Only 42% of Uganda’s population has access to electricity. The population continues to use firewood and charcoal as a source of energy, which leads to depletion of forests thus to climate change. The purpose of this ...Only 42% of Uganda’s population has access to electricity. The population continues to use firewood and charcoal as a source of energy, which leads to depletion of forests thus to climate change. The purpose of this study was to assess the potential of biogas production from jackfruit waste, banana peels, and pineapple peels when co-digested with cow dung as an alternative energy source. Substrates for each waste were co-digested with varying proportions (0%, 25%, and 50%) of cow dung using laboratory-scale 250 mL anaerobic digestors. The total biogas generation for jackfruit waste, banana peels, and pineapple peels after 30 days of anaerobic digestion was 82.3, 189, and 262 mL, respectively. When jack fruit waste, pineapple peels and banana peels were co-digested with 25% cow dung, the total amount of biogas produced increased by a factor of two and three, respectively. However, 50% of cow dung only significantly (p ≤ 0.05) improved for jack fruit waste by two folds. Therefore, the results indicated that jackfruit waste, banana and pineapple peels can be used for biogas production to augment energy supply. .展开更多
This comprehensive review focuses on the performance of solar dryers, with a specific emphasis on their structural shape and orientation. Researchers have extensively examined these design parameters, often employing ...This comprehensive review focuses on the performance of solar dryers, with a specific emphasis on their structural shape and orientation. Researchers have extensively examined these design parameters, often employing Computational Fluid Dynamics (CFD) to assess thermal attributes and predict temperature distribution, airflow patterns, and temperature profiles within the structures. Geographical location significantly influences solar dryer shape preferences, with the parabolic shape finding favor in tropical regions for its superior solar radiation capture and storm resistance, while even-span and Quonset shapes are popular elsewhere. Solar dryer orientation is another crucial factor, with east-west alignment consistently proving optimal due to its ability to maximize year-round solar radiation absorption and, consequently, enhance drying efficiency. Economic considerations, however, fall beyond the scope of this review, which predominantly focuses on thermal aspects. This investigation reveals diverse global preferences for solar dryer shapes and orientation, highlighting the necessity of considering geographical factors in design choices. While CFD and shape/orientation dynamics have provided valuable insights, there remains room for future research to expand into transient state simulations under various conditions, contributing to a more comprehensive understanding of solar dryer performance. Such insights promise to promote sustainable and efficient drying processes, benefitting agricultural and drying applications across the globe.展开更多
Oil exploitation in many African countries is associated with litigation and conflicts to water and soil pollution. It is because of inadequate planning for management of oil spills and industrial effluents in environ...Oil exploitation in many African countries is associated with litigation and conflicts to water and soil pollution. It is because of inadequate planning for management of oil spills and industrial effluents in environmentally sustainable manner. Uganda’s natural resources such as soils and water bodies are threatened by contamination due to rapid industrialization and rural-urban migration in established Industrial Business Parks and planned oil and gas production at Albertine Graben Region. The low level of compliance to industrial effluents discharge standards relevant to specific environmental receptors and activities within oil and gas sector development pose a big question of how to sustain the biodiversity and natural resource management. Experiences from elsewhere have shown bioremediation as a viable and proven option to provide potentially manageable solutions to resulting pollution as a substitute to modern well-known remediation methods, for it is relatively cheaper, more efficient and minimal toxic byproducts after treatment. The most used bioremediation agents in different studies reviewed are bacterial species especially Pseudomonas and Bacillus, followed by Aspergillus a fungi species, microalgae and aquatic plants such as duckweed, macrophytes and pteridophytes. Regardless of the waste produced in either oil and gas sector or industries, these agents have shown greater biodegradation rates. Pseudomonas sp. has a degradation efficiency of oil compounds ranging from 90% - 100%, and Aspergillus sp. 75% - 95%. Some aquatic plants can thrive in created wetlands with relatively still water such as Phragmites australis which can degrade hydrocarbons especially Aromatic compounds with benzene ring up to 95%. It can thrive in salty water with high pH range of 4.8 - 8.2. With industrial wastewater, algae is the most dominant with the degradation rates varying from 65% -100% and bacteria at 70% - 90%. Most of the reported results are in the developed country context. In developing countries, duckweed is reported as the commonest aquatic plant in wastewater treatment for removal of heavy metals because it is more tolerant to a wide range of environmental conditions and produce biomass faster. It has a removal rate of heavy metals between 90% and 100%. Basing on literature data analysis, bacteria are more suitable for treating water from oil pollution using Pseudomonas sp. Phragmites australis is suited for cleaning up oil in both water and soil. Duckweed is the best in treating water polluted with industrial effluents. This paper presents the different bioremediation methods that Uganda can potentially apply to mitigate the increased risk of environmental pollutions from planned industrialization and oil and gas development in the Albertine Graben Region.展开更多
