A practical course on filter assessment for water treatment plant operators
- Van Staden, S.J., Haarhoff, J.
- Authors: Van Staden, S.J. , Haarhoff, J.
- Date: 2011
- Subjects: Water - Purification - Membrane filtration , Water treatment plants , Plant operators, Training of
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17261 , uj:15863 , Van Staden, S.J. & Haarhoff, J. (2011) A practical course on filter assessment for water treatment plant operators. In: Proceedings of the 2nd Young Water Professionals of Southern Africa Conference, Pretoria, South Africa, 4-5 July 2011, 5 p.
- Description: Abstract Training of treatment plant operators in South Africa faces some special problems. First, the political changes in the past decade led to a complete restructuring of local government. An integral part of the ongoing restructuring process is an aggressive programme for black economic empowerment. This brought many new faces into local government without the practical experience to which the water industry is accustomed, coupled with a massive displacement of technical skills from the sector. From 1989, the number of civil engineering professionals (engineers, technologists, technicians) has dwindled from 22 / 100000 of the population to 3 / 100000 of the population in 2007 (Lawless, 2007). Second, the Water Services Act (1997) of South Africa shifted the burden of water supply squarely on the shoulders of district and local municipalities. The dilution of skills, coupled with increasing responsibility, makes it clear that the water sector in South Africa will have to train itself out of this predicament. As a result, the quality and focus of training programmes, especially at the operator level, is receiving renewed attention. This paper shares the experience of the development and refinement of a training course for filter assessment for operators over the past eight years.
- Full Text:
- Authors: Van Staden, S.J. , Haarhoff, J.
- Date: 2011
- Subjects: Water - Purification - Membrane filtration , Water treatment plants , Plant operators, Training of
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17261 , uj:15863 , Van Staden, S.J. & Haarhoff, J. (2011) A practical course on filter assessment for water treatment plant operators. In: Proceedings of the 2nd Young Water Professionals of Southern Africa Conference, Pretoria, South Africa, 4-5 July 2011, 5 p.
- Description: Abstract Training of treatment plant operators in South Africa faces some special problems. First, the political changes in the past decade led to a complete restructuring of local government. An integral part of the ongoing restructuring process is an aggressive programme for black economic empowerment. This brought many new faces into local government without the practical experience to which the water industry is accustomed, coupled with a massive displacement of technical skills from the sector. From 1989, the number of civil engineering professionals (engineers, technologists, technicians) has dwindled from 22 / 100000 of the population to 3 / 100000 of the population in 2007 (Lawless, 2007). Second, the Water Services Act (1997) of South Africa shifted the burden of water supply squarely on the shoulders of district and local municipalities. The dilution of skills, coupled with increasing responsibility, makes it clear that the water sector in South Africa will have to train itself out of this predicament. As a result, the quality and focus of training programmes, especially at the operator level, is receiving renewed attention. This paper shares the experience of the development and refinement of a training course for filter assessment for operators over the past eight years.
- Full Text:
Composite membranes modified with functionalized cyclodextrins for water treatment
- Authors: Mbuli, Bhekani Sydney
- Date: 2014-07-15
- Subjects: Polyamide membranes , Cyclodextrins , Water - Purification - Membrane filtration
- Type: Thesis
- Identifier: uj:11673 , http://hdl.handle.net/10210/11396
- Description: Ph.D. (Chemistry) , This thesis describes the modification of polyamide thin-film composite (TFC) membranes with amino- and diethylamino-cyclodextrins (CDs) using an interfacial polymerisation process. An in situ modification procedure was carried out using different concentrations of amino functionalized CDs (α-CDs and β-CDs) dispersed in m-phenylenediamine in water. These aqueous solutions were then reacted with trimesoyl chloride (TMC) on polyethersulphone (PES) ultrafiltration support membranes. Contact-angle measurements of the modified polyamide TFC membranes demonstrates improved hydrophilic properties due to additional –OH functional groups from the CDs. The incorporation of the amino- and diethylamino- CDs within the membrane selective layer improved water permeability, which was rationalised by the increased hydrophilicity and additional water channels in the modified membranes...
- Full Text:
- Authors: Mbuli, Bhekani Sydney
- Date: 2014-07-15
- Subjects: Polyamide membranes , Cyclodextrins , Water - Purification - Membrane filtration
- Type: Thesis
- Identifier: uj:11673 , http://hdl.handle.net/10210/11396
- Description: Ph.D. (Chemistry) , This thesis describes the modification of polyamide thin-film composite (TFC) membranes with amino- and diethylamino-cyclodextrins (CDs) using an interfacial polymerisation process. An in situ modification procedure was carried out using different concentrations of amino functionalized CDs (α-CDs and β-CDs) dispersed in m-phenylenediamine in water. These aqueous solutions were then reacted with trimesoyl chloride (TMC) on polyethersulphone (PES) ultrafiltration support membranes. Contact-angle measurements of the modified polyamide TFC membranes demonstrates improved hydrophilic properties due to additional –OH functional groups from the CDs. The incorporation of the amino- and diethylamino- CDs within the membrane selective layer improved water permeability, which was rationalised by the increased hydrophilicity and additional water channels in the modified membranes...
- Full Text:
Dechlorination of PCB77 using Fe/Pd bimetallic nanoparticles immobilized on microfiltration membranes
- Authors: Ndlwana, Lwazi
- Date: 2014-07-01
- Subjects: Dechlorination , Nanofiltration , Polychlorinated biphenyls - Contamination , Water - Purification - Membrane filtration
- Type: Thesis
- Identifier: uj:11643 , http://hdl.handle.net/10210/11356
- Description: M.Sc. (Nanoscience) , Polychlorinated biphenyls (PCBs) are endocrine disrupting compounds (EDCs) and are harmful to humans and the environment. These PCBs are grouped under chlorinated organic compounds (COCs). The PCBs find their way to the environment through human activity such as industrialization and farming. Such activity produces wastes and runoffs that eventually end up in the water we use for drinking, farming and sanitation. It has then become necessary for researchers to find viable methods to remove these compounds from the environment. This is because current water treatment methods are not effective in the removal of the PCBs from water. The stages in the conventional treatment methods may include sand filtration, advanced oxidative processes and coagulation among others. These methods need to be energetically eco-friendly to drive the PCB dechlorination processes. Researchers have used a variety of metallic nanoparticles including bimetallic nanoparticles for the removal of COCs from water. However, nanoparticles tend to agglomerate when not supported - leading to a decrease in their activity. Hence it has become necessary to stabilize or immobilize these nanoparticles on suitable support materials, such as, polymer solutions or solid substrates. Solid substrates including metal oxides, carbon and membranes, are currently being explored. Poly(vinylidene difluoride) microfiltration membranes are especially suitable for this function given the high porosity, chemical inertness and other outstanding physical properties. In this work, the objective was to modify commercially hydrophilized poly(vinylidine)difluoride (PVDF) membranes with poly(ethylene glycol) (PEG). PEG is a bidentate polymer with two –OH groups found on either side of the molecule. The -OH groups allows PEG binding to the PVDF polymer backbone and hence high ability to capture or chelate the metal ions followed by their reduction. Nano-zerovalent metal nanoparticles were formed from these metal ions and chelated into the PEG grafted PVDF membrane to give the composite PVDF-PEG-Fe0. Post addition of the secondary metal was then followed by the introduction of the precomposite to a Pd solution to give the final catalytic membrane (PVDF-PEG-Fe0/Pd0). The use of PEG in this system allows for an even dispersion of the nanoparticles in the composite. The resulting nanocomposite membrane was used for the dechlorination of a polychlorinated biphenyl (PCB 77). Attenuated total reflection- Fourier transform infra red spectroscopy (ATR-FTIR) showed that PEG was successfully grafted onto the PVDF backbone. Optical contact angle measurements (OCA) were taken to determine the change in hydrophilicity of the membrane upon modification. X-ray diffraction spectroscopy (XRD) proved that the Pd and Fe nanoparticles immobilized on the system were indeed zerovalent. Scanning electron microscopy (SEM) images and contact angle measurements suggested a less porous membrane and slightly decreased hydrophilicity after modification. On the SEM micrographs the nanoparticles were observed to be quite evenly distributed in the membrane. Transmission electron microscopy (TEM) showed that the nanoparticles were in the range 20-30 nm in diameter, confirming the particle size values as determined by SEM. For the preliminary dechlorination studies done under ambient conditions, two dimensional column gas chromatography- time of flight- mass spectrometry (GCxGC-TOF-MS) results showed a complete dechlorination of PCB 77. A comparative study of the bare PVDF and catalytic membranes showed a slight difference in adsorption of the total PCB 77 concentrations. The catalytic membrane maintained its activity towards the dechlorination of PCB 77 after multiple regeneration cycles.
