Bioenergy; a substitute and cleaner energy option
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Anthropogenic , Biomass , Global warming
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250343 , uj:26085 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Bioenergy; a substitute and cleaner energy option. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The early man used energy in the form of food as power source for himself. Man further used energy from the sun for warmth and drying processes. With the advent of civilization and advancement, even more energy was needed to meet up with everyday industrialization demands. This led to a persistent pursuit and exploitation of the earth’s resources in the likes of coal and petroleum. Fossil fuels were continually burned and used with little or no mind for sustainability and consequential impacts on the future. Estimates reveal that, at this level of exploitation, petroleum may not last another half century. The unfortunate reality however, remains that our planet is now edged with catastrophic events like global warming, ozone layer depletion and acid rain due to mans’ reckless exploitation of nature. The increased level of greenhouse gases (GHGs) in the atmosphere is mostly anthropogenic, born from the combustion of fossil fuels. Acts of man have not only endangered humans and our habitats but also fostered multitude of environmental impacts causing global climate changes. Energy is one of the most significant resource for any country, and the search for fuels and renewable energy the world over is inevitable. The exploration of forms of renewable energy in present day is often directed towards biomass resources. These energy forms are called ‘renewable’ because they are constantly replenished and inexhaustible. Renewable energy technologies utilize these sources and convert them into usable forms of energy like electricity, heat, or mechanical power. These technologies are often described as ‘clean’ or ‘green’ because they produce little or no pollutants. This paper therefore, sheds light on bioenergy as an area commanding global attention as a source for cleaner energy options. Among the biomass conversion processes addressed herein, methane production from organic wastes could be most economically feasible in South Africa within the limitations of scale and location.
- Full Text:
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Anthropogenic , Biomass , Global warming
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250343 , uj:26085 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Bioenergy; a substitute and cleaner energy option. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The early man used energy in the form of food as power source for himself. Man further used energy from the sun for warmth and drying processes. With the advent of civilization and advancement, even more energy was needed to meet up with everyday industrialization demands. This led to a persistent pursuit and exploitation of the earth’s resources in the likes of coal and petroleum. Fossil fuels were continually burned and used with little or no mind for sustainability and consequential impacts on the future. Estimates reveal that, at this level of exploitation, petroleum may not last another half century. The unfortunate reality however, remains that our planet is now edged with catastrophic events like global warming, ozone layer depletion and acid rain due to mans’ reckless exploitation of nature. The increased level of greenhouse gases (GHGs) in the atmosphere is mostly anthropogenic, born from the combustion of fossil fuels. Acts of man have not only endangered humans and our habitats but also fostered multitude of environmental impacts causing global climate changes. Energy is one of the most significant resource for any country, and the search for fuels and renewable energy the world over is inevitable. The exploration of forms of renewable energy in present day is often directed towards biomass resources. These energy forms are called ‘renewable’ because they are constantly replenished and inexhaustible. Renewable energy technologies utilize these sources and convert them into usable forms of energy like electricity, heat, or mechanical power. These technologies are often described as ‘clean’ or ‘green’ because they produce little or no pollutants. This paper therefore, sheds light on bioenergy as an area commanding global attention as a source for cleaner energy options. Among the biomass conversion processes addressed herein, methane production from organic wastes could be most economically feasible in South Africa within the limitations of scale and location.
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Buffering efficacy and interaction of minerals in clayey soil with contaminants from landfilling and mining activities: a bird-eye view
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Mines and mineral resources - Environmental aspects , Clay soils , Fills (Earthwork) , Acid mine drainage - Environmental aspects
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/188255 , uj:20992 , Citation: Agbenyeku, E., Muzenda, E. & Msibi, M. 2016. Buffering efficacy and interaction of minerals in clayey soil with contaminants from landfilling and mining activities : a bird-eye view.
