice agency. To do so, would require formalizing various forms of system support, thus facilitating expanded learning in regenerative sustainability activities, for the common social and planetary good. , Thesis (MEd) -- Faculty of Education, Education, 2023
- Full Text:
- Date Issued: 2023-10-13
The protection and promotion of the rights of journalists in Tanzania.
- Authors: Nnko, Ruth Anaeli
- Date: 2022-12
- Subjects: freedom of speech , Journalism , Human rights
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60100 , vital:63095
- Description: The ability to freely acquire, search for, disseminate, and express opinions and ideas is foundational in a democratic society. When a state effectively safeguards the right to freedom of expression of all citizens, this has a rollover effect on other fundamental human rights. Freedom of expression often operates in tandem with the right to information, equality and human dignity. To this effect, freedom of expression has been recognized as a fundamental human right in various international, regional and sub-regional instruments. The scope and limitations of the right to freedom of expression has, over the years, been developed through regional and sub-regional cases. These cases have noted that, on the one hand, freedom of expression goes beyond a mere aspiration of states. State Parties to human rights’ instruments are bound by an obligation to give effect to this right. On the other hand, however, freedom of expression is not absolute and can be limited where such limitation is necessary, lawful, and proportional. Within the United Republic of Tanzania, techniques have been adopted to limit the right to freedom of expression of journalists. These range from the use of national laws to fines, suspensions, and imprisoning of journalists, to extrajudicial acts such as enforced disappearances in more extreme cases. Although, these techniques are not unique to the United Republic of Tanzania as the same ill treatment of journalists’ practices can be found in other countries. This study evaluates whether the legal framework, as well as the actions of the United Republic of Tanzania, in effect, protect and promote the right to freedom of expression specifically the rights of journalists. This study is divided in five chapters which aim to provide an in-depth coverage of the human rights systems in operation that are apply to journalists in Tanzania. The study also considers limitations in the regional, subregional and national legal frameworks and concludes with recommendations that could be adopted to ensure compliance with sub-regional, regional and international standards. , Thesis (LLM) -- Faculty Law, Criminal and Procedural Law, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Nnko, Ruth Anaeli
- Date: 2022-12
- Subjects: freedom of speech , Journalism , Human rights
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60100 , vital:63095
- Description: The ability to freely acquire, search for, disseminate, and express opinions and ideas is foundational in a democratic society. When a state effectively safeguards the right to freedom of expression of all citizens, this has a rollover effect on other fundamental human rights. Freedom of expression often operates in tandem with the right to information, equality and human dignity. To this effect, freedom of expression has been recognized as a fundamental human right in various international, regional and sub-regional instruments. The scope and limitations of the right to freedom of expression has, over the years, been developed through regional and sub-regional cases. These cases have noted that, on the one hand, freedom of expression goes beyond a mere aspiration of states. State Parties to human rights’ instruments are bound by an obligation to give effect to this right. On the other hand, however, freedom of expression is not absolute and can be limited where such limitation is necessary, lawful, and proportional. Within the United Republic of Tanzania, techniques have been adopted to limit the right to freedom of expression of journalists. These range from the use of national laws to fines, suspensions, and imprisoning of journalists, to extrajudicial acts such as enforced disappearances in more extreme cases. Although, these techniques are not unique to the United Republic of Tanzania as the same ill treatment of journalists’ practices can be found in other countries. This study evaluates whether the legal framework, as well as the actions of the United Republic of Tanzania, in effect, protect and promote the right to freedom of expression specifically the rights of journalists. This study is divided in five chapters which aim to provide an in-depth coverage of the human rights systems in operation that are apply to journalists in Tanzania. The study also considers limitations in the regional, subregional and national legal frameworks and concludes with recommendations that could be adopted to ensure compliance with sub-regional, regional and international standards. , Thesis (LLM) -- Faculty Law, Criminal and Procedural Law, 2022
- Full Text:
- Date Issued: 2022-12
Green Synthesis of HIV-1 Protease Inhibitors