- Full Text:
- Authors: Ndlwana, Lwazi
- Date: 2014-07-01
- Subjects: Dechlorination , Nanofiltration , Polychlorinated biphenyls - Contamination , Water - Purification - Membrane filtration
- Type: Thesis
- Identifier: uj:11643 , http://hdl.handle.net/10210/11356
- Description: M.Sc. (Nanoscience) , Polychlorinated biphenyls (PCBs) are endocrine disrupting compounds (EDCs) and are harmful to humans and the environment. These PCBs are grouped under chlorinated organic compounds (COCs). The PCBs find their way to the environment through human activity such as industrialization and farming. Such activity produces wastes and runoffs that eventually end up in the water we use for drinking, farming and sanitation. It has then become necessary for researchers to find viable methods to remove these compounds from the environment. This is because current water treatment methods are not effective in the removal of the PCBs from water. The stages in the conventional treatment methods may include sand filtration, advanced oxidative processes and coagulation among others. These methods need to be energetically eco-friendly to drive the PCB dechlorination processes. Researchers have used a variety of metallic nanoparticles including bimetallic nanoparticles for the removal of COCs from water. However, nanoparticles tend to agglomerate when not supported - leading to a decrease in their activity. Hence it has become necessary to stabilize or immobilize these nanoparticles on suitable support materials, such as, polymer solutions or solid substrates. Solid substrates including metal oxides, carbon and membranes, are currently being explored. Poly(vinylidene difluoride) microfiltration membranes are especially suitable for this function given the high porosity, chemical inertness and other outstanding physical properties. In this work, the objective was to modify commercially hydrophilized poly(vinylidine)difluoride (PVDF) membranes with poly(ethylene glycol) (PEG). PEG is a bidentate polymer with two –OH groups found on either side of the molecule. The -OH groups allows PEG binding to the PVDF polymer backbone and hence high ability to capture or chelate the metal ions followed by their reduction. Nano-zerovalent metal nanoparticles were formed from these metal ions and chelated into the PEG grafted PVDF membrane to give the composite PVDF-PEG-Fe0. Post addition of the secondary metal was then followed by the introduction of the precomposite to a Pd solution to give the final catalytic membrane (PVDF-PEG-Fe0/Pd0). The use of PEG in this system allows for an even dispersion of the nanoparticles in the composite. The resulting nanocomposite membrane was used for the dechlorination of a polychlorinated biphenyl (PCB 77). Attenuated total reflection- Fourier transform infra red spectroscopy (ATR-FTIR) showed that PEG was successfully grafted onto the PVDF backbone. Optical contact angle measurements (OCA) were taken to determine the change in hydrophilicity of the membrane upon modification. X-ray diffraction spectroscopy (XRD) proved that the Pd and Fe nanoparticles immobilized on the system were indeed zerovalent. Scanning electron microscopy (SEM) images and contact angle measurements suggested a less porous membrane and slightly decreased hydrophilicity after modification. On the SEM micrographs the nanoparticles were observed to be quite evenly distributed in the membrane. Transmission electron microscopy (TEM) showed that the nanoparticles were in the range 20-30 nm in diameter, confirming the particle size values as determined by SEM. For the preliminary dechlorination studies done under ambient conditions, two dimensional column gas chromatography- time of flight- mass spectrometry (GCxGC-TOF-MS) results showed a complete dechlorination of PCB 77. A comparative study of the bare PVDF and catalytic membranes showed a slight difference in adsorption of the total PCB 77 concentrations. The catalytic membrane maintained its activity towards the dechlorination of PCB 77 after multiple regeneration cycles.
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Design of metal organic framework anchored on graphene oxide and their incorporation into polymer membranes for water treatment
- Authors: Nqombolo, Azile
- Date: 2020
- Subjects: Metal-organic frameworks , Water - Purification - Membrane filtration
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/474220 , uj:42737
- Description: Abstract: Water polluted with heavy metals or dyes that are directly discharged from the mining, paper, textile, carpet, dyeing, and pulp industries cause problems to human beings and the ecosystem. Therefore, the polluted water must be treated before it gets discharged to the environment. Adsorption, photocatalytic degradation of dyes and membrane technology are promising techniques for the removal of these hazardous dyes. Metal organic framework materials have high surface and their functionality assist in trapping metals from water; hence they are defective adsorbents for removal of metals. Also, these porous materials have proven to be good fillers in the fabrication of ultrafiltration membranes with high performance. The thesis focused on the synthesis of various MOF-based materials and their applications in water treatment, specifically as metal adsorbents and filler materials for UF membranes. The metal adsorption studies on both acid mine drainage (AMD) and surface water (river and wastewater) for various metal ions is reported. Firstly, on the removal of Pb(II) from acid mine drainage (AMD) and secondly, on the removal of both As(V) and Cr(VI) from river water and wastewater (raw influent and effluent water samples from Daspoort treatment plant). This led to the production of several MOF materials, namely ZIF-67 (for Pb(II) in AMD and mixed metal ZIF-67/ZIF-8 (for As(V) and Cr(VI) in surface water) and a couple of novel Zr-MOF and Co-MOF bearing a newly synthesised ligand for Cd(II) and Cu(II)). All the MOFs were assessed for metal ion sequestration in water. Various parameters such as pH solution, sonication time, and mass of adsorbent were optimized in the removal of these metals. Multivariate optimization protocol was used in the removal of the three metals whilst the central composite design with 16 experiments was chosen for optimisation. The Pareto chart obtained from the resultant data gave information on the parameters that were significant in the adsorption process... , Ph.D. (Chemistry)
- Full Text:
- Authors: Nqombolo, Azile
- Date: 2020
- Subjects: Metal-organic frameworks , Water - Purification - Membrane filtration
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/474220 , uj:42737
- Description: Abstract: Water polluted with heavy metals or dyes that are directly discharged from the mining, paper, textile, carpet, dyeing, and pulp industries cause problems to human beings and the ecosystem. Therefore, the polluted water must be treated before it gets discharged to the environment. Adsorption, photocatalytic degradation of dyes and membrane technology are promising techniques for the removal of these hazardous dyes. Metal organic framework materials have high surface and their functionality assist in trapping metals from water; hence they are defective adsorbents for removal of metals. Also, these porous materials have proven to be good fillers in the fabrication of ultrafiltration membranes with high performance. The thesis focused on the synthesis of various MOF-based materials and their applications in water treatment, specifically as metal adsorbents and filler materials for UF membranes. The metal adsorption studies on both acid mine drainage (AMD) and surface water (river and wastewater) for various metal ions is reported. Firstly, on the removal of Pb(II) from acid mine drainage (AMD) and secondly, on the removal of both As(V) and Cr(VI) from river water and wastewater (raw influent and effluent water samples from Daspoort treatment plant). This led to the production of several MOF materials, namely ZIF-67 (for Pb(II) in AMD and mixed metal ZIF-67/ZIF-8 (for As(V) and Cr(VI) in surface water) and a couple of novel Zr-MOF and Co-MOF bearing a newly synthesised ligand for Cd(II) and Cu(II)). All the MOFs were assessed for metal ion sequestration in water. Various parameters such as pH solution, sonication time, and mass of adsorbent were optimized in the removal of these metals. Multivariate optimization protocol was used in the removal of the three metals whilst the central composite design with 16 experiments was chosen for optimisation. The Pareto chart obtained from the resultant data gave information on the parameters that were significant in the adsorption process... , Ph.D. (Chemistry)
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Electrospun nanofibers decorated with silver nanoparticles for fouling control
- Authors: Msomi, Phumlani Fortune
- Date: 2015-07-02
- Subjects: Antimicrobial polymers , Silver catalysts , Nanofibers , Water - Purification - Membrane filtration , Water - Purification - Microbial removal
- Type: Thesis
- Identifier: uj:13681 , http://hdl.handle.net/10210/13875
- Description: M.Tech. (Chemistry) , This work focused on the in-situ decoration of polyethersulfone (PES) nanofiber mats with silver nanoparticles (AgNPs) using an electrospinning technique. The biocidal and organic properties of the Ag decorated nanofibers were evaluated. Electrospinning of Ag decorated nanofibers was also carried out on a mixed matrix membrane support composed of nitrogen doped carbon nanotube (N-CNTs) and PES to fabricate a unique bi-faceted membrane. PES was dissolved in a solution containing silver nitrate (AgNO3) and N,Ndimethylacetamide (DMAc). The polymer solution was dissolved at 80ºC for 3 h under reflux until a yellow homogeneous solution was obtained which indicated the in-situ formation of AgNPs. The polymer solution was cooled and stored to remove air-bubbles. An ultraviolet - visible (UV – Vis) spectrometer was used to confirm the presence of AgNPs, while a Malvern nanosizer was used to estimate the size distribution of the AgNPs in the PES polymer matrix. The solution was electrospun on an aluminium (foil) collecting plate. Biocidal properties of the material were evaluated using Gram-positive (G+) Staphylococcus aureus (S. aureus) and ram-negative (G-) Escherichia coli (E. coli) by the zone inhibition method. The silver decorated polyethersulfone nanofibers showed good antibacterial activity against both G+ S. aureus and G- E. coli.
