Browsing by Author "Miria Frances Agunyo"

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    Assessing the economic feasibility of integrated waste to use systems for Uganda
    (Avanti Publishers, 2021-09-08) Miria Frances Agunyo; Sarah Kizza-Nkambwe; Kukunda Elizabeth Bacwayo
    Waste and sanitation Management is a major challenge in urban areas in Uganda where waste is composed of at least 70% organic content and is basically collected and disposed of in landfills. While 90% of the sanitation facilities used are onsite systems often requiring additional treatment of sewage and faecal matter sewage, yet faecal and sewage sludge treatment plants are few. The projected population increase is expected to further influence urbanization, increasing the need for basic waste and sanitation services. Integrated Waste to Use systems that consider combined management of organic waste streams i.e. biowaste, animal waste, sewage and faecal sludge, could be a viable solution for the urban areas. The systems which consist of a combination of anaerobic digestion, composting, incineration and solar drying technologies promote resource recovery in the form of biogas, briquettes and organic fertilizer. The economic feasibility of the Waste to Use systems was carried out and the results indicated that the feasibility of the systems was positively influenced by the inclusion of the anaerobic digestion process, which allowed for recovery of biogas and digestate as organic fertilizer. Furthermore, a combination of low system investment costs, increased revenues from resource recovery, consideration of equity capital of at least 30%, interest rate of at most 10% and fugitive emissions less than 7 % would positively influence the economic feasibility of the system alternatives.
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    Evaluation of Agricultural Waste-Based Briquettes as an Alternative Biomass Fuel for Cooking in Uganda
    (East African Nature & Science Organisation, 2024-02-27) Sarah Kizza-Nkambwe; Junior Senyonga Kasima; Maxmillan Mpewo; Miria Frances Agunyo
    Wood fuel has been adopted as a feasible alternative to cooking energy sources in efforts to replace fossil fuels. However, the exorbitant use of wood fuel has raised concern as it is the major cause of forest cover loss in Uganda. Briquettes have been recommended as sources of cooking energy with potential to substitute wood fuel. Unfortunately, sawdust, a product of deforestation, is the primary material used in making briquettes in Uganda. This instead augments the problem of fuel-induced deforestation. Agricultural wastes could potentially be converted into briquetting materials for generation of cooking energy, although these are less studied in Uganda. Thus, this study established the potential of agricultural wastes as alternative briquetting materials for use in cooking. Four fuel types: charcoal from Mangifera indica, firewood of Eucalyptus grandis, carbonized and non-carbonized briquettes from agricultural wastes, all from within Mukono District were used for the study. Laboratory based experiments were used to determine the physico-chemical characteristics of the fuels. Data were analysed using R software, Ver. 4.2.3. Carbonised briquettes’ mean performance measures were higher than conventional fuels (p≤0.05) and non-carbonised briquettes. The amount of energy required to attain experimental boiling point of water was higher (p≤0.05) in conventional fuels and non-carbonised briquettes than in carbonised briquettes. Duration to boil 5 litres of water was least with the conventional fuel sources. All the fuel sources’ emissions exceeded the maximum range recommended for indoor carbon monoxide levels. However, the particulate matter emission was lower in carbonised briquettes and charcoal than the other fuel sources. Agricultural waste-based carbonised briquettes could effectively be used as an alternative cooking energy source in Uganda. The study recommends conducting cost benefit analyses on the use of agricultural waste-based briquettes as cooking energy sources.
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    Sustainability Assessment of Integrated Waste-to-Use Systems: A Case of Uganda
    (2022-12-31) Miria Frances Agunyo
    For countries like Uganda where organic waste composition accounts for at least 70% of the solid waste generated, collected, and disposed of at landfills and dumpsites, recovery of resources from the waste stream is crucial. This is because disposal of thewaste in the landfills/dump sites exerts more pressure on land as a resource in addition to the environmental negative impacts associated with the degradation of the waste in the landfills, pollution of groundwater from leachate, generation of greenhouses gases, bad odor, and poor aesthetics. Moreover, given that the country also grapples with sewage and faecal sludge treatment and management due to the limited plants in place, alternative Waste-to-Use systems that promote resource recovery and management of various organic waste streams such as biowaste, animal manure, sewage/faecal sludge and wastewater could be a viable solution. The systems which consist of a combination of various technologies such as anaerobic digestion, incineration, landfilling, composting, and pyrolysis to produce briquettes boast of managing various organic waste streams and potential for application in various entities such as housing estates, towns/cities, at institutions. To assess the sustainability of such systems, multicriteria decision analysis was used. The results indicated that if trade-off of any aspect was considered i.e., technical, environmental, social, and financial, the Waste-to-Use systems. were preferred i.e., a system consisting of composting and anaerobic digestion technologies. Also, a sustainability framework for the assessment of similar systems was proposed and it highlights the importance of involving stakeholders through the various stages such as, situation analysis, problem identification and definition, criteria and indictor selection, elicitation of scores and weight so that transparency in decision making can be boosted.