- Authors: Hartley, Shaun Neil
- Date: 2021-10
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190145 , vital:44967
- Description: Thesis embargoed until October 2022 , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
- Authors: Hartley, Shaun Neil
- Date: 2021-10
- Subjects: Uncatalogued
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/190145 , vital:44967
- Description: Thesis embargoed until October 2022 , Thesis (MSc) -- Faculty of Science, Chemistry, 2021
- Full Text:
- Date Issued: 2021-10
An evaluation of synergistic interactions between feruloyl esterases and xylanases during the hydrolysis of various pre-treated agricultural residues
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
- Authors: Mkabayi, Lithalethu
- Date: 2021-04
- Subjects: Esterases , Xylanases , Hydrolysis , Agricultural wastes -- Recycling , Enzymes , Lignocellulose -- Biodegradation , Escherichia coli , Oligosaccharides , Hydroxycinnamic acids
- Language: English
- Type: thesis , text , Doctoral , PhD
- Identifier: http://hdl.handle.net/10962/178224 , vital:42922 , 10.21504/10962/178224
- Description: Agricultural residues are readily available and inexpensive renewable resources that can be used as raw materials for the production of value-added chemicals. The application of enzymes to facilitate the degradation of agricultural residues has long been considered the most environmentally friendly strategy for converting this material into good quality value-added chemicals. However, agricultural residues are typically lignocellulosic in composition and recalcitrant to enzymatic hydrolysis. Due to this recalcitrant nature, the complete degradation of biomass residues requires the synergistic action of a broad range of enzymes. The development and optimisation of synergistic enzyme cocktails is an effective approach for achieving high hydrolysis efficiency of lignocellulosic biomass. The aim of the current study was to evaluate the synergistic interactions between two termite metagenome-derived feruloyl esterases (FAE6 and FAE5) and endo-xylanases for the production of hydroxycinnamic acids and xylo-oligosaccharides (XOS) from model substrates, and untreated and pre-treated agricultural residues. Firstly, the two fae genes were heterologously expressed in Escherichia coli, and the recombinant enzymes were purified to homogeneity. The biochemical properties of the purified recombinant FAEs and xylanases (XT6 and Xyn11) were then assessed to determine the factors which influenced their activities and to select suitable operating conditions for synergy studies. An optimal protein loading ratio of xylanases to FAEs required to maximise the release of both reducing sugar and ferulic acid (FA) was established using 0.5% (w/v) insoluble wheat arabinoxylan (a model substrate). The enzyme combination of 66% xylanase and 33% FAE (on a protein loading basis) produced the highest amounts of reducing sugars and FA. The enzyme combination of XT6 (GH10 xylanase) and FAE5 or FAE6 liberated the highest amount of FA while a combination of Xyn11 (GH11 xylanase) and FAE5 or FAE6 produced the highest reducing sugar content. The synergistic interactions which were established between the xylanases and FAEs were further investigated using agricultural residues (corn cobs, rice straw and sugarcane bagasse). The three substrates were subjected to hydrothermal and dilute acid pre-treatment prior to synergy studies. It is generally known that, during pre-treatment, many compounds can be produced which may influence enzymatic hydrolysis. The effects of these by-products were assessed and it was found that lignin and its degradation products were the most inhibitory to the FAEs. The optimised enzyme cocktail was then applied to 1% (w/v) of untreated and pre-treated substrates for the efficient production of XOS and hydroxycinnamic acids. A significant improvement in xylanase substrate degradation was observed, especially with the combination of 66% Xyn11 and 33% FAE6 which displayed an improvement in reducing sugars of approximately 1.9-fold and 3.4-fold for hydrothermal and acid pre-treated corn cobs (compared to when Xyn11 was used alone), respectively. The study demonstrated that pre-treatment substantially enhanced the enzymatic hydrolysis of corn cobs and rice straw. Analysis of the hydrolysate product profiles revealed that the optimised enzyme cocktail displayed great potential for releasing XOS with a low degree of polymerisation. In conclusion, this study provided significant insights into the mechanism of synergistic interactions between xylanases and metagenome-derived FAEs during the hydrolysis of various substrates. The study also demonstrated that optimised enzyme cocktails combined with low severity pre-treatment can facilitate the potential use of xylan-rich lignocellulosic biomass for the production of valuable products in the future. , Thesis (PhD) -- Faculty of Science, Biochemistry and Microbiology, 2021
- Full Text:
- Date Issued: 2021-04
Effects of non-communicable diseases on labour market outcomes in South Africa
- Lawana, Nozuko https://orcid.org/0000-0003-0027-4725
- Authors: Lawana, Nozuko https://orcid.org/0000-0003-0027-4725
- Date: 2020-12
