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ItemOptimization of coagulant production from Iron oxide waste powder for Phosphorus removal in municipal wastewater treatment(Makerere University, 2026)Iron oxide waste powder (IOWP) from steel industries is a global challenge and the current disposal methods involving stockpiling or landfilling as solid waste pose a threat to the environment and human health due to its acidic nature. IOWP can be applied as advanced oxidative agents for water treatment and as pigments in paints among others. This study involved synthesis of IOWP-based coagulant for total phosphorus (TP) removal in municipal wastewater treatment. IOWP was characterized by XRF, XRD, SEM, FTIR and Sieve Shaker to evaluate its quality as a precursor for synthesizing IOWP-based coagulant. CCD was used with independent variables; acid concentration, leaching time and IOWP to acid ratio and responses such as iron concentration in leachate and leachate volume. This led to synthesis of the IOWP-based coagulant through the acid dissolution process. The efficacy, applicability and cost-effectiveness of synthesized coagulant in removing TP in municipal wastewater treatment was compared with that of commercial Alum using laboratory jar tests. Findings revealed that IOWP exhibited favorable physicochemical properties including suitable particle size distribution with a pronounced peak at 180 µm, spherical surface morphology, phase composition aligning with those of hematite (α-Fe2O3), high iron oxide content of 98.72% and Fe–O, O–H functional groups conducive for coagulant synthesis. Optimal conditions of the FeCl3 coagulant synthesis included HCl 6M, leaching time of 30 minutes, IOWP to acid ratio of 0.26, stirring speed of 500 rpm and temperature of 90 ℃, yielding 166508 mg/L iron concentration in the leachate. The coagulant demonstrated desirable traits like irregular and agglomerated particles, profile of iron oxychloride lattices, broad absorption attributed to O–H stretching vibrations, and positive zeta potential (+13.52 to −11.18 mV), that enhance phosphate adsorption and complexation in wastewater treatment. Evaluation of the efficacy of the two coagulants in removing TP showed that the IOWP-based (FeCl3) coagulant is more superior at a lower dose of 150 mg/L compared to alum of 200 mg/L as it also improves other water quality parameters such as total suspended solids, turbidity, color, and pH without additional chemical requirement for pH correction before environmental discharge compared to alum. This translates into lower operational costs for municipal wastewater treatment when using the IOWP-based coagulant (0.424 USD/m3) relative to alum (0.767 USD/m3). Therefore, the IOWP based coagulant is a suitable replacement for commercial alum in municipal wastewater treatment contributing to circular economy and import substitution. Key words: IOWP-based coagulant, ferric chloride, alum, optimal dosage, municipal wastewater, optimal conditions.
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ItemDevelopment of briquette from banana brew waste as a waste management strategy for rural communities(Makerere University, 2025)In Uganda, many local banana farmers have increasingly focused on cultivating the 'Kayinja' and 'Kisubi' banana varieties, primarily for brewing traditional Waragi through fermentation. This practice generates substantial quantities of banana brew waste, which is often indiscriminately disposed of, posing environmental and public health concerns. Similarly, for every metric ton of dry cassava processed, approximately 0.93 to 1.12 metric tons of wet cassava bagasse and peels are produced, adding to the agro-waste burden. This study aimed to develop and characterize briquettes made from banana brew waste and banana peels using cassava peel waste as a binder, offering a sustainable waste management approach for rural communities. The objectives included characterization of the raw materials, briquette production, and performance evaluation in terms of physical, thermal, and mechanical properties. Physical and calorific properties of both feedstocks and briquettes were assessed using a thermogravimetric analyzer and a bomb calorimeter, respectively. Elemental composition was estimated using Parkish and Shen models. A Box-Behnken design was applied to guide the experimental process and evaluate the impact of variables such as blending ratio, binder content, and water amount on the quality of the briquettes. Combustion performance was evaluated through water boiling tests, ignition time, burning rate, and specific fuel consumption. The calorific value and drop strength of the produced briquettes ranged between 18.073 MJ/kg and 21.985 MJ/kg, and 92% to 99.6%, respectively.
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ItemEvaluating the impact of lightning strikes on medium voltage lines in Uganda.(Makerere University, 2026)Lightning strikes are a major cause of power outages on medium voltage lines in tropical countries like Uganda. Many medium voltage lines are still vulnerable due to the limited protection systems and the absence of detection systems. The main objective of the study was to evaluate the impact of lightning strikes on medium voltage lines in Uganda. Specific objectives included modelling line configurations under direct and indirect strikes, assessing flashover rates, and studying non-structural factors. This study evaluated the impact of lightning strikes on medium voltage lines in Uganda by studying four configurations (horizontal, wishbone-wye, wishbone-delta, and wishbone-vertical), and nine lines selected from West Nile, Eastern Uganda, and Northern Uganda using software tools EMTP for direct strikes, LIOV-EMTP for nearby strikes, and the statistical methods such as the IEEE standard 1410-2010, and the IEEE standard 1243-1997. Additionally, four insulator types (suspension, line-post, porcelain pin, and composite pin) were studied in COMSOL Multiphysics. The results in EMTP reveal that configurations without an overhead ground wire experience higher induced voltages and currents whereas adding an OHGW reduces these values by 82.24% and 49.36% respectively. Further studies in EMTP reveal that widely spaced surge arresters (5 km or more) are less effective for lines without an OHGW. Further analysis in LIOV-EMTP and the three statistical methods reveal that grounding resistances of above 10 Ohms reduce arrester performance and insulators rated 170 kV peak fail to protect medium voltage lines in areas with high soil resistivity values and struggle to safeguard lines in regions with high lightning ground flash densities where flashover rates are high. COMSOL Multiphysics simulations indicate that composite insulators exhibit lower electric field stress while porcelain insulators show sharper peaks increasing their vulnerability. The study concludes that medium voltage lines in high lightning activity regions should be constructed with an OHGW, use the wishbone-vertical configuration, and the line-post insulator for better performance. Furthermore, increasing the insulator lightning impulse voltage rating to 250 kV peak and maintaining a surge arrester spacing of 3 km or less with an arrester grounding resistance of 5 Ohms or lower are essential measures for better protection against lightning strikes.