- Description: Abstract: The drastic growth in global population, energy resource use, industrial and infrastructure development have led to enormous problems in global conditions and contending environmental challenges. In recent years, South Africa has intensified research on industrialisation and associated environmental problems regarding waste generation, ecosystem matters, human and environmental health risk assessment, and waste management systems. The study has made it clear that geo-environments in and around landfills, and mines are severely contaminated by toxic substances not limited to heavy metals and organic compounds. The allencompassing introductory presentation in this paper based on a bird-eye view- review approach, pinpoints the present state from site reconnaissance, and impact of landfilling and mining operations in areas with such activities. This study however, has paved way for subsequent technically intense investigations on assessing the buffering efficacy of natural soils from affected sites. This include examining the interaction of pollutants with the soil minerals in succeeding papers towards curtailing soil, surface, subsurface and ground water contamination which invariably affect human and environmental health.
- Full Text:
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Mines and mineral resources - Environmental aspects , Clay soils , Fills (Earthwork) , Acid mine drainage - Environmental aspects
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/188255 , uj:20992 , Citation: Agbenyeku, E., Muzenda, E. & Msibi, M. 2016. Buffering efficacy and interaction of minerals in clayey soil with contaminants from landfilling and mining activities : a bird-eye view.
- Description: Abstract: The drastic growth in global population, energy resource use, industrial and infrastructure development have led to enormous problems in global conditions and contending environmental challenges. In recent years, South Africa has intensified research on industrialisation and associated environmental problems regarding waste generation, ecosystem matters, human and environmental health risk assessment, and waste management systems. The study has made it clear that geo-environments in and around landfills, and mines are severely contaminated by toxic substances not limited to heavy metals and organic compounds. The allencompassing introductory presentation in this paper based on a bird-eye view- review approach, pinpoints the present state from site reconnaissance, and impact of landfilling and mining operations in areas with such activities. This study however, has paved way for subsequent technically intense investigations on assessing the buffering efficacy of natural soils from affected sites. This include examining the interaction of pollutants with the soil minerals in succeeding papers towards curtailing soil, surface, subsurface and ground water contamination which invariably affect human and environmental health.
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Chemical alterations in three clayey soils from percolation and interaction with acid mine drainage (AMD)
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Acid mine drainage , Subtropical clayey soils , Contaminant migration
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/212627 , uj:21000 , Citation: Agbenyeku, E., Muzenda, E & Msibi, M. 2016. Chemical alterations in three clayey soils from percolation and interaction with acid mine drainage (AMD).
- Description: Abstract: The issues of acid mine drainage (AMD) from mining activities is not a new phenomenon to the present day developing South Africa as well as in most developed countries around the globe. However, the persistent rise in environmental contamination in South Africa is drastically attracting massive concerns. Vital concerns of AMD in South Africa still remain the threat to soil, surface, subsurface and ground water reserves among others, which consequentially impact human and environmental health. This insistent challenge has given rise to the need for investigating the buffering efficacy of clayey mineral soils for use as natural contaminant barriers to contaminant species from AMD. Therefore, the study presented herein, was channeled towards assessing the chemical alterations in three clayey soils from permeation and interaction with AMD via successive protracted percolation up to 18-25 pore volume passage of AMD through the respective soil medium. The final hydraulic conductivity measured, ranged between 1.3 × 10-11 m/s and 1.5 × 10-11 m/s. The obtained pH, electrical conductivity and solute breakthrough curves indicated the soils had low acid-buffering efficacies. Chemical species such as Na, Co and SO42- were highly dissolved due to attack on the soil grains by AMD. Chemical species were also released from the soils including the dissolution of metals and desorption of chemical species from AMD attack. As such, the study revealed that the buffering efficacies of the respective tested clayey soils to AMD chemical contaminants were generally ineffective.
