Nanozeolite-functionalized poly(lactic acid) ultrafiltration membranes for water treatment
- Authors: Matseke, Mphoma Sophy
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Membrane filters , Ultrafiltration , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84691 , uj:19252
- Description: Abstract: Water is a scarce resource. This resource deteriorates everyday due to industrial and agricultural activities and other detrimental human activities. Many techniques are already in place for the treatment of drinking water. Membrane technologies have become popular in water treatment in recent times. However, conventional membrane techniques have several drawbacks such as hydrophobicity, low mechanical strength, low chemical reactivity and high propensity of fouling. Ultrafiltration (UF) membranes, in particular, have gained considerable attention in water treatment applications due to their low costs and easy maintenance compared to their counterparts. These membranes utilize known polymer backbones such as polyethersulfone (PES), polysulfone (PSf), and polyvinylfluoride (PVDF). However, the permeabilities for these membranes reduce drastically during water treatment processes. This is due to fouling that occurs on the membrane surface. Membrane fouling is generally caused by adsorption of solutes on the membrane surface and/or the blocking of the membrane pores. Further, UF membranes made from these polymers have low mechanical strength and therefore easily break up when subjected to high pressure systems. This subsequently results in an increase in operating costs and a decrease in overall performance and life-span of the membrane... , M.Sc.
- Full Text:
- Authors: Matseke, Mphoma Sophy
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Membrane filters , Ultrafiltration , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84691 , uj:19252
- Description: Abstract: Water is a scarce resource. This resource deteriorates everyday due to industrial and agricultural activities and other detrimental human activities. Many techniques are already in place for the treatment of drinking water. Membrane technologies have become popular in water treatment in recent times. However, conventional membrane techniques have several drawbacks such as hydrophobicity, low mechanical strength, low chemical reactivity and high propensity of fouling. Ultrafiltration (UF) membranes, in particular, have gained considerable attention in water treatment applications due to their low costs and easy maintenance compared to their counterparts. These membranes utilize known polymer backbones such as polyethersulfone (PES), polysulfone (PSf), and polyvinylfluoride (PVDF). However, the permeabilities for these membranes reduce drastically during water treatment processes. This is due to fouling that occurs on the membrane surface. Membrane fouling is generally caused by adsorption of solutes on the membrane surface and/or the blocking of the membrane pores. Further, UF membranes made from these polymers have low mechanical strength and therefore easily break up when subjected to high pressure systems. This subsequently results in an increase in operating costs and a decrease in overall performance and life-span of the membrane... , M.Sc.
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Electrospun antibacterial cyclodextrin and chitosan based nanocomposite filtration materials for use in drinking water purification
- Authors: Nthunya, Lebea Nathnael
- Date: 2016
- Subjects: Water - Purification - Organic compounds removal , Nanostructured materials , Nanofibers , Electrospinning , Cyclodextrins
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/85070 , uj:19298
- Description: Abstract: The quality of drinking water sources in a rural settlement within the Chief Albert Luthuli Local Municipality in Mpumalanga, South Africa was studied over a period of 8 months (from June 2014 – February 2015). Specifically the community that was used as a case study in this project is Lochiel, which has approximately 5000 residents. The community has no supply of purified water. It relies on open wells and boreholes as direct sources of drinking water and water for domestic purposes. At the inception of the study, no existing information could be found on the quality of these drinking water sources. The quality of these water sources was studied by determining the levels of toxic metals, organics, and bacteria using a range of analytical methods. The results obtained showed that the quality of the drinking water was generally acceptable and differed for each source and with change in seasons of the year. However, the study revealed that the concentrations of Co, Pb, Mn, Fe, chlorophenols, nitrophenols, E. coli and total coliforms were higher than the acceptable limits in some of the sources. In an attempt to develop materials to remove the detected pollutants in the water sources, antibacterial nanofibres based on chitosan (CS) and β-cyclodextrins (β- CDs) were synthesized for use in a point-of-use (POU) system. The CS and -CDs polymer powders were chosen due to their remarkable properties such as biodegradability, biocompatibility, low toxicity, gratifying design flexibility and cost effectiveness. The polymer powders were fabricated in the form of nanofibres using an electrospinning technique. Their ability to be electrospun was enhanced by the addition of other polymers prior to the preparation of the electrospinning solutions. Polyacrylamide (PAA), polyethylene glycol (PEG) and polyisoprene (PIP) were blended with CS to prevent its stream break-up, reduce its surface tension, improve its entanglement during electrospinning (polymers with high molecular weight assist in formation and entanglement of the jet, thereby resulting in fibre formation) and to reduce the swelling capacity of the synthesized nanofibres. Uniform non-beaded CS based nanofibres were obtained by electrospinning a CS polymer solution containing CS:PAA = 3.5:1, 5% PEG and 80% PIP relative to the CS. The optimum electrospinning conditions for the CS based nanofibres were: injection flow rate of 0.7 mL·h-1, a distance of 22 cm between the tip of the needle and the collector and a... , M.Sc. (Chemistry)