- Subjects: Labor economics , Environmental health
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20340 , vital:45656
- Description: South Africa has experienced a high and rising burden of non-communicable diseases (NCDs) and lifestyle risk factors over the past decade. Health as a category of human capital is generally ex-pected to influence an individual’s labour supply and productivity. Despite the increasing burden of non-communicable diseases, the high rate of economically inactive population and persistent wage inequalities in South Africa, there is limited empirical research on the effect of NCDs on labour force participation, employment status and wage differentials. Given this, the main object-ive of this study was to determine the effects of NCDs on three labour market outcomes: labour force participation, employment status and wage differentials in South Africa. This was divided into three major analytical objectives. Data used was extracted from the five waves of the National Income Dynamics Study, a nationally representative survey collected by the South African Labour and Development Research Unit (SALDRU). Several econometric tests, including cross-sectional data analysis, panel data analysis and the Blinder-Oaxaca decomposition methods, were used in the study. The first analytical objective focused on estimating the effect of lifestyle risk factors on labour force participation through NCDs by gender. Endogenous multivariate probit models with a recur-sive simultaneous structure were employed as a method of analysis. The empirical findings suggested that NCDs and associated risk factors have detrimental effect on labour force participation. The analysis was further expanded to analyse the effect of gender differences, considering that the effect of NCDs may be gender-specific. The results revealed that the effect of stroke and heart diseases were significant only for men, while diabetes and high blood pressure were only significant for women. The results also emphasised the significant indirect influence of obesity, physical inactivity, and alcohol consumption on labour force participation through NCDs, especially for men. The second analytical chapter focused on investigating the effect of NCDs on employment status – that is, those employed, unemployed and economically inactive in the population of South Africa by gender. The estimation technique known as generalised linear latent and mixed methods (GLLAMM) was employed to fit the multinomial logit model with correlated random intercept. The findings suggest that NCDs affect the economically inactive population significantly relative to those employed, and the magnitude is larger for women than for men. There was no significant difference found in the effect of NCDs on the unemployed relative to the employed segment of the population. In addition, the results revealed gender differences on the effect of NCDs on employment status and that stroke had a significant influence on the employment status of both sexes, while heart diseases had significant influence only in men, whereas diabetes had significant effects only in women. The last analytical chapter focuses on estimating the effect of NCDs on wage differentials in South Africa by gender. The recentred influence function regression model and Blinder-Oaxaca de-composition with RIF were used in the chapter. The empirical results revealed that the effect of NCDs on earnings differ by gender. It was found that women with NCDs earn less than those without NCDs, while men with NCDs were found to earn more than their counterparts without NCDs. The results further revealed that women with NCDs suffer from wage discrimination in South Africa. The policy implications of this study are gender-specific. The results highlight the necessity for undertaking a massive awareness campaign regarding the prevention and control of NCDs, espe-cially among women. This can be achieved through specific female health programmes, including maternal healthcare. The findings of the study imply largely that calls for gender-responsive health approaches which take into account gender-specific needs and priorities should be promoted, compared to a blanket approach. In addition, there is a need for the government to complement education policies to promote labour market outcomes. Policies aimed at increasing access to education should continue to improve access to higher education and so to enhance participation in the labour force and reduce wage gaps. , Thesis (PhD) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-12
- Authors: Lawana, Nozuko https://orcid.org/0000-0003-0027-4725
- Date: 2020-12
- Subjects: Labor economics , Environmental health
- Language: English
- Type: Doctoral theses , text
- Identifier: http://hdl.handle.net/10353/20340 , vital:45656