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- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Acid mine drainage , Subtropical clayey soils , Contaminant migration
- Language: English
- Type: Article
- Identifier: http://hdl.handle.net/10210/212627 , uj:21000 , Citation: Agbenyeku, E., Muzenda, E & Msibi, M. 2016. Chemical alterations in three clayey soils from percolation and interaction with acid mine drainage (AMD).
- Description: Abstract: The issues of acid mine drainage (AMD) from mining activities is not a new phenomenon to the present day developing South Africa as well as in most developed countries around the globe. However, the persistent rise in environmental contamination in South Africa is drastically attracting massive concerns. Vital concerns of AMD in South Africa still remain the threat to soil, surface, subsurface and ground water reserves among others, which consequentially impact human and environmental health. This insistent challenge has given rise to the need for investigating the buffering efficacy of clayey mineral soils for use as natural contaminant barriers to contaminant species from AMD. Therefore, the study presented herein, was channeled towards assessing the chemical alterations in three clayey soils from permeation and interaction with AMD via successive protracted percolation up to 18-25 pore volume passage of AMD through the respective soil medium. The final hydraulic conductivity measured, ranged between 1.3 × 10-11 m/s and 1.5 × 10-11 m/s. The obtained pH, electrical conductivity and solute breakthrough curves indicated the soils had low acid-buffering efficacies. Chemical species such as Na, Co and SO42- were highly dissolved due to attack on the soil grains by AMD. Chemical species were also released from the soils including the dissolution of metals and desorption of chemical species from AMD attack. As such, the study revealed that the buffering efficacies of the respective tested clayey soils to AMD chemical contaminants were generally ineffective.
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Circular defect as potential pathway in polyethylene forming part of a geo-composite lining system
- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Leachate , Geo-composite liners , Buffer , Geomembranes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217523 , uj:21650 , Citation: Agbenyeku, E.E.O., Muzenda, E. & Msibi, M.I. 2016. Circular defect as potential pathway in polyethylene forming part of a geo-composite lining system.
- Description: Abstract: Geo-composite barriers under leachate leakage through circular defects in a geomembrane were tested in a small-scale laboratory model. A soil barrier-24 mm thick, polyethylene plastic-2mm thick with centered 5 mm hole simulated the circular defected geomembrane and a 225 mm thick buffering profile (BP) completed the experimental setup. A Modular Consolidometer-Percolation Column Hybrid model of 160 mm diameter is coupled to a hydraulic pressure frame capable of applying up to 1000 kPa pressure to the liner. Leakages through barrier-BP system were evaluated for tests under pressure of up to 150 kPa. Measured leakage rates for good geomembrane/soil interface contact conditions were found to be valid whereas that of a perfect contact condition was unachievable in this study. However, outcomes show notable reduction in leakage rates with increased pressure, p, on the geomembrane. This is plausibly due to reduced barrier system transmissivity, θ, and densification of the barrier. Concentrations of dreaded Organic matter in the BP after percolation tests confirmed leakage through the defected polyethylene-soil liner and showed poor buffering abilities of three natural soils investigated in this study to migrating organics.
- Full Text:
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Leachate , Geo-composite liners , Buffer , Geomembranes
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217523 , uj:21650 , Citation: Agbenyeku, E.E.O., Muzenda, E. & Msibi, M.I. 2016. Circular defect as potential pathway in polyethylene forming part of a geo-composite lining system.
- Description: Abstract: Geo-composite barriers under leachate leakage through circular defects in a geomembrane were tested in a small-scale laboratory model. A soil barrier-24 mm thick, polyethylene plastic-2mm thick with centered 5 mm hole simulated the circular defected geomembrane and a 225 mm thick buffering profile (BP) completed the experimental setup. A Modular Consolidometer-Percolation Column Hybrid model of 160 mm diameter is coupled to a hydraulic pressure frame capable of applying up to 1000 kPa pressure to the liner. Leakages through barrier-BP system were evaluated for tests under pressure of up to 150 kPa. Measured leakage rates for good geomembrane/soil interface contact conditions were found to be valid whereas that of a perfect contact condition was unachievable in this study. However, outcomes show notable reduction in leakage rates with increased pressure, p, on the geomembrane. This is plausibly due to reduced barrier system transmissivity, θ, and densification of the barrier. Concentrations of dreaded Organic matter in the BP after percolation tests confirmed leakage through the defected polyethylene-soil liner and showed poor buffering abilities of three natural soils investigated in this study to migrating organics.