- Full Text:
- Authors: Nthunya, Lebea Nathnael
- Date: 2016
- Subjects: Water - Purification - Organic compounds removal , Nanostructured materials , Nanofibers , Electrospinning , Cyclodextrins
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/85070 , uj:19298
- Description: Abstract: The quality of drinking water sources in a rural settlement within the Chief Albert Luthuli Local Municipality in Mpumalanga, South Africa was studied over a period of 8 months (from June 2014 – February 2015). Specifically the community that was used as a case study in this project is Lochiel, which has approximately 5000 residents. The community has no supply of purified water. It relies on open wells and boreholes as direct sources of drinking water and water for domestic purposes. At the inception of the study, no existing information could be found on the quality of these drinking water sources. The quality of these water sources was studied by determining the levels of toxic metals, organics, and bacteria using a range of analytical methods. The results obtained showed that the quality of the drinking water was generally acceptable and differed for each source and with change in seasons of the year. However, the study revealed that the concentrations of Co, Pb, Mn, Fe, chlorophenols, nitrophenols, E. coli and total coliforms were higher than the acceptable limits in some of the sources. In an attempt to develop materials to remove the detected pollutants in the water sources, antibacterial nanofibres based on chitosan (CS) and β-cyclodextrins (β- CDs) were synthesized for use in a point-of-use (POU) system. The CS and -CDs polymer powders were chosen due to their remarkable properties such as biodegradability, biocompatibility, low toxicity, gratifying design flexibility and cost effectiveness. The polymer powders were fabricated in the form of nanofibres using an electrospinning technique. Their ability to be electrospun was enhanced by the addition of other polymers prior to the preparation of the electrospinning solutions. Polyacrylamide (PAA), polyethylene glycol (PEG) and polyisoprene (PIP) were blended with CS to prevent its stream break-up, reduce its surface tension, improve its entanglement during electrospinning (polymers with high molecular weight assist in formation and entanglement of the jet, thereby resulting in fibre formation) and to reduce the swelling capacity of the synthesized nanofibres. Uniform non-beaded CS based nanofibres were obtained by electrospinning a CS polymer solution containing CS:PAA = 3.5:1, 5% PEG and 80% PIP relative to the CS. The optimum electrospinning conditions for the CS based nanofibres were: injection flow rate of 0.7 mL·h-1, a distance of 22 cm between the tip of the needle and the collector and a... , M.Sc. (Chemistry)
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Fabrication of novel pei-based antimicrobial metal-organic nanocomposites for the treatment of wastewater
- Authors: Sambaza, Shepherd Sundayi
- Date: 2016
- Subjects: Antimicrobial polymers , Water - Purification - Microbial removal , Water - Purification - Membrane filtration , Nanoparticles
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84797 , uj:19263
- Description: Abstract: Wastewater is contaminated with inorganic and organic compounds through a number of activities including industrial, agricultural and human activities. Current wastewater treatment technologies such as membrane technology, ion exchange, electrolysis and bioremediation are not always efficient in removing these contaminants to parts per billion (ppb) levels. New techniques need to be developed that are reasonably inexpensive, easy to use, environmentally friendly and more efficient in removing toxic metals and other compounds to acceptable levels. Adsorption of toxic contaminants in water using polyethyleneimine (PEI)-based composite materials has the potential to meet these criteria. This work reports on the synthesis of branched PEI, its insoluble form (CPEI) and its cross-linking with multi-walled carbon nanotubes (MWCNTs) to form PEI-MWCNT nanocomposites. The PEI-MWCNT polymeric nanocomposite adsorbents were evaluated for the removal of Cr6+ and Pb2+ from contaminated water. Branched PEI was used as the polymer material of choice because of its chelating properties and the ability to add specific functional groups on its structure. Functionalized MWCNTs (0.5 - 2.5% w/w), with average diameter of 25 nm were incorporated into PEI to provide mechanical robustness to the resulting nanocomposite polymers. The presence of acidic functional groups on the functionalized materials (CPEI and PEI-MWCNTs) was confirmed by measuring the surface charge as a function of pH (zeta potential measurements). Fourier transform infrared (FTIR) analysis confirmed the formation of a new bond between the functional groups on the MWCNTs and PEI, as evidenced by the appearance of a –C=O peak at 1716 cm-1 in the FTIR spectra of PEI-MWCNTs. Batch adsorption and kinetic studies were carried out to evaluate the performance of the PEI-MWCNT nanocomposite materials for the removal of Cr6+ from simulated water samples... , M.Sc. (Chemistry)
- Full Text:
- Authors: Sambaza, Shepherd Sundayi
- Date: 2016
- Subjects: Antimicrobial polymers , Water - Purification - Microbial removal , Water - Purification - Membrane filtration , Nanoparticles
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84797 , uj:19263
