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Geoenvironmental study of hydraulic and mechanical properties of waste containment base barriers

- Agbenyeku, Emmanuel Emem-Obong

  • Authors: Agbenyeku, Emmanuel Emem-Obong
  • Date: 2015-10-01
  • Type: Thesis
  • Identifier: uj:14220 , http://hdl.handle.net/10210/14672
  • Description: M.Phil. (Civil Engineering) , The challenge of buried domestic solid wastes in landfill sites is viewed from the perspective of leachate migration and contamination in the substrate. Generally, this happens through the passage of the contaminant into the barrier lining material. The use of mineral liners as useful economic containment component has resulted in the assessment of their efficiency as barrier materials and in the attenuation of migrating contaminant species. To evaluate the potential use of mineral liners as containment base barriers to domestic waste, natural occurring soil samples from three different waste disposal sites in City of Johannesburg, South Africa were collected and studied. Bentonite-GCL was tested to serve as a bench mark for the three different tested soil samples. The various chemical constituents of the landfill leachate were determined from samples taken from the basins designed to collect the leachate from the respective landfill sites. In this study, series of tests on geocomposite liners under the effect of leachate flow through circular geomembrane defects and tests without geomembranes were conducted in a small-scale model device. A 24mm thick soil barrier layer underlain a 2mm thick polyethylene plastic with centred 5mm hole to simulate defected geomembrane and a 225mm thick attenuation layer (AL) in line with the American Society for Testing and Materials (ASTM) D-3776 and D-5084 constituted the model setup. The model device, a Modular Consolidometer-Percolation Column Hybrid with 160mm diameter was placed on a loading frame capable of applying over 500kPa pressure to the composite barrier...
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Interpretation of breakthrough curves and percolation factors from sub-tropical smectite, fe-chlorite and kaolinite clayey soil-AMD interactions

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

Industrial waste modified 1-dimensional compressibility of kaolinitic clay

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2014
  • Subjects: Fly ash , Kaolinitic clay , Soil modification , Soil compressibility , Industrial wastes , Landfills , Fills (Earthwork)
  • Type: Article
  • Identifier: http://ujcontent.uj.ac.za8080/10210/365833 , uj:5053 , http://hdl.handle.net/10210/13592
  • Description: The modification of soil has become a major drive in construction and geoenvironmental engineering in recent years. Researches towards the effective incorporation of wastes as cement blenders and enhancers with environmental friendly impacts are increasing. This paper channeled the utilization of commercially available industrial waste- Fly ash (FA) in South Africa towards the modification and improvement of kaolinitic clay sampled from a disposal site. One-dimensional consolidation tests were conducted to investigate the effect of integrating varied proportions of FA on the compressibility behavioral patterns of a parent compressible landfill material. Compacted specimens were modified at optimum water content (OWC) and maximum dry unit weight (MDUW) by the incorporation of an industrial waste material to the parent soil. The generated specimens were subjected to incremental vertical loadings/pressures in a fixed ring odometer. This was done to simulate the impact of waste loads from a typical landfill on the consolidation characteristics of the modified specimens in a view for use as bottom liners in domestic waste containment facilities. The addition of different proportions of FA waste to the kaolinitic parent clay resulted in considerable improvements in compaction characteristics. Thus, the results of this study revealed that the incorporated industrial waste effectively increased one-dimensional stiffness and as such, successfully decreased settlement. Under adequate strength and operative conditions, the modified kaolinitic clay soil can withstand loadings from waste heaps and after recommended scrutiny by experts, may be initiated into landfill designs as an eco-friendly cost reducing agent.
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Prospective inclination of research and engineering education