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Energy Efficiency as a drive towards sustainable development
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Efficiency , Energy , Energy conservation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250332 , uj:26083 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Energy Efficiency as a drive towards sustainable development. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: It has long been established that the economic development of any nation is deeply associated to its energy consumption levels. Over the years however, the insistent increase in the demand for energy triggered a significant utilization of fossil fuels which adversely impacted the environment. This paper therefore, in line with the numerous efforts made around the world, including in South Africa, offers further insight to the significance of the efficient use of energy and its conservation. Hence, it is pertinent to note that one unit of energy saved at the consumer end evades 2.5-3 times fresh capacity addition. Moreover, such savings via the efficient use of energy can be achieved at less than one-fifth of the cost of new capacity generation. Considering that the per capita consumption in South Africa is likely to grow with growth in economy, thereby increasing the energy demand, the efficient use and conservation of energy has become even more crucial. In simple terms, per capita energy consumption is greatly indicative of the wellbeing of human life. The dismal levels of energy inefficiency the world over, has impacted the atmosphere and caused climate changes. The resultant rise in global temperature affects the complex web of systems that permit life to flourish on earth such as rainfall, wind patterns, ocean currents and distribution of plant and animal species. For these reasons, energy conservation programmes get carbon credit from the United Nations Framework Convention on Climate Change (UNFCCC) which emphasizes how energy efficiency is key to all enterprises, especially for energy intensive industries. As such, any successful energy conservation programme needs the commitment of top management in giving equal importance in their corporate objective as manpower, raw material, production and sales. Furthermore, the paper posits that in actualizing the critical energy saving potential envisaged in South Africa, there should be efforts from entrepreneurs, State Agencies and the Government as “energy conservation is always a win-win situation for all stakeholders”.
- Full Text:
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Efficiency , Energy , Energy conservation
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250332 , uj:26083 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Energy Efficiency as a drive towards sustainable development. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: It has long been established that the economic development of any nation is deeply associated to its energy consumption levels. Over the years however, the insistent increase in the demand for energy triggered a significant utilization of fossil fuels which adversely impacted the environment. This paper therefore, in line with the numerous efforts made around the world, including in South Africa, offers further insight to the significance of the efficient use of energy and its conservation. Hence, it is pertinent to note that one unit of energy saved at the consumer end evades 2.5-3 times fresh capacity addition. Moreover, such savings via the efficient use of energy can be achieved at less than one-fifth of the cost of new capacity generation. Considering that the per capita consumption in South Africa is likely to grow with growth in economy, thereby increasing the energy demand, the efficient use and conservation of energy has become even more crucial. In simple terms, per capita energy consumption is greatly indicative of the wellbeing of human life. The dismal levels of energy inefficiency the world over, has impacted the atmosphere and caused climate changes. The resultant rise in global temperature affects the complex web of systems that permit life to flourish on earth such as rainfall, wind patterns, ocean currents and distribution of plant and animal species. For these reasons, energy conservation programmes get carbon credit from the United Nations Framework Convention on Climate Change (UNFCCC) which emphasizes how energy efficiency is key to all enterprises, especially for energy intensive industries. As such, any successful energy conservation programme needs the commitment of top management in giving equal importance in their corporate objective as manpower, raw material, production and sales. Furthermore, the paper posits that in actualizing the critical energy saving potential envisaged in South Africa, there should be efforts from entrepreneurs, State Agencies and the Government as “energy conservation is always a win-win situation for all stakeholders”.
