Development of a crumb rubber adsorbent for the sorption of lead and copper from waste water: Optimization of sorption in a binary component system
- Authors: Hlabana,Relebohile Gladys
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59688 , vital:62356
- Description: Waste tyre is becoming a global environmental problem due to challenges in its disposal management and the fact that it poses fire hazards and metal leaching risk. Waste tyre can also breed mosquitos if it traps water thereby becoming an environmental health problem. There is also a portion of unused tyre in a waste tyre that is valuable and should be recycled. In South Africa waste tyre recycling is in three industries, one of which is crumb rubber where waste tyre is applied into various sized particles called crumb rubber. Crumb rubber can be applied in environmental remediation as an organic and inorganic pollutants’ adsorbent. Considering the fact that South Africa’s environment is loaded with heavy metal pollutants due to contributions by mining and agriculture as examples, it is postulated that crumb rubber produced in South Africa could be used to remediate the environment of these toxic metals. In this study adsorption of Pb (II) and Cu (II) from the synthetic waste water using waste tyre crumb rubber produced in South Africa was studied. Crumb rubber was activated using aqueous NaOH (0.02%) to make crumb rubber wettable followed by it being treated with 0.02 % acidified KMnO4 for modification of its ability to sorp positively charged metal species. Trial sorption experiments on 50 mg / L Cu (II) were successful with sorption of over 70% in 250 minutes. Final optimization of the sorption of combined Pb (II) and Cu (II) was studied using a full factorial design and optimum conditions of sorption were found to be pH 5.4; [metal] 0.617 mmol / L for Pb (II); and pH 5.4; the optimization of Cu (II) was found to be pH 5.4; [metal] 0.777 mmol / L. In Pb (II) sorptions the mechanism of adsorption on the activated crumb rubber was found to be following the Freundlich model indicating that the adsorption seemed to occur on a multilayer adsorbent, while the mechanism of copper(II) adsorption on to the activated crumb rubber was found to be following Langmuir model, indicating that the adsorption seemed to occur on a monolayer. With adsorption percentages ranging from 98.2 % to 100.0 %, for Pb (II), the crumb rubber produced under the conditions of this study, can be used in South Africa for selective removal of Pb (II). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Hlabana,Relebohile Gladys
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59688 , vital:62356
- Description: Waste tyre is becoming a global environmental problem due to challenges in its disposal management and the fact that it poses fire hazards and metal leaching risk. Waste tyre can also breed mosquitos if it traps water thereby becoming an environmental health problem. There is also a portion of unused tyre in a waste tyre that is valuable and should be recycled. In South Africa waste tyre recycling is in three industries, one of which is crumb rubber where waste tyre is applied into various sized particles called crumb rubber. Crumb rubber can be applied in environmental remediation as an organic and inorganic pollutants’ adsorbent. Considering the fact that South Africa’s environment is loaded with heavy metal pollutants due to contributions by mining and agriculture as examples, it is postulated that crumb rubber produced in South Africa could be used to remediate the environment of these toxic metals. In this study adsorption of Pb (II) and Cu (II) from the synthetic waste water using waste tyre crumb rubber produced in South Africa was studied. Crumb rubber was activated using aqueous NaOH (0.02%) to make crumb rubber wettable followed by it being treated with 0.02 % acidified KMnO4 for modification of its ability to sorp positively charged metal species. Trial sorption experiments on 50 mg / L Cu (II) were successful with sorption of over 70% in 250 minutes. Final optimization of the sorption of combined Pb (II) and Cu (II) was studied using a full factorial design and optimum conditions of sorption were found to be pH 5.4; [metal] 0.617 mmol / L for Pb (II); and pH 5.4; the optimization of Cu (II) was found to be pH 5.4; [metal] 0.777 mmol / L. In Pb (II) sorptions the mechanism of adsorption on the activated crumb rubber was found to be following the Freundlich model indicating that the adsorption seemed to occur on a multilayer adsorbent, while the mechanism of copper(II) adsorption on to the activated crumb rubber was found to be following Langmuir model, indicating that the adsorption seemed to occur on a monolayer. With adsorption percentages ranging from 98.2 % to 100.0 %, for Pb (II), the crumb rubber produced under the conditions of this study, can be used in South Africa for selective removal of Pb (II). , Thesis (MSc) -- Faculty of Science, School of Biomolecular and Chemical Sciences, 2022
- Full Text:
- Date Issued: 2022-12
The co-evolution of Africa’s eastern margin and its primate fauna: implications for hominin evolution
- Authors: Mambalu, Philasande
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59755 , vital:62418