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Sustainability , Engineering education , Sociotechnical systems
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/123934 , uj:20853 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. Prospective inclination of research and engineering education.
  • Description: Abstract: The roles of Engineers are generally vital as their knowledge and expertise play a pivotal part in societal improvement, offer empowering ideas, innovations and initiatives that motivate financial and economic progress, enrich social and physical infrastructures, and also stimulate transformations that advance quality and standard of living. Concurrently, there are enormous challenges weighing on all facets of research and development (R&D), industry and manufacturing owing to globalization and circulated manufacturing. On this note, the corporate and commercial setting of manufacturing enterprises are categorized by incessant modification and growing intricacies. Most companies are in dire need of dynamic technical solutions as well as handling composite socio-technical systems geared towards substantially contributing to the sustainable growth and development of manufacturing and the environment. For this reason, in the ever changing industrial and business world of Engineering, Health delivery, Environment, Transportation, Logistics and Supply chain amongst others, researchers and graduates are profusely required once they display the ability to comprehend both composite technological processes and the resourceful arts and social skills. Thus, through the proficient technical and communication skills of engineering managers, various team-based activities are successfully supervised and executed. As such, aiming at the crucial role of engineering in solving simple to compound global problems make the career attractive to all gender of students.
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Caco3 precipitation in selected bacteria mixture by activated microbial induction

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Natural soils , Bacillus subtilis , Sporosarcina pasteurii , Bacteria , Microbial attack
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93685 , uj:20379 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, I.M. 2016. Caco3 precipitation in selected bacteria mixture by activated microbial induction.
  • Description: Abstract: Activated microbial induction of CaCO3 precipitation (AMICP) is a niche with innovative approaches that involves the exploration of bacterial attacks towards the alteration/transformation of the physical properties of soils. A handful have been documented on this technology in developed countries however, much is yet to be understood in developing African countries like South Africa, just as vermicomposting and waste water treatment technologies are gaining grounds. It is widely known that AMICP by urea hydrolysis in natural soils is possibly affected by contacts between ureolytic and non-ureolytic bacteria, the study explored a designed and experimental assessment of the relations between ureolytic and nonureolytic bacteria and their interactive effects on AMICP. Through existing studies an artificial leveled groundwater medium was injected with model species of bacteria i.e., ureolytic species Sporosarcina pasteurii and the non-ureolytic species Bacillus subtilis. The control treatment was inoculated with a pure culture of S. pasteurii under measurements of pH, optical density (OD), development of NH4-N, dissolved calcium (DC) and dissolved inorganic carbon (DIC). Outcomes revealed DC precipitated as CaCO3 slower in the control mixture than in the mixed culture irrespective of unfavorable conditions in the mixed culture, i.e., lower concentrations of pH and CO32−. Higher density of bacterial cells in the mixed culture resulted from B. subtilis showing significant higher growth rate than S. pasteurii. Previous authors indicate that the presence of the non-ureolytic bacterial species, B. subtilis, stimulate AMICP process through supply of nucleation sites in the form of non-ureolytic bacterial cells.
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Technology in Africa for sustainable alternative energy growth : an innovative bird eye view

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2015
  • Subjects: Renewable energy , Electricity , Innovative learning
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/73433 , uj:18410 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, I.M. 2015. Technology in Africa for sustainable alternative energy growth : an innovative bird eye view.
  • Description: Abstract: Over the last decade, numerous ideas have insistently emerged and triggered several social, economic and environmental discuss emanating from energy insufficiencies in Africa. A lot around energy poverty are currently argued particularly, on how chiefly Africa’s industrialization is prime to its potential sustainability across all facets of growth and development. Sadly, only few member countries since post-colonialism have earnestly attempted innovative approaches towards new alternative energy schemes. Nonetheless, wasteful sums have drowned in projects of less critical nature. For this reason; an innovative bird eye view (IBEV) portrayed how member countries might augment rates of dispensable energy to increase access to electricity. Hence, versatile industrialization via renewable and greener alternative energy sources can be reached. The employed measures herein, extend past industries and research institutes to involve cultural, institutional, economic and political players of key positions in innovative process. Firstly, a conceptual idea of “learning” was conveyed as vital to IBEV, seeing innovation and production as pertinent and dynamic. On a second note, the work featured instances of trials to create renewable energy industries around the continent. Lastly, the possible transformation of research outlets such as the African Network for Solar Energy (ANSOLE) into inventions was highlighted, emphasizing how innovations might be born from inventions. A vital policy suggestion was that divisions of African “innovative force” such as a technological head like South Africa can for example; engage more with member countries involved in production or assembly while creating beneficial agreements with them. Thus, with mixed innovation schemes, more effective knowledge transfer can be groomed across the continent.
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Experimental view of the sub-tropical clayey soils-acid mine drainage interactions