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Engineered geo-composite liner : an empirical look at contaminant travel through a circular punctured defect in a lining system
- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Geo-composite liners , Contaminant transport
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217539 , uj:21652 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2016. Engineered geo-composite liner : an empirical look at contaminant travel through a circular punctured defect in a lining system.
- Description: Abstract: Small-scale laboratory tests on the effect of contaminant travel in geo-composite liners through circular punctured geomembrane were conducted in a modeled device. The influence of pressure on contaminant flow rate, contaminant transport and the buffering ability of natural soil profile were investigated. Flow through the geo-composite liner-buffering profile (BP) system was measured for tests with the punctured geomembrane under loads of up to 150 kPa. Results and analysis showed significant reduction in flow rate with increased pressure on the system. This reduction is attributed to the reduced barrier system transmissivity, θ and soil liner compressibility. The flow rate data for tests with geomembrane in this study were compared with predicted values using equations from Forchheimer (1930) and Giroud et al., (1989). The comparison showed inapplicability to this study and in practice if perfect contact conditions at the geomembrane/soil interface are assumed. However, equations from Giroud (1997) for good contact conditions gave reasonable flow rate predictions through punctured geomembrane of geo-composite liners.
- Full Text:
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Geo-composite liners , Contaminant transport
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217539 , uj:21652 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2016. Engineered geo-composite liner : an empirical look at contaminant travel through a circular punctured defect in a lining system.
- Description: Abstract: Small-scale laboratory tests on the effect of contaminant travel in geo-composite liners through circular punctured geomembrane were conducted in a modeled device. The influence of pressure on contaminant flow rate, contaminant transport and the buffering ability of natural soil profile were investigated. Flow through the geo-composite liner-buffering profile (BP) system was measured for tests with the punctured geomembrane under loads of up to 150 kPa. Results and analysis showed significant reduction in flow rate with increased pressure on the system. This reduction is attributed to the reduced barrier system transmissivity, θ and soil liner compressibility. The flow rate data for tests with geomembrane in this study were compared with predicted values using equations from Forchheimer (1930) and Giroud et al., (1989). The comparison showed inapplicability to this study and in practice if perfect contact conditions at the geomembrane/soil interface are assumed. However, equations from Giroud (1997) for good contact conditions gave reasonable flow rate predictions through punctured geomembrane of geo-composite liners.
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Liner-leachate interaction curve models for clayey soils from landfills around the City of Johannesburg
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Atterberg Limits , Clayey Soils , Landfill
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250694 , uj:26130 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Liner-leachate interaction curve models for clayey soils from landfills around the City of Johannesburg. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The study presented herein links to a regression analysis that ties into three mathematical models from the Brutsaert, Mualem and Burdine equations respectively. The paper describes a series of experimental investigations on the characteristic permeation and interaction of three clayey soil types as barrier liners with landfill leachate from around the City of Johannesburg (CoJ), South Africa. From the outcomes therefrom, sequence of logarithmic relationships were projected towards proposing rational approximations of the best curve-fitting bounds using the Grain Size Distribution (GSD) and Atterberg Limits (AL) of the respective soils as selected classification properties. The outcomes which generally revealed reasonable indicative values were expressed using the weighted Plasticity Indices (PI) of the respective soils in conformance to Sitarenios et al. The two curve-fitting parameters x and z incorporated to simulate the Liner-Leachate Interaction Curve (LLIC) of the three clayey soils sampled from respective landfills around the CoJ, South Africa yielded 118, 0.6; 1211, 0.6; 1058, 0.6 in the Brutsaert model, 0.1, 1.2; 0.0, 1.5; 0.0, 1.5 in the Mualem model and 0.1, 2.4; 0.0, 2.6; 0.0, 2.7 in the Burdine model for samples A, B and C respectively, with a general R2 value of 0.904.