- Full Text:
- Authors: Msomi, Phumlani Fortune
- Date: 2015-07-02
- Subjects: Antimicrobial polymers , Silver catalysts , Nanofibers , Water - Purification - Membrane filtration , Water - Purification - Microbial removal
- Type: Thesis
- Identifier: uj:13681 , http://hdl.handle.net/10210/13875
- Description: M.Tech. (Chemistry) , This work focused on the in-situ decoration of polyethersulfone (PES) nanofiber mats with silver nanoparticles (AgNPs) using an electrospinning technique. The biocidal and organic properties of the Ag decorated nanofibers were evaluated. Electrospinning of Ag decorated nanofibers was also carried out on a mixed matrix membrane support composed of nitrogen doped carbon nanotube (N-CNTs) and PES to fabricate a unique bi-faceted membrane. PES was dissolved in a solution containing silver nitrate (AgNO3) and N,Ndimethylacetamide (DMAc). The polymer solution was dissolved at 80ºC for 3 h under reflux until a yellow homogeneous solution was obtained which indicated the in-situ formation of AgNPs. The polymer solution was cooled and stored to remove air-bubbles. An ultraviolet - visible (UV – Vis) spectrometer was used to confirm the presence of AgNPs, while a Malvern nanosizer was used to estimate the size distribution of the AgNPs in the PES polymer matrix. The solution was electrospun on an aluminium (foil) collecting plate. Biocidal properties of the material were evaluated using Gram-positive (G+) Staphylococcus aureus (S. aureus) and ram-negative (G-) Escherichia coli (E. coli) by the zone inhibition method. The silver decorated polyethersulfone nanofibers showed good antibacterial activity against both G+ S. aureus and G- E. coli.
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Energy generating performance of domestic wastewater fed sandwich dual-chamber microbial fuel cells
- Authors: Adeniran, Joshua Adeniyi
- Date: 2015-06-26
- Subjects: Waste products as fuel , Water - Purification - Membrane filtration , Water - Purification - Biological treatment , Sewage - Purification - Anaerobic treatment , Microbial fuel cells , Waste heat , Bioreactors
- Type: Thesis
- Identifier: uj:13627 , http://hdl.handle.net/10210/13808
- Description: M.Tech. (Civil Engineering) , This study presents work on the design and construction of three dual-chamber microbial fuel cells (MFCs) using a sandwich separator electrode assembly (SSEA) and membrane cathode assembly (MCA) for the dual purposes of energy generation from domestic wastewater and wastewater treatment. MFC1 was designed using an improvised SSEA technique (i.e. a separator electrode membrane electrode configuration, SEMEC) by gluing a sandwich of anode, membrane and a mesh current collector cathode to an anode chamber made from a polyethylene wide-mouth bottle. The reactor was filled with 1500 mL of domestic wastewater and operated on a long fed-batch mode with a residence time of 3 weeks. The reactor was inoculated with a mixed culture of bacteria present in the wastewater stream. The aim was to study the impact of wastewater COD concentration on power generation and wastewater treatment efficiency. For MFC2 and MFC 3, cathodes were constructed using the MCA technique consisting of a membrane and a mesh current collector cathode, with the anode electrode at the opposite side of stacked Perspex sections used for the anode chamber. The impact of electrode material on current production was examined in this study. For MFC2 a mesh current collector treated with polytetrafluoroethylene (PTFE) and activated carbon (AC) functioned as the cathode, while the MFC3 cathode was an uncatalyzed mesh current collector. The two reactors were both filled with 350 mL of domestic wastewater...
- Full Text:
- Authors: Adeniran, Joshua Adeniyi
- Date: 2015-06-26
- Subjects: Waste products as fuel , Water - Purification - Membrane filtration , Water - Purification - Biological treatment , Sewage - Purification - Anaerobic treatment , Microbial fuel cells , Waste heat , Bioreactors
- Type: Thesis
- Identifier: uj:13627 , http://hdl.handle.net/10210/13808
- Description: M.Tech. (Civil Engineering) , This study presents work on the design and construction of three dual-chamber microbial fuel cells (MFCs) using a sandwich separator electrode assembly (SSEA) and membrane cathode assembly (MCA) for the dual purposes of energy generation from domestic wastewater and wastewater treatment. MFC1 was designed using an improvised SSEA technique (i.e. a separator electrode membrane electrode configuration, SEMEC) by gluing a sandwich of anode, membrane and a mesh current collector cathode to an anode chamber made from a polyethylene wide-mouth bottle. The reactor was filled with 1500 mL of domestic wastewater and operated on a long fed-batch mode with a residence time of 3 weeks. The reactor was inoculated with a mixed culture of bacteria present in the wastewater stream. The aim was to study the impact of wastewater COD concentration on power generation and wastewater treatment efficiency. For MFC2 and MFC 3, cathodes were constructed using the MCA technique consisting of a membrane and a mesh current collector cathode, with the anode electrode at the opposite side of stacked Perspex sections used for the anode chamber. The impact of electrode material on current production was examined in this study. For MFC2 a mesh current collector treated with polytetrafluoroethylene (PTFE) and activated carbon (AC) functioned as the cathode, while the MFC3 cathode was an uncatalyzed mesh current collector. The two reactors were both filled with 350 mL of domestic wastewater...