- Description: South Africa has experienced a high and rising burden of non-communicable diseases (NCDs) and lifestyle risk factors over the past decade. Health as a category of human capital is generally ex-pected to influence an individual’s labour supply and productivity. Despite the increasing burden of non-communicable diseases, the high rate of economically inactive population and persistent wage inequalities in South Africa, there is limited empirical research on the effect of NCDs on labour force participation, employment status and wage differentials. Given this, the main object-ive of this study was to determine the effects of NCDs on three labour market outcomes: labour force participation, employment status and wage differentials in South Africa. This was divided into three major analytical objectives. Data used was extracted from the five waves of the National Income Dynamics Study, a nationally representative survey collected by the South African Labour and Development Research Unit (SALDRU). Several econometric tests, including cross-sectional data analysis, panel data analysis and the Blinder-Oaxaca decomposition methods, were used in the study. The first analytical objective focused on estimating the effect of lifestyle risk factors on labour force participation through NCDs by gender. Endogenous multivariate probit models with a recur-sive simultaneous structure were employed as a method of analysis. The empirical findings suggested that NCDs and associated risk factors have detrimental effect on labour force participation. The analysis was further expanded to analyse the effect of gender differences, considering that the effect of NCDs may be gender-specific. The results revealed that the effect of stroke and heart diseases were significant only for men, while diabetes and high blood pressure were only significant for women. The results also emphasised the significant indirect influence of obesity, physical inactivity, and alcohol consumption on labour force participation through NCDs, especially for men. The second analytical chapter focused on investigating the effect of NCDs on employment status – that is, those employed, unemployed and economically inactive in the population of South Africa by gender. The estimation technique known as generalised linear latent and mixed methods (GLLAMM) was employed to fit the multinomial logit model with correlated random intercept. The findings suggest that NCDs affect the economically inactive population significantly relative to those employed, and the magnitude is larger for women than for men. There was no significant difference found in the effect of NCDs on the unemployed relative to the employed segment of the population. In addition, the results revealed gender differences on the effect of NCDs on employment status and that stroke had a significant influence on the employment status of both sexes, while heart diseases had significant influence only in men, whereas diabetes had significant effects only in women. The last analytical chapter focuses on estimating the effect of NCDs on wage differentials in South Africa by gender. The recentred influence function regression model and Blinder-Oaxaca de-composition with RIF were used in the chapter. The empirical results revealed that the effect of NCDs on earnings differ by gender. It was found that women with NCDs earn less than those without NCDs, while men with NCDs were found to earn more than their counterparts without NCDs. The results further revealed that women with NCDs suffer from wage discrimination in South Africa. The policy implications of this study are gender-specific. The results highlight the necessity for undertaking a massive awareness campaign regarding the prevention and control of NCDs, espe-cially among women. This can be achieved through specific female health programmes, including maternal healthcare. The findings of the study imply largely that calls for gender-responsive health approaches which take into account gender-specific needs and priorities should be promoted, compared to a blanket approach. In addition, there is a need for the government to complement education policies to promote labour market outcomes. Policies aimed at increasing access to education should continue to improve access to higher education and so to enhance participation in the labour force and reduce wage gaps. , Thesis (PhD) -- Faculty of Management and Commerce, 2020
- Full Text:
- Date Issued: 2020-12
The re-settlement of a ruined earth: Investigating the notion of “dwelling” through The design of a settlement in a post apocalyptic landscape
- Authors: Holdstock, Miranda
- Date: 2020-01
- Subjects: Landscape architecture , Restoration ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59051 , vital:60259