- Full Text:
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Atterberg Limits , Clayey Soils , Landfill
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250694 , uj:26130 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Liner-leachate interaction curve models for clayey soils from landfills around the City of Johannesburg. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The study presented herein links to a regression analysis that ties into three mathematical models from the Brutsaert, Mualem and Burdine equations respectively. The paper describes a series of experimental investigations on the characteristic permeation and interaction of three clayey soil types as barrier liners with landfill leachate from around the City of Johannesburg (CoJ), South Africa. From the outcomes therefrom, sequence of logarithmic relationships were projected towards proposing rational approximations of the best curve-fitting bounds using the Grain Size Distribution (GSD) and Atterberg Limits (AL) of the respective soils as selected classification properties. The outcomes which generally revealed reasonable indicative values were expressed using the weighted Plasticity Indices (PI) of the respective soils in conformance to Sitarenios et al. The two curve-fitting parameters x and z incorporated to simulate the Liner-Leachate Interaction Curve (LLIC) of the three clayey soils sampled from respective landfills around the CoJ, South Africa yielded 118, 0.6; 1211, 0.6; 1058, 0.6 in the Brutsaert model, 0.1, 1.2; 0.0, 1.5; 0.0, 1.5 in the Mualem model and 0.1, 2.4; 0.0, 2.6; 0.0, 2.7 in the Burdine model for samples A, B and C respectively, with a general R2 value of 0.904.
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Susceptibility and defects from the active life of landfill geomembrane liners
- Agbenyeku, Emem-Obong Emmanuel, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Active life , Degradation , Defects
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250653 , uj:26125 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Susceptibility and defects from the active life of landfill geomembrane liners. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The useful/active life of geomembrane (GM) liners are largely reliant on their degradation rate viz-a-viz; the generation of wrinkles, cracks and holes in the liner. This is mostly due to exposure to the elements or by virtue of age as well as the level of leachate or gas leakage specific to a site. The active life of a GM liner in a landfill requires in-depth review of material degradation processes, physical damage and the development of holes by stress cracking. This study highlights the outcomes of a short-term laboratory investigation offering grounds on which projections on medium to long-term landfill liner behaviours can be monitored particularly in Johannesburg, South Africa. Laboratory model of a hole creation born from the active life of a GM liner is pinpointed. It is well known how electrical leak pointer surveys are effective ways of identifying holes caused by physical damage during liner installation and waste disposal, leading to the their repairs. So also is the degradation of the GM liner known as being dependent on the activation energy of the antioxidant depletion process and the oxidative resistance of the material including exposure conditions and limits. In cases where liners are exposed to long-term stresses, stress cracking triggers hole generation. Moreover, the rate of cracking increases once oxidation of the liner begins. As such, approaches to curb the creation of defects are addressed herein.
- Full Text:
- Authors: Agbenyeku, Emem-Obong Emmanuel , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2017
- Subjects: Active life , Degradation , Defects
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/250653 , uj:26125 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2017. Susceptibility and defects from the active life of landfill geomembrane liners. 2nd International Engineering Conference (IEC 2017) Federal University of Technology, Minna, Nigeria.
- Description: Abstract: The useful/active life of geomembrane (GM) liners are largely reliant on their degradation rate viz-a-viz; the generation of wrinkles, cracks and holes in the liner. This is mostly due to exposure to the elements or by virtue of age as well as the level of leachate or gas leakage specific to a site. The active life of a GM liner in a landfill requires in-depth review of material degradation processes, physical damage and the development of holes by stress cracking. This study highlights the outcomes of a short-term laboratory investigation offering grounds on which projections on medium to long-term landfill liner behaviours can be monitored particularly in Johannesburg, South Africa. Laboratory model of a hole creation born from the active life of a GM liner is pinpointed. It is well known how electrical leak pointer surveys are effective ways of identifying holes caused by physical damage during liner installation and waste disposal, leading to the their repairs. So also is the degradation of the GM liner known as being dependent on the activation energy of the antioxidant depletion process and the oxidative resistance of the material including exposure conditions and limits. In cases where liners are exposed to long-term stresses, stress cracking triggers hole generation. Moreover, the rate of cracking increases once oxidation of the liner begins. As such, approaches to curb the creation of defects are addressed herein.