- Description: I investigated potential links between the diversification of African primate lineages and the physical evolution of the continent. I compared published phylogenetic trees based on mitochondrial and nuclear DNA for five clades: (a) Lorisoidea (galagos and pottos); (b) arboreal guenon monkeys (Cercopithecus and its allies); (c) living apes (including humans); (d) Papionini (baboons); and (e) savanna or “vervet” monkeys (Chlorocebus). I compared primate divergence dates with the ages of tectonic events, patterns of climatic change, and their palaeo-vegetational consequences. Based on present primate distributions, I estimated likely geographic locations of the divergence events. Finally, I compared the phylogenetic patterns of the primate clades with hominin evolutionary scenarios. Phylogenetic comparisons indicated three time periods when rates of speciation increased across the five primate clades: the Eocene – Oligocene transition (34 – 32 Ma); the mid-late Miocene (10 – 5 Ma); and the Pliocene – Pleistocene transition (2.7 – 2.3 Ma). Concentrated bursts of lineage splitting indicate a broadscale causal relationship between environmental change and lineage divergence. Human evolution followed similar biogeographic patterns to those of other primate clades. Tectonic events, climatic changes and palaeo-vegetational shifts are intimately connected, and have synergistic effects on biotic diversity. Tectonic events influence climatic change through their effects on oceanic circulation, planetary temperatures and rainfall patterns. Additionally, tectonic uplift and erosion may create geographic barriers to organismal dispersal across the continent, increasing the likelihood of geographic separation of populations and speciation. Recently evolved primate species show high levels of hybridisation for several generations after their initial divergence. Genus Homo generated ~10 species over 2.5 Ma. The emergence of these taxa likely involved substantial hybridisation, as demonstrated by the presence of Neanderthal genes within the H. sapiens genome. I suggest that this hybridisation contributed to the difficulties palaeoanthropologists often experience in distinguishing fossil hominin taxa. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
- Authors: Mambalu, Philasande
- Date: 2022-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/59755 , vital:62418
- Description: I investigated potential links between the diversification of African primate lineages and the physical evolution of the continent. I compared published phylogenetic trees based on mitochondrial and nuclear DNA for five clades: (a) Lorisoidea (galagos and pottos); (b) arboreal guenon monkeys (Cercopithecus and its allies); (c) living apes (including humans); (d) Papionini (baboons); and (e) savanna or “vervet” monkeys (Chlorocebus). I compared primate divergence dates with the ages of tectonic events, patterns of climatic change, and their palaeo-vegetational consequences. Based on present primate distributions, I estimated likely geographic locations of the divergence events. Finally, I compared the phylogenetic patterns of the primate clades with hominin evolutionary scenarios. Phylogenetic comparisons indicated three time periods when rates of speciation increased across the five primate clades: the Eocene – Oligocene transition (34 – 32 Ma); the mid-late Miocene (10 – 5 Ma); and the Pliocene – Pleistocene transition (2.7 – 2.3 Ma). Concentrated bursts of lineage splitting indicate a broadscale causal relationship between environmental change and lineage divergence. Human evolution followed similar biogeographic patterns to those of other primate clades. Tectonic events, climatic changes and palaeo-vegetational shifts are intimately connected, and have synergistic effects on biotic diversity. Tectonic events influence climatic change through their effects on oceanic circulation, planetary temperatures and rainfall patterns. Additionally, tectonic uplift and erosion may create geographic barriers to organismal dispersal across the continent, increasing the likelihood of geographic separation of populations and speciation. Recently evolved primate species show high levels of hybridisation for several generations after their initial divergence. Genus Homo generated ~10 species over 2.5 Ma. The emergence of these taxa likely involved substantial hybridisation, as demonstrated by the presence of Neanderthal genes within the H. sapiens genome. I suggest that this hybridisation contributed to the difficulties palaeoanthropologists often experience in distinguishing fossil hominin taxa. , Thesis (MSc) -- Faculty of Science, School of Environmental Sciences, 2022
- Full Text:
- Date Issued: 2022-12
The principle of fairness in South African criminal trials
- Authors: Ndude, Tembinkosi
- Date: 2022-12
- Subjects: Criminal law , Criminal law -- cases , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60090 , vital:62984
