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
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- Date Issued: 2022-12
Ifuthe lenkolo yobuKristu kulwimi lwesiXhosa
- Authors: Mwanda, Siyasanga Pulani
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54511 , vital:46617
- Description: Le ngxongxo iza kuthi ithethe ngefuthe lenkolo yobuKristu kulwimi lwesiXhosa. Akuyomfihlo ukuba ulwimi luthi lukhule okanye ludodobale ngenxa yendlela abantu bolwimi abaphila ngayo notshintsho oluthi lubekho kwindlela abaphila ngayo. AmaXhosa ke athi nawo aziswa kwinkolo yobuKristu. Le ngxoxo iza kuthi icacise ngokuthe gca ithiyori yeSimiyotiki esisiseko sesi sifundo, idakance iizimvo zeengcali zeSimiyotiki, ize ke iveze amagama amatsha ayengekho esiXhoseni mhla mnene, intsusa yalamagama nentsingiselo yawo. Okwesibini izakuthi ivelele intsingiselo yemiqondiso neempawu zobuKristu negalelo lazo kulwimi lwesiXhosa. Okokugqibela iza kuthi iveze izaci namaqhalo esiXhosa angobuKristu. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
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- Date Issued: 2021-12
- Authors: Mwanda, Siyasanga Pulani
- Date: 2021-12
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/54511 , vital:46617
- Description: Le ngxongxo iza kuthi ithethe ngefuthe lenkolo yobuKristu kulwimi lwesiXhosa. Akuyomfihlo ukuba ulwimi luthi lukhule okanye ludodobale ngenxa yendlela abantu bolwimi abaphila ngayo notshintsho oluthi lubekho kwindlela abaphila ngayo. AmaXhosa ke athi nawo aziswa kwinkolo yobuKristu. Le ngxoxo iza kuthi icacise ngokuthe gca ithiyori yeSimiyotiki esisiseko sesi sifundo, idakance iizimvo zeengcali zeSimiyotiki, ize ke iveze amagama amatsha ayengekho esiXhoseni mhla mnene, intsusa yalamagama nentsingiselo yawo. Okwesibini izakuthi ivelele intsingiselo yemiqondiso neempawu zobuKristu negalelo lazo kulwimi lwesiXhosa. Okokugqibela iza kuthi iveze izaci namaqhalo esiXhosa angobuKristu. , Thesis (MA) -- Faculty of Humanities, School of Language, Media and Communication, 2021
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- Date Issued: 2021-12
Professional, personal and corporate ethics challenges during infrastructure delivery
- Authors: Dyariwe, Abongile
- Date: 2015-01
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53300 , vital:45131
- Description: Purpose of this treatise: This study is aimed at investigating whether there is a lack of professional- and, personal ethics, and a lack of enforcing corporate ethics from the Built environment professionals working for Eskom ECOU. Design/methodology/approach: The research approach used for the study was mainly quantitative. The quantitative methods used were descriptive and non-parametric statistical methods (Kruskal- Wallis Test and Mann-Whitney U Test). The selected sample for the study was categorised as internal stakeholders (i.e. employees that are permanently employed by Eskom) and external stakeholders (i.e. people that are employed by Eskom on a contract basis as quantity surveying, project management and engineering consultants) The scope of the study was to determine whether there are professional-, personal- and corporate ethical challenges in client organisations. A literature review was conducted; and all the relevant literature relating to professional-, personal- and corporate ethics in client organisations was collated, and then used to develop a questionnaire. The questionnaires were distributed to internal and external stakeholders, who were involved during infrastructural delivery in client organisations, in order to acquire different views on ethical perceptions. The data obtained from the questionnaires were analysed, and used to test if the hypotheses were supported or not. Findings: The findings of this study revealed that the demographic profile does not have any significant influence on the ratings of internal and external stakeholders’ perceptions of the lack of professional and personal ethics – or on the enforcement of corporate ethics. Furthermore, this study also revealed that there is no significant difference in the ethical perceptions of internal and external stakeholders, on the enforcement of a professional and corporate ethical culture. Lastly, only in the personal ethics section there is a significant difference in ethical perception. In relation to the statement of the problem, the findings of this study revealed that internal and external stakeholders’ lack of professional- and personal ethics and the enforcement of corporate ethics are largely unknown. Research limitations: This study was limited to only Built environment professionals (including service providers) working for Eskom ECOU. Practical implications: The study revealed that there are ethical challenges in client organisations, even though they might be largely unknown. This clearly shows that construction industry professionals are all susceptible to unethical behaviour. Therefore, Eskom ECOU should refrain from only focusing on unethical behaviour by contractors and consulting firms; and it should also look at the client’s Built environment professionals; because there is evidence that they are also suspect during infrastructural delivery. , Thesis (MSc) -- Faculty of Engineering, the Built Environment and Information Technology, School of the Built Environment and Civil Engineering, 2021
- Full Text:
- Date Issued: 2015-01
- Authors: Dyariwe, Abongile
- Date: 2015-01
- Subjects: Port Elizabeth (South Africa) , Eastern Cape (South Africa) , South Africa
- Language: English
- Type: Master's theses , text
- Identifier: http://hdl.handle.net/10948/53300 , vital:45131
- Description: Purpose of this treatise: This study is aimed at investigating whether there is a lack of professional- and, personal ethics, and a lack of enforcing corporate ethics from the Built environment professionals working for Eskom ECOU. Design/methodology/approach: The research approach used for the study was mainly quantitative. The quantitative methods used were descriptive and non-parametric statistical methods (Kruskal- Wallis Test and Mann-Whitney U Test). The selected sample for the study was categorised as internal stakeholders (i.e. employees that are permanently employed by Eskom) and external stakeholders (i.e. people that are employed by Eskom on a contract basis as quantity surveying, project management and engineering consultants) The scope of the study was to determine whether there are professional-, personal- and corporate ethical challenges in client organisations. A literature review was conducted; and all the relevant literature relating to professional-, personal- and corporate ethics in client organisations was collated, and then used to develop a questionnaire. The questionnaires were distributed to internal and external stakeholders, who were involved during infrastructural delivery in client organisations, in order to acquire different views on ethical perceptions. The data obtained from the questionnaires were analysed, and used to test if the hypotheses were supported or not. Findings: The findings of this study revealed that the demographic profile does not have any significant influence on the ratings of internal and external stakeholders’ perceptions of the lack of professional and personal ethics – or on the enforcement of corporate ethics. Furthermore, this study also revealed that there is no significant difference in the ethical perceptions of internal and external stakeholders, on the enforcement of a professional and corporate ethical culture. Lastly, only in the personal ethics section there is a significant difference in ethical perception. In relation to the statement of the problem, the findings of this study revealed that internal and external stakeholders’ lack of professional- and personal ethics and the enforcement of corporate ethics are largely unknown. Research limitations: This study was limited to only Built environment professionals (including service providers) working for Eskom ECOU. Practical implications: The study revealed that there are ethical challenges in client organisations, even though they might be largely unknown. This clearly shows that construction industry professionals are all susceptible to unethical behaviour. Therefore, Eskom ECOU should refrain from only focusing on unethical behaviour by contractors and consulting firms; and it should also look at the client’s Built environment professionals; because there is evidence that they are also suspect during infrastructural delivery. , Thesis (MSc) -- Faculty of Engineering, the Built Environment and Information Technology, School of the Built Environment and Civil Engineering, 2021
- Full Text:
- Date Issued: 2015-01
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