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Batch sorption , Contaminants , Acid mine drainage (AMD)
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/214156 , uj:21244 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. Experimental view of the sub-tropical clayey soils-acid mine drainage interactions.
  • Description: Abstract: Issues of acid mine drainage (AMD) from mining activities is a lingering phenomenon to the present day developing South Africa as well as in most developed countries around the globe. However, the insistent 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 are known to consequentially affect human and environmental health. This persistent challenge has given rise to the need for investigating the buffering efficacy of clayey mineral soils for use as natural contaminant barriers to pollutant species from AMD. Also, increasing climatic changes, growing population and depletion of natural resources from mining and related operations have further increased these environmental challenges. However, the constantly growing challenges gave bearing for this study to experimentally outline series of vital tests on three subtropical clayey soils infused with AMD for the determination of their mineral buffering efficacy towards potential use as natural containment liners in areas affected by AMD. Series of dissolution, diffusion and water sampling analysis were initiated herein on the respective soil systems leading to progressive investigations and analysis for decisive interpretations in subsequent studies. In summary, the general outcome was below the accepted criterion specified for clay liner construction in South Africa. However, the tested samples can be incorporated into the design and construction of composite barriers for acid-generating wastes.
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Interpretation of breakthrough curves and seepage bounds from kaolinite, halloysite and illite/vermiculite mixed layer sub-tropical clayey soil-AMD interactions

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

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

Environmental contamination threat from the deposition of construction and demolition waste (CDW)

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Construction and demolition waste , Effluent , Landfill
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/215494 , uj:21423 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. Environmental contamination threat from the deposition of construction and demolition waste (CDW).
  • Description: Abstract: Growing population, industrialization and infrastructure development have resulted in enormous waste generation over the past decades. The disposal of vast amounts of waste remains a major challenge. However, in the globalized world recycling has become a main option for managing wastes while in other parts of the globe, landfilling is done due to waste handling difficulties. South Africa is one of many countries where landfilling activities is high, as roughly 75% of daily generated solid waste is disposed in landfills. This includes massive amounts of construction and demolition wastes (CDW) from reconstruction and development activities. South Africa depends on landfilling as a system of waste management which in the foreseeable future would linger till feasible recycling options are initiated. As such, the generation and seepage of leachate into soil, water reserves is probable in such dump sites due to exposure of the waste bodies to rain and run-offs. A bespoke device was used in the study to investigate the impacts of disposing CDW in open dumps paying mind to an unlined site relying on the geology of the area as worst case scenario. To generate leachate, the device was coupled with CDW in a bottom chamber and de-ionized water percolated the system from a reservoir. Arsenic, Copper and Chromium from the generated leachate effluent were analyzed by full spectral method and were compared to the South African standard of drinking water. Targeted ions were found to decrease over the testing period and it was however, clear that improper disposal of CDW could have consequential impacts on human and environmental health.
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Synergizing food-energy-water (FEW) resources for sustainable benefits

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla, Masebinu, Samson Oluwasegun