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Fabrication and characterisation of highly water permeable ultrafiltration membranes as supports for forward osmosis thin film composite membranes
- Authors: Vilakati, Gcina Doctor
- Date: 2015-04-23
- Subjects: Water - Purification - Membrane filtration , Ultrafiltration , Polymeric composites
- Type: Thesis
- Identifier: uj:13564 , http://hdl.handle.net/10210/13704
- Description: Ph.D. (Chemistry) , The ultrafiltration membranes presented in this study were synthesized using the phase inversion method by casting on a nonwoven fabric. The polymer solutions were mixed with synthetic and bio additives in order to improve the resultant membrane performance. Synthetic additives (polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP)) were compared with a novel and cheap bio additive, lignin. Based on the knowledge that the additives must be soluble in water in order to increase the pore sizes of the membranes, sodium hydroxide was used to elute residual additives that remain in the membrane during coagulation. In order to trace the residual additives remaining, ATR-FTIR was used. Contact-angle analysis and water-absorption experiments were used to elucidate the hydrophilic properties of the prepared membranes. Membranes modified with lignin (Lig) were found to absorb more water (94% water uptake) when compared to the other membranes. In general, the contact angles were found to be low for membranes that were treated with NaOH. Membrane permeability followed the trend, Lig_PSf>PVP_PSf>PEG_PSf which is similar to the trend followed during water uptake. Pore size and pore distribution analysis showed that membranes modified with lignin and PVP had a narrow range (had pore sizes ranging from 10 to 24 nm) compared to that of PEG-PSf membrane (which ranged from 2.5 to 22 nm). A Robeson plot showed that Lig_PSf membranes had high separation factors regardless of the size of the solute being rejected. This study shows the possibility of using cheap and readily available additives to increase the performance of membranes......
- Full Text:
- Authors: Vilakati, Gcina Doctor
- Date: 2015-04-23
- Subjects: Water - Purification - Membrane filtration , Ultrafiltration , Polymeric composites
- Type: Thesis
- Identifier: uj:13564 , http://hdl.handle.net/10210/13704
- Description: Ph.D. (Chemistry) , The ultrafiltration membranes presented in this study were synthesized using the phase inversion method by casting on a nonwoven fabric. The polymer solutions were mixed with synthetic and bio additives in order to improve the resultant membrane performance. Synthetic additives (polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP)) were compared with a novel and cheap bio additive, lignin. Based on the knowledge that the additives must be soluble in water in order to increase the pore sizes of the membranes, sodium hydroxide was used to elute residual additives that remain in the membrane during coagulation. In order to trace the residual additives remaining, ATR-FTIR was used. Contact-angle analysis and water-absorption experiments were used to elucidate the hydrophilic properties of the prepared membranes. Membranes modified with lignin (Lig) were found to absorb more water (94% water uptake) when compared to the other membranes. In general, the contact angles were found to be low for membranes that were treated with NaOH. Membrane permeability followed the trend, Lig_PSf>PVP_PSf>PEG_PSf which is similar to the trend followed during water uptake. Pore size and pore distribution analysis showed that membranes modified with lignin and PVP had a narrow range (had pore sizes ranging from 10 to 24 nm) compared to that of PEG-PSf membrane (which ranged from 2.5 to 22 nm). A Robeson plot showed that Lig_PSf membranes had high separation factors regardless of the size of the solute being rejected. This study shows the possibility of using cheap and readily available additives to increase the performance of membranes......
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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)
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- 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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Fabrication of positively charged membranes with high antifouling characteristics via graphene oxide incorporated pes/pei/agno3 for the removal of heavy metals and dyes from wastewater
- Authors: Nonso, Chukwuati C
- Date: 2019
- Subjects: Membrane filters , Water - Purification - Membrane filtration , Sewage - Purification
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/400955 , uj:33487
- Description: Abstract : A series of ultrafiltration (UF) membranes based on the hydrophobic polyvinylidene fluoride (PVDF) and hydrophilic polyethersulfone (PES) containing new nanofillers based on graphene oxide (GO) were fabricated and their performance assessed against both organic dye and metal ion rejection. The incorporated nanofillers were GO nanosheets coated with hyperbranched polyethyleneimine (HPEI, HPEI@GO) in the first instance and its composite with silver nanoparticles (AgNPs, AgNPs/HPEI@GO). Different weight concentrations (wt%) of these modifiers were incorporated into PES or PVDF polymers matrix followed by fabrication of composite membranes through phase inversion method. The prepared materials, i.e. GO nanosheets, the various GO composite and the fabricated membranes were characterised using various physicochemical techniques such as Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) Thermal Gravimetric Analysis (TGA), Braunuer Emmet Teller (BET), X-ray diffraction (XRD), Raman, Atomic Force Microscopy (AFM), water uptake, contact angle (CA) as well as membranes performance through pure water flux, flux recovery and rejection capacities. Raman spectroscopy was primarily used to confirm the nature of GO while FTIR was utilised to confirm the presence of the HPEI polymer deposited on GO nanosheets. For instance, the coating of the HPEI on the surface of GO nanosheets via grafting of HPEI on the surface of GO nanosheets was confirmed by the presence of the CN groups and cationic NH groups on the vibration pattern of HPEI@GO composite. On the other hand, the SEM-EDs analyses revealed the elemental composition of the synthesised GO nanosheets and GO composite to be Carbon, Oxygen, Nitrogen, and Silver affirming the FTIR results. The pure water flux of the unmodified PES membranes was improved from 35±0.52 L/m2h to the range of 77±0.92 to120±1.44 L/m2h (which is 114% to 243%) for the series of GO@PES membranes compared to the baseline membranes. Thus, in the series of HPEI/GO@PES containing membranes, the flux improved to the range of 55±0.82 to vi 89±1.33 L/m2h (which is 57% to 171% increase) and the series of AgNPs/HPEI/GO@PES membranes were improved to the range of 40±0.60 to 50±0.75 L/m2h (which is 14% to 66% increase). This observed improve could be attributed to the incorporated charge and oxygen functionalities. The Flux recovery ratio (FRR) of the synthesised membranes were also improved from 45% for the unmodified PES membranes to the range of 80% to 93% for the series of GO@PES membranes, 74% to 78% for the series of HPEI/GO@PES and 74% to 75% for the series of AgNPs/HPEI/GO@PES membranes due to less attachment of the bovine serum albumin (BSA) solution on the membranes surface and pores. The fouling propensity of PES membranes was further evaluated using organic pollutants such as MO, MB, AR, CR, and BPA after a prolong filtration and washing. The FRR of the unmodified PES membranes was 42%. This was improved to the range of 80% to 92% for the series of GO@PES membranes, 76% to 78% for the series of HPEI/GO@PES membranes and 71% to 73% for the series of AgNPs/HPEI/GO@PES membranes due to less attachment of dye molecules on the membranes surface and pores, indicating that the modified PES membranes had improved antifouling properties. The cleaned membranes were further subjected to SEM-EDS surface morphology and elemental composition analysis to ascertain the degree of foulants attachment on the membrane’s surfaces i.e. a post-mortem of the membranes was undertaken. This confirmed that the unmodified PES membranes were more fouled. The observed improvement in the antifouling properties of the modified membranes could be attributed to the presence of hydrophilic functionalities from the incorporated nanofillers. The series of the positively charged HPEI/GO@PES membranes at pH 6.8 and 8.0 showed a progressive increase in rejection capacity with increase in weight concentration of the GO composite in the PES matrix. At pH 6.8, the rejection capacity was enhanced from 90% to 95% for Pb2+, 77% to 85% of Cr6+ and 69% to 81% of Cd2+ which were higher compared to the rejection capacity