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Transformation and utilization of agricultural waste as component of green concrete for rural housing and development schemes
- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Mandla Innocent
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Rice husk ash , Pozzolana , Strength of materials , Agricultural wastes - Recycling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217530 , uj:21651 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2016. Transformation and utilization of agricultural waste as component of green concrete for rural housing and development schemes.
- Description: Abstract: Several researchers have outlined cost saving and cement blending merits without compromising standards. As such, utilizing artificial pozzolana as supplementary cementitious materials (SCMs) in concrete engineering is well known. However, there is continual search for substitute materials. The use of Rice Husk Ash (RHA) as cementitious constituent in green concrete was studied. Its abundance paved way for the study to look into the compressive strength of the concrete type formed by partly substituting Ordinary Portland Cement (OPC) with RHA under short curing series. Analysis on RHA revealed significant properties of pozzolanic hardening. 60 cubes of 100 mm dimensions were cast with cement replacement by RHA ranging from 0-40% while adopting a 28 day targeted strength of 25 MPa as control. The cubes were cured at relative humidity (RH) of 95-100% and temperature (T) of 22-250C in a chamber for periods of 7, 14, 21 and 28 days. The outcomes displayed trends of strength gain, reduced density and compressive strength with increase in RHA. The 28 days density and strength of the normal concrete was 2465 kg/m3 and 28.57 MPa while the 10% RHA sample (i.e. best substitute matrix) had 2398 kg/m3 and 25.97 MPa respectively. The strength of 10% RHA/OPC concrete (25.97 MPa) was slightly higher than the adopted strength (25 MPa) at 28 days. This signifies its suitability as concrete constituents and can be a major cost reduction factor in rural shelter projects where less structural complexities are required. Hence, it can be employed in the construction of simple foundations and concrete composites.
- Full Text:
- Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Mandla Innocent
- Date: 2016
- Subjects: Rice husk ash , Pozzolana , Strength of materials , Agricultural wastes - Recycling
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/217530 , uj:21651 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, M.I. 2016. Transformation and utilization of agricultural waste as component of green concrete for rural housing and development schemes.
- Description: Abstract: Several researchers have outlined cost saving and cement blending merits without compromising standards. As such, utilizing artificial pozzolana as supplementary cementitious materials (SCMs) in concrete engineering is well known. However, there is continual search for substitute materials. The use of Rice Husk Ash (RHA) as cementitious constituent in green concrete was studied. Its abundance paved way for the study to look into the compressive strength of the concrete type formed by partly substituting Ordinary Portland Cement (OPC) with RHA under short curing series. Analysis on RHA revealed significant properties of pozzolanic hardening. 60 cubes of 100 mm dimensions were cast with cement replacement by RHA ranging from 0-40% while adopting a 28 day targeted strength of 25 MPa as control. The cubes were cured at relative humidity (RH) of 95-100% and temperature (T) of 22-250C in a chamber for periods of 7, 14, 21 and 28 days. The outcomes displayed trends of strength gain, reduced density and compressive strength with increase in RHA. The 28 days density and strength of the normal concrete was 2465 kg/m3 and 28.57 MPa while the 10% RHA sample (i.e. best substitute matrix) had 2398 kg/m3 and 25.97 MPa respectively. The strength of 10% RHA/OPC concrete (25.97 MPa) was slightly higher than the adopted strength (25 MPa) at 28 days. This signifies its suitability as concrete constituents and can be a major cost reduction factor in rural shelter projects where less structural complexities are required. Hence, it can be employed in the construction of simple foundations and concrete composites.
- Full Text:
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