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla , Masebinu, Samson Oluwasegun
  • Date: 2015
  • Subjects: Synergy , Sustainability , FEW resources
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72767 , uj:18325 , Citation: Agbenyeku, E.E.O. et al. 2015. Synergizing food-energy-water (FEW) resources for sustainable benefits.
  • Description: Abstract: The drastic pursuit of economic, urbanized and globalized growth in recent decades have impacted severely on the natural ecosystem and available resources. The insistent climate change is further sustained by enormous food and energy production wastages. This also accounts for the increased tension on water supply and organic practices as consequences of an upset ecosystem; leading to unstable temperature changes, changes to normal weather patterns, floods and drought, melting glaciers and rising sea heads- all to which potentially affects the sustenance of man and the environment. As such, synergizing the food-energy-water (FEW) scarce resources and understanding their potential interactive merits as against their isolated short lived advantages have become an area of interest in recent years. This has driven the discuss herein towards the sustainable benefits of knotting the FEW scarce resources, as all three elements must be unified for ensured beneficial outcomes. The paper also highlighted the FEW interactive challenges and pathways of resource conservation particularly, in the dire need for food security in present time. The paper therefore holds a general discuss that posits the interactive link between the limited FEW resources as a platform towards sustainable conservative benefits of all three elements to man and the environment.
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An experiential perspective of leachate seepage through defected geomembrane of geo-composite barrier

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Geo-composite , Geomembrane , Ions
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/215487 , uj:21422 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. An experiential perspective of leachate seepage through defected geomembrane of geo-composit.
  • Description: Abstract: Laboratory tests using a small-scale model device were carried out on leachate seepage in geo-composite barriers due to circular geomembrane defects. Various pressures simulating actual landfill waste loads were applied to the barrier systems. Seepage rate, anion migration and the attenuation tendency of a natural mineral layer were investigated. Seepage through the geo-composite barrier-attenuation strata (AS) system was determined under waste loads of up to 150 kPa impacting the defected geomembrane liner. The findings revealed appreciable reduction in seepage rate with increased pressure on the system. The reduction is ascribed to the reduced barrier transmissivity, θ and compressed soil layer. Data for seepage rates were compared with predicted values from Forchheimer’s (1930) and Giroud’s et al (1986) equations. The comparisons displayed inapplicability to this study and to real practice, if conditions of perfect contact at the geomembrane/soil interface are assumed. Nonetheless, Giraud’s (1997) equation for good contact condition gave reasonable prediction of seepage rate through geo-composite liners with defected geomembrane.
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Developing countries and the need for building engineering capacity

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Education , Capacity , Infrastructure
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/123926 , uj:20852 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. Developing countries and the need for building engineering capacity.
  • Description: Abstract: In the global fight for additional world security, stability and sustainability, the need for enhancing human, institutional and infrastructure capacity in developing countries is insistently of dire concern. To enhance the respective capacities, a concrete structure of technologically equipped people to efficiently advance their economies, quality and standard of living are drastically required. Such type of structure will enable the mixture of foreign capital via pulling in transnational corporations and establishments to invest in the developing country, aid in making the most of international aid funds, and offer a basis for business development by indigenous entrepreneurs. For these reasons, the United Nations Educational, Scientific and Cultural Organization (UNESCO) and World Federation of Engineering Organizations (WFEO) are intensifying key efforts in developing countries as a synchronized approach towards technical capacity building. The paper therefore unpacks some basic attempts and outcomes by UNESCO and WFEO in empowering competent engineering and science graduates/ engineers towards building a sustainable circular economy.
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Potential risks of CCA-treated wood destined to landfills