of the unmodified PES membranes. Similar trend in rejection pattern was observed at pH 8.0 for the same series of membranes. For the series of GO@PES, and AgNPs/HPEI/GO@PES membranes, the ability of these membranes to reject these metal ions at pH 6.0, 6.8, vii and 8.0 declines as the weight concentration of the GO nanosheets and GO composite increased in the PES matrix. This could be due to increased membranes micropores and macro-voids (SEM images). The positively charged PES membranes displayed high removal capacity of above 90% for small positively charged methylene blue dye and less rejection capacity of 73% and less for a bigger negatively charged amaranth dye. The difference in the rejection capacity of the synthesised membranes could be attributed to the chemical nature of the membranes surface in contact with the pollutants, molecular weight cut off of the membranes films as well as the surface charge of the pollutants to be rejected. As a result to which the positively charged membranes had high removal efficiency for the methylene blue dye. A similarly improve in rejection pattern of pollutants were also observed for the graphene-based nanomaterials modified PVDF membranes. The observed significant improvement in the modified membranes can be attributed to the presence of oxygenated and charged functionalities on the surfaces of the synthesised graphenebased nanofillers compared to unmodified membranes... , M.Sc. (Chemistry)
- Full Text:
- Authors: Nonso, Chukwuati C
- Date: 2019
- Subjects: Membrane filters , Water - Purification - Membrane filtration , Sewage - Purification
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/400955 , uj:33487
- Description: Abstract : A series of ultrafiltration (UF) membranes based on the hydrophobic polyvinylidene fluoride (PVDF) and hydrophilic polyethersulfone (PES) containing new nanofillers based on graphene oxide (GO) were fabricated and their performance assessed against both organic dye and metal ion rejection. The incorporated nanofillers were GO nanosheets coated with hyperbranched polyethyleneimine (HPEI, HPEI@GO) in the first instance and its composite with silver nanoparticles (AgNPs, AgNPs/HPEI@GO). Different weight concentrations (wt%) of these modifiers were incorporated into PES or PVDF polymers matrix followed by fabrication of composite membranes through phase inversion method. The prepared materials, i.e. GO nanosheets, the various GO composite and the fabricated membranes were characterised using various physicochemical techniques such as Fourier Transform Infrared (FTIR), Transmission Electron Microscope (TEM), Scanning Electron Microscopy with Energy Dispersive Spectroscopy (SEM-EDS) Thermal Gravimetric Analysis (TGA), Braunuer Emmet Teller (BET), X-ray diffraction (XRD), Raman, Atomic Force Microscopy (AFM), water uptake, contact angle (CA) as well as membranes performance through pure water flux, flux recovery and rejection capacities. Raman spectroscopy was primarily used to confirm the nature of GO while FTIR was utilised to confirm the presence of the HPEI polymer deposited on GO nanosheets. For instance, the coating of the HPEI on the surface of GO nanosheets via grafting of HPEI on the surface of GO nanosheets was confirmed by the presence of the CN groups and cationic NH groups on the vibration pattern of HPEI@GO composite. On the other hand, the SEM-EDs analyses revealed the elemental composition of the synthesised GO nanosheets and GO composite to be Carbon, Oxygen, Nitrogen, and Silver affirming the FTIR results. The pure water flux of the unmodified PES membranes was improved from 35±0.52 L/m2h to the range of 77±0.92 to120±1.44 L/m2h (which is 114% to 243%) for the series of GO@PES membranes compared to the baseline membranes. Thus, in the series of HPEI/GO@PES containing membranes, the flux improved to the range of 55±0.82 to vi 89±1.33 L/m2h (which is 57% to 171% increase) and the series of AgNPs/HPEI/GO@PES membranes were improved to the range of 40±0.60 to 50±0.75 L/m2h (which is 14% to 66% increase). This observed improve could be attributed to the incorporated charge and oxygen functionalities. The Flux recovery ratio (FRR) of the synthesised membranes were also improved from 45% for the unmodified PES membranes to the range of 80% to 93% for the series of GO@PES membranes, 74% to 78% for the series of HPEI/GO@PES and 74% to 75% for the series of AgNPs/HPEI/GO@PES membranes due to less attachment of the bovine serum albumin (BSA) solution on the membranes surface and pores. The fouling propensity of PES membranes was further evaluated using organic pollutants such as MO, MB, AR, CR, and BPA after a prolong filtration and washing. The FRR of the unmodified PES membranes was 42%. This was improved to the range of 80% to 92% for the series of GO@PES membranes, 76% to 78% for the series of HPEI/GO@PES membranes and 71% to 73% for the series of AgNPs/HPEI/GO@PES membranes due to less attachment of dye molecules on the membranes surface and pores, indicating that the modified PES membranes had improved antifouling properties. The cleaned membranes were further subjected to SEM-EDS surface morphology and elemental composition analysis to ascertain the degree of foulants attachment on the membrane’s surfaces i.e. a post-mortem of the membranes was undertaken. This confirmed that the unmodified PES membranes were more fouled. The observed improvement in the antifouling properties of the modified membranes could be attributed to the presence of hydrophilic functionalities from the incorporated nanofillers. The series of the positively charged HPEI/GO@PES membranes at pH 6.8 and 8.0 showed a progressive increase in rejection capacity with increase in weight concentration of the GO composite in the PES matrix. At pH 6.8, the rejection capacity was enhanced from 90% to 95% for Pb2+, 77% to 85% of Cr6+ and 69% to 81% of Cd2+ which were higher compared to the rejection capacity of the unmodified PES membranes. Similar trend in rejection pattern was observed at pH 8.0 for the same series of membranes. For the series of GO@PES, and AgNPs/HPEI/GO@PES membranes, the ability of these membranes to reject these metal ions at pH 6.0, 6.8, vii and 8.0 declines as the weight concentration of the GO nanosheets and GO composite increased in the PES matrix. This could be due to increased membranes micropores and macro-voids (SEM images). The positively charged PES membranes displayed high removal capacity of above 90% for small positively charged methylene blue dye and less rejection capacity of 73% and less for a bigger negatively charged amaranth dye. The difference in the rejection capacity of the synthesised membranes could be attributed to the chemical nature of the membranes surface in contact with the pollutants, molecular weight cut off of the membranes films as well as the surface charge of the pollutants to be rejected. As a result to which the positively charged membranes had high removal efficiency for the methylene blue dye. A similarly improve in rejection pattern of pollutants were also observed for the graphene-based nanomaterials modified PVDF membranes. The observed significant improvement in the modified membranes can be attributed to the presence of oxygenated and charged functionalities on the surfaces of the synthesised graphenebased nanofillers compared to unmodified membranes... , M.Sc. (Chemistry)
- Full Text:
Fabrication, simulation and techno-economic evaluation of thin film nanocomposite membrane for acid mine drainage treatment
- Ramokgopa, Selaelo Kholofelo
- Authors: Ramokgopa, Selaelo Kholofelo
- Date: 2020
- Subjects: Water - Purification - Membrane filtration , Acid mine drainage - Purification , Nanocomposites (Materials) , Thin films
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/480084 , uj:43447
- Description: Abstract: Thin Film Composite (TFC) membrane technology has been applied in the removal of various pollutants from wastewater. TFC membranes have small pore sizes which enable the rejection of multivalent ions such as those found in Acid Mine Drainage (AMD). Also, nanoparticles with desirable properties have been added to TFC membranes to form Thin Film Nanocomposite (TFN) membranes with potentially enhanced properties. A great opportunity is provided for novel and sustainable development of TFN membranes with Carbon Nanotube (CNTs) for the treatment of AMD. CNT-Infused TFN membranes were synthesized to investigate the feasibility for use in synthetic AMD treatment. Flux and rejection under various operating conditions were measured. The addition of CNTs improved flux by up to 50% and reduced heavy metal concentration in AMD up to 95%. Furthermore, rejection followed the sequence Mg2+>Fe3+>Al3+. Design of Experiments (DOE) was used to determine the effects of process parameters (heavy metal concentration, pressure and MWCNT loading) on process optimisation and semi-empirical modelling techniques were conducted on the experimental data. Response Surface Methodology (RSM) was used to evaluate model outputs and Analysis of variance (ANOVA) was used for model validation. Iron concentration, pressure and CNT loading were found to have the most significance on the process followed by magnesium concentration and aluminium concentration according to RSM results... , M.Tech. (Chemical Engineering)