- Description: It is 2100 and anthropogenic climate change is well underway. Human civilisation has collapsed and those who survived the apocalypse are condemned to a life of wandering along a ruined earth; placeless; hopeless; searching for sanctuary. Our most elemental instincts will find this place, and build on it, as we always have. There, we will construct an order in the chaos of the apocalypse, by building dwelling. In an apocalyptic landscape our dependence on dwelling is only amplified. This dwelling, an evolved shelter, the beginnings of settlement, is the manifestation of its dweller’s psyche: the totality of the human mind; the conscious and unconscious; the seen and unseen. It is a chronicle of their dreamworld, memories and experiences. And, when the dweller is also the builder, the dwelling is crafted as an intricate memory-scape - which, in the climate apocalypse, is easily desecrated by the horrors of the end of the known world. Because, at our most vulnerable, when our mortality is confronted, a crisis of being occurs. Those who cannot withstand the physical and psychological suffering that the apocalypse inspires, will become non-beings: those who unconsciously long for death. To portray this, a climate refugee becomes the project’s protagonist. Through her psychological evolution, a dwelling will be built at a site to which she wandered, that represents a ruined earth, where the remains of human civilisation are left behind. Her architecture will embody principles that might facilitate survival in a hyper-harsh environment and safeguard her fragile psychology through bio-inspired and phenomenological design. The final product of this thesis will be a symbolic representation of human wandering, settling and dwelling - the origin of civilisation within chaos. Which, despite the denial of climate change, might be sooner than we think. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2020
- Full Text:
- Date Issued: 2020-01
- Authors: Holdstock, Miranda
- Date: 2020-01
- Subjects: Landscape architecture , Restoration ecology
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59051 , vital:60259
- Description: It is 2100 and anthropogenic climate change is well underway. Human civilisation has collapsed and those who survived the apocalypse are condemned to a life of wandering along a ruined earth; placeless; hopeless; searching for sanctuary. Our most elemental instincts will find this place, and build on it, as we always have. There, we will construct an order in the chaos of the apocalypse, by building dwelling. In an apocalyptic landscape our dependence on dwelling is only amplified. This dwelling, an evolved shelter, the beginnings of settlement, is the manifestation of its dweller’s psyche: the totality of the human mind; the conscious and unconscious; the seen and unseen. It is a chronicle of their dreamworld, memories and experiences. And, when the dweller is also the builder, the dwelling is crafted as an intricate memory-scape - which, in the climate apocalypse, is easily desecrated by the horrors of the end of the known world. Because, at our most vulnerable, when our mortality is confronted, a crisis of being occurs. Those who cannot withstand the physical and psychological suffering that the apocalypse inspires, will become non-beings: those who unconsciously long for death. To portray this, a climate refugee becomes the project’s protagonist. Through her psychological evolution, a dwelling will be built at a site to which she wandered, that represents a ruined earth, where the remains of human civilisation are left behind. Her architecture will embody principles that might facilitate survival in a hyper-harsh environment and safeguard her fragile psychology through bio-inspired and phenomenological design. The final product of this thesis will be a symbolic representation of human wandering, settling and dwelling - the origin of civilisation within chaos. Which, despite the denial of climate change, might be sooner than we think. , Thesis (MA) -- Faculty of Engineering, the Built Environment, and Technology, 2020
- Full Text:
- Date Issued: 2020-01
The applicability of anaerobically digested pasteurized pit latrine faecal sludge as a fertilizer to grow radish and garden cress
- Authors: Madikizela, Phindile
- Date: 2017
- Subjects: Sewage sludge as fertilizer , Sewage sludge digestion , Sewage Purification Anaerobic treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59235 , vital:27487
- Description: Pit latrine faecal sludge was recovered from numerous pit latrines in Hlalani Township, Grahamstown, South Africa. This material was used to prepare a fertilizer to demonstrate the value that could be captured from faecal sludge. Further anaerobic digestion, together with a co-feed demonstrated the potential of faecal sludge to produce low cost fertilizer that could be used to grow food crops. Biogas recovered from the anaerobic digester could be used to pasteurize its effluent, although effective biogas recovery and storage needs to be further addressed. Investigating the microbial community of the different depths of the pit latrine through molecular techniques showed that the fermenting bacteria family Clostridiaceae was the most commonly identified family throughout the different depths of the pit latrine, and that the microbial community within pit latrines was very diverse with bacterial families that are involved in nitrogen fixation, denitrification, and iron and sulphate reduction. Additionally, most of the bacterial families that dominated the seven studied pit latrines had members that were known human pathogens (Mycobacteriaceae, Dermatophilaceae Peptostreptococcaceae, Micrococcaceae, Staphylococcaceae, Leptospiraceae, Listeriaceae, Bradyrhizobiaceae and Brucellaceae). Effluent from a wastewater treatment works was selected as a co-feed to augment biogas production. The most successful faecal sludge and co-feed combination was shown to be the one made up of 33% and 66% pit latrine faecal sludge. 