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2015
  • Subjects: Landfills , CCA-treated wood , Percolation
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72876 , uj:18340 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, I.M. 2015. Potential risks of CCA-treated wood destined to landfills.
  • Description: Abstract: In recent years, recycling has become the first best option of dealing with waste before landfilling is considered in cases of handling difficulties. In South Africa however, 41,000 tons of solid waste is destined for landfills daily; which includes huge chunks of waste from construction and demolition activities. The continued reliance of South Africa on the landfilling system could extend a while until economical recycling alternatives are introduced. Leachate generation and percolation is expected in these landfills on account of infiltration of water into the waste body from rain and/or runoffs. Although, it has been documented that arsenic, copper and chromium percolate soil systems, it however noted that occurring physical, chemical and biological activities may influence mobility of metals from generated leachate. This is particularly evident in cases where Chromated Copper Arsenate (CCA)-treated wood are disposed in monofills with consequential impacts on the environment. Laboratory investigation using a bespoke device to explore the environmental risk of depositing CCA-treated wood in monofills and/or open dumps was done; with a view to simulating worst case scenario of an unlined disposal facility that relied on the geology of the site. This scenario best indicates high concentrations and maximum formation of heavy metals. The bespoke device was assembled with chopped untreated wood and CCA-treated wood in a bottom chamber respectively, and de-ionized water was allowed to seep through from a reservoir forming leachate. The targeted chemical ions (arsenic, copper and chromium) from the leachate were analyzed by way of full spectral method on the effluent and were compared to South African standard of drinking water. The study therefore, revealed that CCA-treated wood formed hazardous concentration levels of chromium and arsenic which if not properly contained in real cases, could inflict severe contamination consequential to human and environmental health.
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Zeolitic mineral liner as hydraulic and buffering material

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2014
  • Subjects: Leachate , Zeolites - Linings , Solid waste management , Hydraulics , Zeolites - Analysis
  • Type: Article
  • Identifier: uj:5093 , http://hdl.handle.net/10210/13683
  • Description: Laboratory tests were done using a bespoke device to investigate landfill leachate seepage through a circular failed geocomposite liner. Pressures simulating actual landfill waste loads were applied to the lining system. The buffering capacity of a natural zeolitic mineral layer was investigated by measuring the leachate seepage rate and anionic (Cl and HCO3) contaminant transport through the geo-composite liner-buffering strata (BS). Simulated landfill waste loads from 25-150kPa were introduced to the system at intervals. The findings showed considerable reduction in seepage rate over the increased pressure. The seepage reduction is ascribed to the reduced liner transmissivity, θ and compressed soil layer. The natural zeolitic soil exhibited poor buffering of Cl ions but showed a fair outcome in the case of HCO3 ions. Data for seepage rates were compared with predicted values from existing equations by Forchheimer and Giroud. The comparisons showed inapplicability to this study and to real life scenarios, if conditions of perfect contact at the polyethylene/soil interface were assumed. Nonetheless, Giroud’s equation for good contact condition gave considerable seepage rate prediction through a failed geo-composite liner.
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Potential efficiency and energy usage in a leachate treatment process

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Landfills , Reverse osmosis , Leachate , Waste , Energy
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/93676 , uj:20377 , Citation: Agbenyeku, E.E., Muzenda, E. & Msibi, I.M. 2016. Potential efficiency and energy usage in a leachate treatment process.
  • Description: Abstract: Generated leachate in landfills is often as a result of the infiltration of rain, surface or running water into waste bodies. Numerous studies have revealed the potential impacts of leachate escape from landfill disposal facilities on human and environmental health. Although much is been done in most landfills in South Africa to ensure minimal leachate escape into immediate soil, surface and groundwater reserves, much more is still required. As such, the option of leachate treatment is gradually been explored. The potential efficiency and energy usage of a landfill waste water treatment plant (WWTP) for a simple leachate treatment process is explored. The WWTP process involves the basic treatment of the leachate with subsequent sequencing batch reactors (SBR), reverse osmosis unit (RO) and evaporation for additional concentration of RO yield. The process efficiency is appraised by conductivity, chemical oxygen demand (BOD), biochemical oxygen demand (BOD) and total nitrogen (TN) measurements. Energy usage is estimated by electrical input power, motor efficiency of power-consuming units and functional hours. 2.2% of the of the WWTP total operational real power consumption is gotten for the primary treatment process with 16.7% corresponding SBR operation and 13.2% RO unit. 2 unit evaporators consumes 61.5% and 0.78% for leachate recirculation to landfill from the total energy usage. Therefore, RO is taken as the most efficient leachate treatment process as it can dispense substantial amounts of water from the landfill leachate pond whereas, the evaporators are energy demanding.
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Interpretation of breakthrough curves and permeation parameters from sub-tropical kaolinite clayey soil-AMD interactions