- Full Text:
- Authors: Ramokgopa, Selaelo Kholofelo
- Date: 2020
- Subjects: Water - Purification - Membrane filtration , Acid mine drainage - Purification , Nanocomposites (Materials) , Thin films
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/480084 , uj:43447
- Description: Abstract: Thin Film Composite (TFC) membrane technology has been applied in the removal of various pollutants from wastewater. TFC membranes have small pore sizes which enable the rejection of multivalent ions such as those found in Acid Mine Drainage (AMD). Also, nanoparticles with desirable properties have been added to TFC membranes to form Thin Film Nanocomposite (TFN) membranes with potentially enhanced properties. A great opportunity is provided for novel and sustainable development of TFN membranes with Carbon Nanotube (CNTs) for the treatment of AMD. CNT-Infused TFN membranes were synthesized to investigate the feasibility for use in synthetic AMD treatment. Flux and rejection under various operating conditions were measured. The addition of CNTs improved flux by up to 50% and reduced heavy metal concentration in AMD up to 95%. Furthermore, rejection followed the sequence Mg2+>Fe3+>Al3+. Design of Experiments (DOE) was used to determine the effects of process parameters (heavy metal concentration, pressure and MWCNT loading) on process optimisation and semi-empirical modelling techniques were conducted on the experimental data. Response Surface Methodology (RSM) was used to evaluate model outputs and Analysis of variance (ANOVA) was used for model validation. Iron concentration, pressure and CNT loading were found to have the most significance on the process followed by magnesium concentration and aluminium concentration according to RSM results... , M.Tech. (Chemical Engineering)
- Full Text:
Fouling of nanofiltration membranes : mechanisms and implications for trace organic rejection
- Authors: Mahlangu, Oranso Themba
- Date: 2015
- Subjects: Fouling , Membrane filters , Membrane separation , Water - Purification - Membrane filtration , Water - Purification - Organic compounds removal
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/58774 , uj:16489
- Description: Abstract: Please refer to full text to view abstract , Ph.D. (Chemistry)
- Full Text:
- Authors: Mahlangu, Oranso Themba
- Date: 2015
- Subjects: Fouling , Membrane filters , Membrane separation , Water - Purification - Membrane filtration , Water - Purification - Organic compounds removal
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/58774 , uj:16489
- Description: Abstract: Please refer to full text to view abstract , Ph.D. (Chemistry)
- Full Text:
Fundamental mechanisms of forward osmosis membrane fouling during seawater desalination and wastewater reclamation
- Authors: Motsa, Mxolisi Machawe
- Date: 2015
- Subjects: Saline water conversion , Saline water conversion - Reverse osmosis process , Water - Purification - Membrane filtration , Seawater - Distillation
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/58793 , uj:16492
- Description: Abstract: Please refer to full text to view abstract , Ph.D. (Chemistry)
- Full Text:
- Authors: Motsa, Mxolisi Machawe
- Date: 2015
- Subjects: Saline water conversion , Saline water conversion - Reverse osmosis process , Water - Purification - Membrane filtration , Seawater - Distillation
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/58793 , uj:16492
- Description: Abstract: Please refer to full text to view abstract , Ph.D. (Chemistry)
- Full Text:
Graphene based molecularly imprinted polymer composites and composite imprinted ultrafiltration membrane for water treatment
- Authors: Kibechu, Rose Waithiegeni
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Ultrafiltration , Polymeric composites , Graphene
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/124901 , uj:20972
- Description: Abstract: Membranes for water treatment face a major problem of fouling. One of the solutions to reduce fouling propensity in membranes is the addition of hydrophilic additives during membrane preparation. In this study, a significant enhancement of hydrophilicity, flux and rejection of Na2SO4 by a modified polysulfone membrane was observed. The membrane was prepared using graphene oxide (GO) as a hydrophilic additive followed by surface modification through imprinting on Graphene oxide-polysulfone (GO-Psf) mixed composite membranes. GO was synthesized through oxidation and exfoliation of graphite. The GO-Psf composite membrane was prepared through a phase inversion process of a mixture of GO and polysulfone (Psf) in N-methylpyrrolidone (NMP). Imprinting on the surface of composite membrane was achieved through a free radical polymerization. Characterization of the GO and the prepared membranes was achieved using Fourier-transform spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA), contact angle, scanning electron microscope (SEM) and transmission electron microscope (TEM). FT-IR of the composite imprinted membranes (CIMs) showed new peaks at 935 cm-1 and 1638 cm-1 indicating the success of surface imprinting. Raman spectroscopy was used to confirm the presence of GO in the modified membrane. The CIMs showed improvement in flux from 8.56 LM-2h-1 of neat polysulfone membrane, to 15.3 LM-2h-1 in the CIM. Similarly, rejection of Na2SO4 salt rejection also increased from 57.2±4.2 % of polysulfone membrane to 76±4.5 % in CIMs. The surface modified membranes also showed improvement of surface hydrophilicity; the contact angle measurements for the neat polysulfone membrane was measured to be 72±2.7 % compared to... , Ph.D. (Chemistry)
- Full Text:
- Authors: Kibechu, Rose Waithiegeni
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Ultrafiltration , Polymeric composites , Graphene
- Language: English
- Type: Doctoral (Thesis)
- Identifier: http://hdl.handle.net/10210/124901 , uj:20972
- Description: Abstract: Membranes for water treatment face a major problem of fouling. One of the solutions to reduce fouling propensity in membranes is the addition of hydrophilic additives during membrane preparation. In this study, a significant enhancement of hydrophilicity, flux and rejection of Na2SO4 by a modified polysulfone membrane was observed. The membrane was prepared using graphene oxide (GO) as a hydrophilic additive followed by surface modification through imprinting on Graphene oxide-polysulfone (GO-Psf) mixed composite membranes. GO was synthesized through oxidation and exfoliation of graphite. The GO-Psf composite membrane was prepared through a phase inversion process of a mixture of GO and polysulfone (Psf) in N-methylpyrrolidone (NMP). Imprinting on the surface of composite membrane was achieved through a free radical polymerization. Characterization of the GO and the prepared membranes was achieved using Fourier-transform spectroscopy (FT-IR), Raman spectroscopy, thermogravimetric analysis (TGA), contact angle, scanning electron microscope (SEM) and transmission electron microscope (TEM). FT-IR of the composite imprinted membranes (CIMs) showed new peaks at 935 cm-1 and 1638 cm-1 indicating the success of surface imprinting. Raman spectroscopy was used to confirm the presence of GO in the modified membrane. The CIMs showed improvement in flux from 8.56 LM-2h-1 of neat polysulfone membrane, to 15.3 LM-2h-1 in the CIM. Similarly, rejection of Na2SO4 salt rejection also increased from 57.2±4.2 % of polysulfone membrane to 76±4.5 % in CIMs. The surface modified membranes also showed improvement of surface hydrophilicity; the contact angle measurements for the neat polysulfone membrane was measured to be 72±2.7 % compared to... , Ph.D. (Chemistry)
- Full Text:
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)
- Full Text:
How to measure specific deposit washout and backwash efficiency of granular filters
- Van Staden, S. J., Haarhoff, J.
- Authors: Van Staden, S. J. , Haarhoff, J.
- Date: 2010
- Subjects: Water treatment plants , Carbon, Activated , Water - Purification - Membrane filtration
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/16407 , uj:15770 , Van Staden, S.J., & Haarhoff, J. 2010. How to measure specific deposit washout and backwash efficiency of granular filters. In: Proceedings of the IWA Young Water Professionals Conference, 5-7 July 2010, Sydney, Australia, pC2, 11p.