- Description: The purpose of this research is to determine the presence of the principle of fairness during criminal trials in South Africa. In determining the presence of the principle, this research will provide a short background on both the historical pre-constitution situation on the principle of fairness and the present situation on how courts in South Africa conduct themselves in the adjudication of criminal cases in ensuring fair criminal trials. The historical background partially highlights certain provisions of the Criminal Procedure Act in curtailing both the application of due processes and entrenchment of fairness during criminal trials. The arguments on the principle of fairness during criminal trials are discussed in tandem with the principle of the rule of law in the determination of the resolve our justice system has, and the use of designated legal instruments to assert the principle of fairness, for example, section 35(3) of the Constitution and the provisions of the Criminal Procedure Act 51 of 1977(herein referred "the Act") including the determination of the level of judicial interference, independence, and impartiality. The challenges of unfair trials are also explained against the concept of ubuntu which is a foundational element of fairness expressed and interpreted as such by the indigenous people living in South Africa. In the Port Elizabeth Municipality v Various Occupiers, the court describes the concept of ubuntu as part of a deep cultural heritage central to fairness and fair treatment of humans. The principle of fairness in our criminal trials is a transformative element shaped by our historical background. This is evident in S v Zuma which refers to section 25 of the Interim Constitution. The transformative element shaping principle of fairness is discussed in conjunction with section 35(3) of the new Constitution and case law. This research also notes the adversarial element of our criminal trials having considered some of the evidentiary burdens, for example, the onus of proof, rebuttal of evidence, proof beyond reasonable doubt, reverse onus, circumstantial evidence, presumption, and the adverse inference. However, these evidentiary burdens are addressed by section 35(3) of the Constitution and case law, for example the right to remain silent, the right to be presumed innocent, the right not to be compelled to give self-incriminating evidence, to be informed of the charge with sufficient detail to answer it, to choose, and be represented by a legal practitioner and to be informed of this right promptly. This work views the principle of fairness as a mechanism focussing on relegating unjustness and the ill treatment of accused persons during criminal trials to the dustbin of history. , Thesis (LLM) -- Faculty of Law, Department Criminal and Procedural Law, 2022
- Full Text: false
- Date Issued: 2022-12
- Authors: Ndude, Tembinkosi
- Date: 2022-12
- Subjects: Criminal law , Criminal law -- cases , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/60090 , vital:62984
- Description: The purpose of this research is to determine the presence of the principle of fairness during criminal trials in South Africa. In determining the presence of the principle, this research will provide a short background on both the historical pre-constitution situation on the principle of fairness and the present situation on how courts in South Africa conduct themselves in the adjudication of criminal cases in ensuring fair criminal trials. The historical background partially highlights certain provisions of the Criminal Procedure Act in curtailing both the application of due processes and entrenchment of fairness during criminal trials. The arguments on the principle of fairness during criminal trials are discussed in tandem with the principle of the rule of law in the determination of the resolve our justice system has, and the use of designated legal instruments to assert the principle of fairness, for example, section 35(3) of the Constitution and the provisions of the Criminal Procedure Act 51 of 1977(herein referred "the Act") including the determination of the level of judicial interference, independence, and impartiality. The challenges of unfair trials are also explained against the concept of ubuntu which is a foundational element of fairness expressed and interpreted as such by the indigenous people living in South Africa. In the Port Elizabeth Municipality v Various Occupiers, the court describes the concept of ubuntu as part of a deep cultural heritage central to fairness and fair treatment of humans. The principle of fairness in our criminal trials is a transformative element shaped by our historical background. This is evident in S v Zuma which refers to section 25 of the Interim Constitution. The transformative element shaping principle of fairness is discussed in conjunction with section 35(3) of the new Constitution and case law. This research also notes the adversarial element of our criminal trials having considered some of the evidentiary burdens, for example, the onus of proof, rebuttal of evidence, proof beyond reasonable doubt, reverse onus, circumstantial evidence, presumption, and the adverse inference. However, these evidentiary burdens are addressed by section 35(3) of the Constitution and case law, for example the right to remain silent, the right to be presumed innocent, the right not to be compelled to give self-incriminating evidence, to be informed of the charge with sufficient detail to answer it, to choose, and be represented by a legal practitioner and to be informed of this right promptly. This work views the principle of fairness as a mechanism focussing on relegating unjustness and the ill treatment of accused persons during criminal trials to the dustbin of history. , Thesis (LLM) -- Faculty of Law, Department Criminal and Procedural Law, 2022
- Full Text: false
- Date Issued: 2022-12
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