- Description: Abstract: Wastewater is contaminated with inorganic and organic compounds through a number of activities including industrial, agricultural and human activities. Current wastewater treatment technologies such as membrane technology, ion exchange, electrolysis and bioremediation are not always efficient in removing these contaminants to parts per billion (ppb) levels. New techniques need to be developed that are reasonably inexpensive, easy to use, environmentally friendly and more efficient in removing toxic metals and other compounds to acceptable levels. Adsorption of toxic contaminants in water using polyethyleneimine (PEI)-based composite materials has the potential to meet these criteria. This work reports on the synthesis of branched PEI, its insoluble form (CPEI) and its cross-linking with multi-walled carbon nanotubes (MWCNTs) to form PEI-MWCNT nanocomposites. The PEI-MWCNT polymeric nanocomposite adsorbents were evaluated for the removal of Cr6+ and Pb2+ from contaminated water. Branched PEI was used as the polymer material of choice because of its chelating properties and the ability to add specific functional groups on its structure. Functionalized MWCNTs (0.5 - 2.5% w/w), with average diameter of 25 nm were incorporated into PEI to provide mechanical robustness to the resulting nanocomposite polymers. The presence of acidic functional groups on the functionalized materials (CPEI and PEI-MWCNTs) was confirmed by measuring the surface charge as a function of pH (zeta potential measurements). Fourier transform infrared (FTIR) analysis confirmed the formation of a new bond between the functional groups on the MWCNTs and PEI, as evidenced by the appearance of a –C=O peak at 1716 cm-1 in the FTIR spectra of PEI-MWCNTs. Batch adsorption and kinetic studies were carried out to evaluate the performance of the PEI-MWCNT nanocomposite materials for the removal of Cr6+ from simulated water samples... , M.Sc. (Chemistry)
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Greener synthesis of biopolymer-inorganic nanocomposite beads and membranes for use in water purification
- Authors: Masheane, Monaheng Leonard
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Water - Purification , Nanocomposites (Materials) , Nanotechnology , Biopolymers
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84682 , uj:19251
- Description: Abstract: In South Africa, the unavailability of clean drinking water is a life-threatening problem, especially in the rural areas. Millions of people living in rural areas rely on water directly from the source (surface and groundwater) for drinking, cooking and other domestic purposes without any prior treatment. These sources of water are known to be affected by contaminants from untreated wastewater, industrial effluent, agricultural runoffs and domestic waste. The exposure of humans to these polluted water bodies results in infection and waterborne diseases which sometimes result in death. This has a direct consequence to the productivity of the people living in these communities and has cost implications to the government. This study was aimed at determining the potential pollutants present in drinking water sources in Lochiel, a small community in the Mpumalanga province, eastern part of South Africa, and to develop efficient and cost effective materials (beads and membranes) that could be used in the rural communities to provide safe and clean water for consumption. The application of adsorption materials (e.g. in the form of beads) and filtration materials (e.g. membranes) has attracted great interest in water purification. This is because they have several advantages over the conventional methods. These advantages include but are not limited to low capital and operations costs, low energy requirements (especially when chemically modified) and ease of operation. In this study chitosan (CTs) was chosen to prepare novel and environmentally benign nanocomposite materials either in the form of beads or flat sheet using greener solvents. In an attempt to prepare biopolymer-ceramic nanofiltration composite membranes, small amounts of multiwalled carbon nanotubes (MWCNTs) (5 wt%) and alumina (Al) (20 wt%) were added to CTs in pH controlled aqueous media near room temperature. The resulting nanocomposite was found to readily form insoluble beads... , M.Sc. (Chemistry)
- Full Text:
- Authors: Masheane, Monaheng Leonard
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Water - Purification , Nanocomposites (Materials) , Nanotechnology , Biopolymers
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84682 , uj:19251
- Description: Abstract: In South Africa, the unavailability of clean drinking water is a life-threatening problem, especially in the rural areas. Millions of people living in rural areas rely on water directly from the source (surface and groundwater) for drinking, cooking and other domestic purposes without any prior treatment. These sources of water are known to be affected by contaminants from untreated wastewater, industrial effluent, agricultural runoffs and domestic waste. The exposure of humans to these polluted water bodies results in infection and waterborne diseases which sometimes result in death. This has a direct consequence to the productivity of the people living in these communities and has cost implications to the government. This study was aimed at determining the potential pollutants present in drinking water sources in Lochiel, a small community in the Mpumalanga province, eastern part of South Africa, and to develop efficient and cost effective materials (beads and membranes) that could be used in the rural communities to provide safe and clean water for consumption. The application of adsorption materials (e.g. in the form of beads) and filtration materials (e.g. membranes) has attracted great interest in water purification. This is because they have several advantages over the conventional methods. These advantages include but are not limited to low capital and operations costs, low energy requirements (especially when chemically modified) and ease of operation. In this study chitosan (CTs) was chosen to prepare novel and environmentally benign nanocomposite materials either in the form of beads or flat sheet using greener solvents. In an attempt to prepare biopolymer-ceramic nanofiltration composite membranes, small amounts of multiwalled carbon nanotubes (MWCNTs) (5 wt%) and alumina (Al) (20 wt%) were added to CTs in pH controlled aqueous media near room temperature. The resulting nanocomposite was found to readily form insoluble beads... , M.Sc. (Chemistry)
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