- Description: Abstract: Practical experience shows that water treatment filters develop problems over time due to the routine running of the filter, including backwashing. There are difficulties in maintaining filters in good condition, given the eutrophic state of many South African raw waters, high water temperatures and the development of difficult-to-remove biofilm as a result. Such difficulties are often related to deposits accumulated on the filter media and it is, therefore, expected that the backwash system should be good enough to ensure that the filter is kept clean in the long run. This paper deals with a fairly simple operational option to significantly improve backwash efficiency at treatment plants where air and water are used consecutively. The paper describes methods used and typical results obtained in the testing of the quantitative benefits of multiple wash cycles. Multiple washing shows great promise for improving backwash efficiency, with an average of an additional 40% to 50% of the solids that would have been washed out with a single wash, removed by a second wash. Furthermore, third and even fourth washes continue to remove additional dirt from the filter. Multiple washing, therefore, may be a useful tool for the effective rehabilitation of a filter, as well as for routine operation procedures.
- Full Text:
- Authors: Van Staden, S. J. , Haarhoff, J.
- Date: 2010
- Subjects: Water treatment plants , Carbon, Activated , Water - Purification - Membrane filtration
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/16407 , uj:15770 , Van Staden, S.J., & Haarhoff, J. 2010. How to measure specific deposit washout and backwash efficiency of granular filters. In: Proceedings of the IWA Young Water Professionals Conference, 5-7 July 2010, Sydney, Australia, pC2, 11p.
- Description: Abstract: Practical experience shows that water treatment filters develop problems over time due to the routine running of the filter, including backwashing. There are difficulties in maintaining filters in good condition, given the eutrophic state of many South African raw waters, high water temperatures and the development of difficult-to-remove biofilm as a result. Such difficulties are often related to deposits accumulated on the filter media and it is, therefore, expected that the backwash system should be good enough to ensure that the filter is kept clean in the long run. This paper deals with a fairly simple operational option to significantly improve backwash efficiency at treatment plants where air and water are used consecutively. The paper describes methods used and typical results obtained in the testing of the quantitative benefits of multiple wash cycles. Multiple washing shows great promise for improving backwash efficiency, with an average of an additional 40% to 50% of the solids that would have been washed out with a single wash, removed by a second wash. Furthermore, third and even fourth washes continue to remove additional dirt from the filter. Multiple washing, therefore, may be a useful tool for the effective rehabilitation of a filter, as well as for routine operation procedures.
- Full Text:
How to measure specific deposit washout and backwash efficiency of granular filters
- Van Staden, S.J., Haarhoff, J.
- Authors: Van Staden, S.J. , Haarhoff, J.
- Date: 2011
- Subjects: Water - Purification - Membrane filtration , Water treatment plants , Carbon, Activated
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/16971 , uj:15830 , Van Staden, S.J. & Haarhoff, J. (2011) How to measure the specific deposit washout and backwash efficiency of granular filters. Water Practice and Technology 6 (1) DOI:10.2166/WPT. 2011.014.
- Description: Abstract Practical experience shows that water treatment filters develop problems over time due to the routine running of the filter, including backwashing. There are difficulties in maintaining filters in good condition, given the eutrophic state of many South African raw waters, high water temperatures and the development of difficult-to-remove biofilm as a result. Such difficulties are often related to deposits accumulated on the filter media and it is, therefore, expected that the backwash system should be good enough to ensure that the filter is kept clean in the long run. This paper deals with a fairly simple operational option to significantly improve backwash efficiency at treatment plants where air and water are used consecutively. The paper describes methods used and typical results obtained in the testing of the quantitative benefits of multiple wash cycles. Multiple washing shows great promise for improving backwash efficiency, with an average of an additional 40% to 50% of the solids that would have been washed out with a single wash, removed by a second wash. Furthermore, third and even fourth washes continue to remove additional dirt from the filter. Multiple washing, therefore, may be a useful tool for the effective rehabilitation of a filter, as well as for routine operation procedures.
- Full Text:
- Authors: Van Staden, S.J. , Haarhoff, J.
- Date: 2011
- Subjects: Water - Purification - Membrane filtration , Water treatment plants , Carbon, Activated
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/16971 , uj:15830 , Van Staden, S.J. & Haarhoff, J. (2011) How to measure the specific deposit washout and backwash efficiency of granular filters. Water Practice and Technology 6 (1) DOI:10.2166/WPT. 2011.014.
- Description: Abstract Practical experience shows that water treatment filters develop problems over time due to the routine running of the filter, including backwashing. There are difficulties in maintaining filters in good condition, given the eutrophic state of many South African raw waters, high water temperatures and the development of difficult-to-remove biofilm as a result. Such difficulties are often related to deposits accumulated on the filter media and it is, therefore, expected that the backwash system should be good enough to ensure that the filter is kept clean in the long run. This paper deals with a fairly simple operational option to significantly improve backwash efficiency at treatment plants where air and water are used consecutively. The paper describes methods used and typical results obtained in the testing of the quantitative benefits of multiple wash cycles. Multiple washing shows great promise for improving backwash efficiency, with an average of an additional 40% to 50% of the solids that would have been washed out with a single wash, removed by a second wash. Furthermore, third and even fourth washes continue to remove additional dirt from the filter. Multiple washing, therefore, may be a useful tool for the effective rehabilitation of a filter, as well as for routine operation procedures.
- Full Text:
Modification of polyethersulfone by grafting acrylic-acid based monomers for improved hydrophilicity and pH-responsive properties of membranes
- Authors: Kgatle, Masaku
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Membrane filters , Nanofiltration , Graft copolymers , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124976 , uj:20981
- Description: Abstract: The quality of drinking water is continuously deteriorating due to pollutants that end up in water arising from a variety of industries. These pollutants reduce the value of water thereby posing risks to people’s health and the environment. Thus, there is a need to develop techniques that will be effective in wastewater treatment to obtain potable water. Membrane technology has increasingly become the most reliable, applicable and cost-effective technique for drinking water treatment solution. However, membrane fouling has been identified as the major obstacle to the applicability of this technique. In order to alleviate this issue, many studies have proved that improving the hydrophilicity of a membrane surface is significant. In this study, acrylic acid (AA)-based monomers (acrylic acid (AA), methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA)) were graft-polymerized onto hydrophobic polyethersulfone (PES) using benzoyl peroxide (BPO) as the chemical initiator for the development of membranes with pH-responsive and antifouling properties. The confirmation of successful grafting was done using nuclear magnetic resonance (NMR) and fourier transform infrared (FTIR) spectroscopies. Flat-sheet pristine and grafted PES membranes were prepared by phase inversion via immersion precipitation technique. The morphology of the membranes was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Furthermore, membrane hydrophilicity and performance were investigated using contact angle measurements and dead-end filtration (pure water flux, bovine serum albumin (BSA) rejection and fouling analysis). The SEM analysis showed an increase in the pore size of the PES-g-PAA, PES-g-PMAA and PES-g-PEGDMA membranes in comparison with the pristine PES membrane. The contact angle measurements indicated significant increases in the hydrophilicities with chemical grafting of the AA-based monomers onto PES. The pH-responsive tests proved that the grafted PES membranes all... , M.Sc. (Chemistry)
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- Authors: Kgatle, Masaku
- Date: 2016
- Subjects: Water - Purification - Membrane filtration , Membrane filters , Nanofiltration , Graft copolymers , Polymeric composites
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/124976 , uj:20981
- Description: Abstract: The quality of drinking water is continuously deteriorating due to pollutants that end up in water arising from a variety of industries. These pollutants reduce the value of water thereby posing risks to people’s health and the environment. Thus, there is a need to develop techniques that will be effective in wastewater treatment to obtain potable water. Membrane technology has increasingly become the most reliable, applicable and cost-effective technique for drinking water treatment solution. However, membrane fouling has been identified as the major obstacle to the applicability of this technique. In order to alleviate this issue, many studies have proved that improving the hydrophilicity of a membrane surface is significant. In this study, acrylic acid (AA)-based monomers (acrylic acid (AA), methacrylic acid (MAA) and ethylene glycol dimethacrylate (EGDMA)) were graft-polymerized onto hydrophobic polyethersulfone (PES) using benzoyl peroxide (BPO) as the chemical initiator for the development of membranes with pH-responsive and antifouling properties. The confirmation of successful grafting was done using nuclear magnetic resonance (NMR) and fourier transform infrared (FTIR) spectroscopies. Flat-sheet pristine and grafted PES membranes were prepared by phase inversion via immersion precipitation technique. The morphology of the membranes was studied using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Furthermore, membrane hydrophilicity and performance were investigated using contact angle measurements and dead-end filtration (pure water flux, bovine serum albumin (BSA) rejection and fouling analysis). The SEM analysis showed an increase in the pore size of the PES-g-PAA, PES-g-PMAA and PES-g-PEGDMA membranes in comparison with the pristine PES membrane. The contact angle measurements indicated significant increases in the hydrophilicities with chemical grafting of the AA-based monomers onto PES. The pH-responsive tests proved that the grafted PES membranes all... , M.Sc. (Chemistry)
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Nanostructured membranes embedded with hyperbranched polyethyleneimine (HPEI) hosts and titanium dioxide (TiO2) nanoparticles for water purification
- Authors: Mathumba, Penny
- Date: 2016
- Subjects: Water - Purification , Water - Purification - Membrane filtration , Titanium dioxide , Nanotechnology
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84654 , uj:19247
- Description: Abstract: Water scarcity is a huge challenge throughout the world. The capacity of water in South African water systems will decrease dramatically in the next 10 years. Moreover the removal of pollutants from industrial and municipal water has become a challenge for water treatment industries. In particular, the textile industry consumes large volumes of water during dyeing processes. Thus textile industries are regarded as major polluters in the world. Azo dyes (e.g. Methyl Orange and Methyl Blue) constitute about 70% of the dyes used in the textile industry. The water discharged from textile industries is highly coloured and contains compounds that are complex in nature. Coloured water prevents the penetration of light into rivers and lakes thus affecting the process of photosynthesis and this affects the natural flora and fauna. Moreover, the improper discharge of untreated coloured dye effluent into the environment has resulted in numerous public protests. Methyl orange has been reported to be toxic and mutagenic to animals. Moreover, most of these dyes are also not effectively removed by the use of conventional biological treatment processes since they are non-biodegradable... , M.Sc.