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

Earthworms as engineers of soil and human health

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2015
  • Subjects: Earthworms , Vermicompost , Soil health
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/72775 , uj:18326 , Citation: Agbenyeku, E.E.O., Muzenda, E. & Msibi, I.M. 2015. Earthworms as engineers of soil and human health.
  • Description: Abstract: Fungi are active degrading initiators of organic matter in soils as many substrates are first populated by sugar fungi e.g., Mucorales. Vermicomposting is now well known and is generally a good organic fertilizer majorly populated by bacteria i.e., nitrogen fixers, sulphur bacteria and phosphate solubilizers. The use of vermicompost in introducing these components into the soil leads to improvement of soil health thereby yielding nutritious food which consequently contributes to human health. A number of organic foliar sprays constitute of components similar to plant growth promoter substances. For example, vermiwash is a good liquid fertilizer proven to harbor plant growth promoting substances. Humification may be supported by vermiwash which also, by virtue of its quality may increase microbial actions to produce enzymes and compounds promoting plant growth. The compounds present in vermiwash may not independently foster plant growth but possibly promote plant growth along with beneficial soil microbes. These products are known to improve soil health and in presence of other products i.e., Gunapasela and Panchagavya can offer healthy nutrition from soil to plant. In recent times, insistent use of soil pollutants in forms of chemical fertilizers as against organic practices has negatively impacted surrounding soils, and in extreme cases surface and groundwater reserves. Lately, genetically modified substances (GMS) are used to nurse plants (with consequential impacts on the soil and invariably on human health) in contrast to, organic measures which nurses the soil (improving cluster of biotic elements and nutrients proportionately mixed) for uptake by plants, consequently leading to healthier soils and food produce beneficial for human health. For this reason, the paper highlights the efficacy of earthworms as a sustainable eco-friendly option constructively engineering soil and human health with minimal environmental and ecological impact.
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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.
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Supporting hands of a tutor towards activity-based education

- Agbenyeku, Emmanuel Emem-Obong, Muzenda, Edison, Msibi, Innocent Mandla

  • Authors: Agbenyeku, Emmanuel Emem-Obong , Muzenda, Edison , Msibi, Innocent Mandla
  • Date: 2016
  • Subjects: Tutors , Activity-based interaction , Questionnaire
  • Language: English
  • Type: Conference proceedings
  • Identifier: http://hdl.handle.net/10210/123942 , uj:20854 , Citation: Agbenyeku, E.E., Muzenda, E & Msibi, I.M. 2016. Supporting hands of a tutor towards activity-based education.
  • Description: Abstract: Tutors generally play a vital role towards the academic success of students at the University of Johannesburg (UJ), South Africa, with specificity of this study on engineering students. As such, UJ continually invest in the drive of tutors through the Academic Development Centre (ADC) towards activity-based education of students or interaction (ABE/I) with students. In most cases, the activity-based interaction between tutors and engineering students may differ amongst tutors however, one common element remains the teaming/grouping of students with one or more tutors as head of the team in different subject/module. Nonetheless, it is emphasized that tutors do not act to assume or supposedly function as lecturers to students. Notwithstanding, the exact role of a tutor in activity-based education is somewhat indistinct to both tutors as well as to students. Nevertheless, to streamline and better inform the tutors of their role and performance as well as help them improve, the study opted for open and closed item questionnaire aimed at appraising the supporting hands/performance of individual tutors in one active semester term. Tutors responses to the open item questions informed the study about their strengths and weaknesses. While responses to the closed items provided insight to the supporting hands of a tutor with respect to the functional operation of a team/group, individual learning processes, the progress of the activity/task, the approach of the tutor to activity-based education and the tutor’s role in imbibing in the students development of critical thinking and problem solving skills.
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