180 L of this effluent mixture generated 285 L of biogas over 45 days of anaerobic digestion (29±2°C). However, the recovered quantities were insufficient for pasteurization as 650 L of biogas was required to pasteurize 300 g of faecal sludge for 1 hour at 70±2°C. Therefore, liquid petroleum gas (LPG) was used as an alternative heating energy source. Anaerobic digestion and pasteurization rendered the faecal sludge safe for application as a fertilizer as the quality of the faecal sludge after treatment by anaerobic digestion and pasteurization was within the microbiological (Escherichia coli, Salmonella spp, Enterococcus faecium and helminth eggs) and trace element restrictions (Pb, Ni, Cr, Mo, As, Cu, Mn, Fe, Cd and Hg) of sludge application in agriculture as stipulated by the WHO and the South African Guidelines for Sludge Use in Agriculture. Radish (Raphanus sativus spp) and garden cress (Lepidium sativum) were cultivated to demonstrate the effectiveness of the anaerobically digested and pasteurized pit latrine faecal sludge as a fertilizer. Diluting the fertilizer prepared from faecal sludge did not reduce its efficacy and was comparable to the synthetic fertilizer used as a control in the growth trials in terms of the plant fresh weight, dry weight and plant height. Finally, the exposure to the current state of pit latrines in Hlalani Township provided an incentive to develop a new tool to address sanitation service delivery skill shortage (artisans, plant operation and maintenance workers, and sanitation and hygiene facilitators) through the use of volunteers. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
- Authors: Madikizela, Phindile
- Date: 2017
- Subjects: Sewage sludge as fertilizer , Sewage sludge digestion , Sewage Purification Anaerobic treatment
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10962/59235 , vital:27487
- Description: Pit latrine faecal sludge was recovered from numerous pit latrines in Hlalani Township, Grahamstown, South Africa. This material was used to prepare a fertilizer to demonstrate the value that could be captured from faecal sludge. Further anaerobic digestion, together with a co-feed demonstrated the potential of faecal sludge to produce low cost fertilizer that could be used to grow food crops. Biogas recovered from the anaerobic digester could be used to pasteurize its effluent, although effective biogas recovery and storage needs to be further addressed. Investigating the microbial community of the different depths of the pit latrine through molecular techniques showed that the fermenting bacteria family Clostridiaceae was the most commonly identified family throughout the different depths of the pit latrine, and that the microbial community within pit latrines was very diverse with bacterial families that are involved in nitrogen fixation, denitrification, and iron and sulphate reduction. Additionally, most of the bacterial families that dominated the seven studied pit latrines had members that were known human pathogens (Mycobacteriaceae, Dermatophilaceae Peptostreptococcaceae, Micrococcaceae, Staphylococcaceae, Leptospiraceae, Listeriaceae, Bradyrhizobiaceae and Brucellaceae). Effluent from a wastewater treatment works was selected as a co-feed to augment biogas production. The most successful faecal sludge and co-feed combination was shown to be the one made up of 33% and 66% pit latrine faecal sludge. 180 L of this effluent mixture generated 285 L of biogas over 45 days of anaerobic digestion (29±2°C). However, the recovered quantities were insufficient for pasteurization as 650 L of biogas was required to pasteurize 300 g of faecal sludge for 1 hour at 70±2°C. Therefore, liquid petroleum gas (LPG) was used as an alternative heating energy source. Anaerobic digestion and pasteurization rendered the faecal sludge safe for application as a fertilizer as the quality of the faecal sludge after treatment by anaerobic digestion and pasteurization was within the microbiological (Escherichia coli, Salmonella spp, Enterococcus faecium and helminth eggs) and trace element restrictions (Pb, Ni, Cr, Mo, As, Cu, Mn, Fe, Cd and Hg) of sludge application in agriculture as stipulated by the WHO and the South African Guidelines for Sludge Use in Agriculture. Radish (Raphanus sativus spp) and garden cress (Lepidium sativum) were cultivated to demonstrate the effectiveness of the anaerobically digested and pasteurized pit latrine faecal sludge as a fertilizer. Diluting the fertilizer prepared from faecal sludge did not reduce its efficacy and was comparable to the synthetic fertilizer used as a control in the growth trials in terms of the plant fresh weight, dry weight and plant height. Finally, the exposure to the current state of pit latrines in Hlalani Township provided an incentive to develop a new tool to address sanitation service delivery skill shortage (artisans, plant operation and maintenance workers, and sanitation and hygiene facilitators) through the use of volunteers. , Thesis (MSc) -- Faculty of Pharmacy, Pharmacy, 2017
- Full Text:
- Date Issued: 2017
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