- Full Text:
- Authors: Mathumba, Penny
- Date: 2016
- Subjects: Water - Purification , Water - Purification - Membrane filtration , Titanium dioxide , Nanotechnology
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/84654 , uj:19247
- Description: Abstract: Water scarcity is a huge challenge throughout the world. The capacity of water in South African water systems will decrease dramatically in the next 10 years. Moreover the removal of pollutants from industrial and municipal water has become a challenge for water treatment industries. In particular, the textile industry consumes large volumes of water during dyeing processes. Thus textile industries are regarded as major polluters in the world. Azo dyes (e.g. Methyl Orange and Methyl Blue) constitute about 70% of the dyes used in the textile industry. The water discharged from textile industries is highly coloured and contains compounds that are complex in nature. Coloured water prevents the penetration of light into rivers and lakes thus affecting the process of photosynthesis and this affects the natural flora and fauna. Moreover, the improper discharge of untreated coloured dye effluent into the environment has resulted in numerous public protests. Methyl orange has been reported to be toxic and mutagenic to animals. Moreover, most of these dyes are also not effectively removed by the use of conventional biological treatment processes since they are non-biodegradable... , M.Sc.
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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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Parametric study and economic evaluation of a simulated biogas upgrading plant
- Authors: Masebinu, Samson Oluwasegun
- Date: 2015-06-25
- Subjects: Sewage disposal plants - Biodegradation , Sewage disposal plants - Energy conservation , Sewage - Purification - Anaerobic treatment , Water - Purification - Biological treatment , Water - Purification - Membrane filtration , Sewage - Purification - Filtration
- Type: Thesis
- Identifier: uj:13616 , http://hdl.handle.net/10210/13799
- Description: M. Tech. (Chemical Engineering) , The usual target of an upgrading process using membrane is to produce a retentate stream, the product, with high CH4 concentration. This work presents a simulation of two possible membrane configurations, single stage without recycle (SSWR) and double stage with permeate recycle (DSPR), of an existing operational biogas upgrading plant. The simulation was conducted using ChemCAD and AlmeeSoft gas permeation software to investigate the performance of the configurations on product purity, recovery and required compressor power with a view to determine the optimal operational conditions for maximising the concentration of CH4 and its recovery. Thereafter, an economic assessment on the optimal configuration was conducted to determine the gas processing cost (GPC), the profitability of producing biomethane and cost-benefit of utilising biomethane as a vehicular fuel. The simulation was validated against plant data with a maximum percentage error of 2.64%. Increasing CO2 in feed reduced product recovery and purity. Increasing feed pressure and selectivity increased product recovery and purity up to the pressure limit of the membrane module. Increasing feed flow rate increased product recovery but reduces purity. In both configurations, increasing CO2 in the feed and increasing feed pressure increased the GPC. However, increasing feed flow rate reduced the GPC. The overall performance of DSPR configuration was much higher due to increased trans-membrane area available for separation. At optimal conditions, a product purity of 91% and 96% CH4 recovery was achieved from the initial plant result of 87.2% product purity and 91.16% CH4 recovery. The total compression duty was 141 kW. The GPC was $0.46/m3 of biomethane. The cumulative discounted NPV, IRR and BCR for producing biomethane was R15,240,343, 22.41% and 2.05 respectively, with a break-even in the 5th year after plant start-up considering a prime lending rate at 9%. Using CBG instead of gasoline saves 34% of annual fuel cost with a payback period of one year and three months for the cost of retrofitting the vehicle.
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- Authors: Masebinu, Samson Oluwasegun
- Date: 2015-06-25
- Subjects: Sewage disposal plants - Biodegradation , Sewage disposal plants - Energy conservation , Sewage - Purification - Anaerobic treatment , Water - Purification - Biological treatment , Water - Purification - Membrane filtration , Sewage - Purification - Filtration
- Type: Thesis
- Identifier: uj:13616 , http://hdl.handle.net/10210/13799
- Description: M. Tech. (Chemical Engineering) , The usual target of an upgrading process using membrane is to produce a retentate stream, the product, with high CH4 concentration. This work presents a simulation of two possible membrane configurations, single stage without recycle (SSWR) and double stage with permeate recycle (DSPR), of an existing operational biogas upgrading plant. The simulation was conducted using ChemCAD and AlmeeSoft gas permeation software to investigate the performance of the configurations on product purity, recovery and required compressor power with a view to determine the optimal operational conditions for maximising the concentration of CH4 and its recovery. Thereafter, an economic assessment on the optimal configuration was conducted to determine the gas processing cost (GPC), the profitability of producing biomethane and cost-benefit of utilising biomethane as a vehicular fuel. The simulation was validated against plant data with a maximum percentage error of 2.64%. Increasing CO2 in feed reduced product recovery and purity. Increasing feed pressure and selectivity increased product recovery and purity up to the pressure limit of the membrane module. Increasing feed flow rate increased product recovery but reduces purity. In both configurations, increasing CO2 in the feed and increasing feed pressure increased the GPC. However, increasing feed flow rate reduced the GPC. The overall performance of DSPR configuration was much higher due to increased trans-membrane area available for separation. At optimal conditions, a product purity of 91% and 96% CH4 recovery was achieved from the initial plant result of 87.2% product purity and 91.16% CH4 recovery. The total compression duty was 141 kW. The GPC was $0.46/m3 of biomethane. The cumulative discounted NPV, IRR and BCR for producing biomethane was R15,240,343, 22.41% and 2.05 respectively, with a break-even in the 5th year after plant start-up considering a prime lending rate at 9%. Using CBG instead of gasoline saves 34% of annual fuel cost with a payback period of one year and three months for the cost of retrofitting the vehicle.
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