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ItemBiomethane production from market organic waste components : a multi-criteria selection, co-digestion and techno-economic assessment(Makerere University, 2026)In Kampala, urban markets generate substantial quantities of market organic waste (MOW), whose management imposes significant economic burdens due to high collection, transportation, and disposal costs, while also contributing to greenhouse gas emissions. Anaerobic digestion (AD) offers a sustainable pathway for converting MOW into biomethane (BioCH4), thereby simultaneously addressing waste management challenges and enhancing access to renewable energy. However, existing literature provides limited guidance on how to systematically ascertain the feasibility of BioCH4 production from heterogeneous MOW components. This study therefore developed an integrated framework to evaluate BioCH4 production from MOW, using Kalerwe market as a case study due to its high waste generation and central role in Kampala’s fresh produce supply chain. The framework combined MOW component selection, experimental AD optimization, and techno-economic analysis (TEA). Key MOW components were selected using a multi-criteria decision-making approach that integrated the Analytical Hierarchy Process (AHP), Entropy Weight Method (EWM), and Weighted Linear Combination (WLC) based on waste composition and theoretical methane potential (BMPth). Co-digestion experiments were then conducted using an augmented simplex-centroid design to optimize substrate mixtures and maximize BioCH4 yield. The Scale-up feasibility was then assessed through TEA using SuperPro Designer, evaluating three distinct scenarios (1, 2 and 3) based on the optimal mixture and actual daily waste quantities from the market. Banana waste (BW), yam waste (YW), and jackfruit waste (JFW) were identified as the most promising components. The optimal mixture (3.00% YW, 74.18% BW, 22.82% JFW) achieved a maximum cumulative methane potential (CMP) of 86.23 mLCH4/gVS. However, observed CMP values fell below theoretical estimates, primarily due to volatile fatty acid (VFA) accumulation, pH decline, and consequent inhibition of methanogenic activity with effects particularly pronounced in YW-rich mixtures. TEA results confirmed the viability of all scenarios, with Scenario 2 (BW baseline) exhibiting the highest performance: 44.49% return on investment (ROI), 74.96% gross margin, 2.25-year payback period (PBP), 52.11% internal rate of return (IRR), and $15.296 million net present value (NPV). Overall, the study demonstrates a structured and transferable framework for MOW valorisation that integrates feedstock selection, process optimization, and economic evaluation to support sustainable waste-to-energy systems in urban market settings.
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ItemFeasibility of Burundi's solar PV potential for regional energy supply(Makerere University, 2026)Burundi, like many Sub-Saharan African countries, faces acute energy challenges characterized by limited access to electricity, high dependence on traditional biomass, and an underdeveloped energy infrastructure. Despite its abundant solar resource potential, the country has yet to harness solar energy effectively as a major contributor to its energy mix. This study evaluates the technical, economic, and environmental feasibility of deploying solar photovoltaic (PV) systems across Burundi to promote sustainable development and industrial growth. Using empirical solar data (sunshine duration and temperature variations) over seven years from 14 meteorological stations, alongside average hourly load demand profiles from electrified locations, HOMER Pro software was employed to design and optimize PV-based systems. Results reveal that solar irradiance ranges annually from 4.6 to 5.9 kWh/m2/day in the fourteen locations under study. These findings also show that in regions such as Makamba, Imbo, and Gisozi, the global horizontal irradiance exceeds 5.8 kWh/m²/day, making them prime candidates for PV deployment. In these regions, financial analyses based on the system designed to meet the demand reveal that Net Present Cost (NPC), Internal Rate of Return (IRR), Payback Period (PBP), and Levelized Cost of Energy (LCOE) demonstrate that PV-battery systems are both viable and attractive, with LCOE values as low as USD cents 19/kWh and payback periods of 1.3-2.7 years. A key outcome of the simulations is that HOMER consistently sized PV systems to produce more electricity than actual demand, ensuring reliability during low-irradiance months and generating surpluses during peak seasons. These surpluses can be directed toward battery storage, grid export, or productive industrial uses, strengthening energy security and economic resilience. This study demonstrates that solar PV can support the three key pillars of sustainability: (i) the reduction of carbon emissions (environmental), (ii) the facilitation of cost-effective and reliable power (economic), and (iii) the expansion of energy access (social). Furthermore, the study developed a policy brief that provides recommendations for policymakers, energy developers, and investors. These include promoting public-private partnerships, implementing targeted subsidies and incentives, integrating solar energy into rural electrification strategies, and strengthening institutional frameworks for renewable energy adoption.