Reference evapotranspiration is very important parameter in the hydrological, agricultural and environmental studies and is accurately estimated by the FAO Penman-Monteith equation (FAO-PM) under different climatic co...Reference evapotranspiration is very important parameter in the hydrological, agricultural and environmental studies and is accurately estimated by the FAO Penman-Monteith equation (FAO-PM) under different climatic conditions. However, due to data requirement of the FAO-PM equation, there is a need to investigate the applicability of alternative ETo equations under limited data. The objectives of this study were to evaluate twelve mass transfer based reference evapotranspiration equations and determine the impact of ETo equation on long term water management sustainability in Tanzania and Kenya. The results showed that the Albrecht, Brockamp-Wenner, Dalto, Meyer, Rohwer and Oudin ETo equations systematically overestimated the daily ETo at all weather stations with relative errors that varied from 34% to 94% relative to the FAO-PM ETo estimates. The Penman, Mahringer, Trabert, and the Romanenko equations performed best across Tanzania and the South Western Kenya with root mean squared errors ranging from 0.98 to 1.48 mm/day, which are relatively high and mean bias error (MBE) varying from -0.33 to 0.02 mm/day and the absolute mean error (AME) from 0.79 to 1.16 mm/day. For sustainable water management, the Trabert equation could be adopted at Songea, the Mahringer equation at Tabora, the Dalton and/or the Rohwer equations at Eldoret, the Romanenko equation at Dodoma, Songea and Eldoret. However, regional calibration of the most performing equation could improve water management at regional level.展开更多
Greenhouse gases(GHGs)from agriculture in Africa are among the world’s fastest-growing emissions,with the livestock sector as the primary contributor.However,the methods for quantifying these emissions rely on manual...Greenhouse gases(GHGs)from agriculture in Africa are among the world’s fastest-growing emissions,with the livestock sector as the primary contributor.However,the methods for quantifying these emissions rely on manual and outdated data collection and processing approaches.Therefore,there is a need to develop more accurate and efficient methods of quantifying GHGs from livestock.This research developed a remote sensing and Artificial Intelligence(AI)based approach to quantify GHG emissions from cattle in the Kisombwa Ranching Scheme in Mubende District,central Uganda.We trained a deep learning algorithm,You Only Look Once(YOLO)v4,to detect cattle from the Unmanned Aerial Vehicle(UAV)images of the study area and applied the Simple Online Real-time Tracker(SORT)algo-rithm for automated counting.Methane(CH_(4))and Nitrous Oxide(N_(2)O)emissions from manure management and enteric fermentation were estimated using the number of cattle and the Tier 1 guidelines from the Intergov-ernmental Panel on Climate Change(IPCC).The total estimated emissions were 321,121.34 kg carbon dioxide equivalent(CO_(2)eq)per year,with CH_(4) at 282,282.96 kg CO_(2)eq per year(88%)and N_(2)O at 38,838.38 kg CO_(2)eq per year(12%).Enteric fermentation contributed the highest emissions,about 99%of the total CH_(4) emissions and 87% of the total GHGs.The proposed remote sensing and AI-driven method achieved an average F1 score of 88.9%,average precision of 97%,and average recall of 82.9% on the testing set of images.Therefore,these research findings demonstrate that remote sensing and AI are a more potent and efficient approach to upscale quantifying and reporting animal population and livestock GHG emissions for sustainable agriculture and climate change mitigation.展开更多
In this study,an integrated approach incorporating Remote Sensing(RS),Geographical Information System(GIS),local meteorological weather stations’data and NASA’s virtual meteorological stations’data were used to qua...In this study,an integrated approach incorporating Remote Sensing(RS),Geographical Information System(GIS),local meteorological weather stations’data and NASA’s virtual meteorological stations’data were used to quantify Grain Amaranth(GA)water requirements in Uganda.Penman-Monieth method within CropWAT8 model and Surface Energy Balance Algorithm for Land(SEBAL)Model was used to quantify the evapotranspiration.Normalized Difference Vegetation Index(NDVI),daily spatial distribution of Evapotranspiration(ET),Land Surface Temperature(LST)and surface albedo were extracted from satellite imagery.The ratio of effective rainfall(Pe)to Potential Evapotranspiration(PET)–(Pe/PET)and time series for NDVI were computed to determine the growth stage of GA in different areas.The GA water demand was the highest in Karamoja sub-region(467.5 mm/season)and the lowest in Tororo(174.1 mm/season).The growing season for GA in most areas of Uganda was from March to December.Estimation of evapotranspiration in Karamoja sub-region with SEBAL model corresponded to the NDVI extracted,especially for highly vegetated areas.CROPWAT indicated that if GA was planted during the late September and early October in Karamoja sub-region,despite the decreasing moisture levels,the crop could have sufficient water supply during emergence to maturity.The ability to utilize low available moisture levels makes GA a potential crop to bridge the gap(due to the elongated drought)for the food production cycle in Karamoja sub-region.展开更多
Many growing cities of Sub-Saharan Africa(SSA)are marred by the inefficient collection,management,disposal and reuse of organic waste.The purpose of this study was to review and compare the energy recovery potential a...Many growing cities of Sub-Saharan Africa(SSA)are marred by the inefficient collection,management,disposal and reuse of organic waste.The purpose of this study was to review and compare the energy recovery potential as well as bio-fertilizer perspective,from the organic waste volumes generated in SSA countries.Based on computations made with a literature review,we find that the amount of organic wastes varies across countries translating to differences in the energy and bio-fertilizer production potentials across countries.Organic wastes generated in SSA can potentially generate about 133 million GWh of energy per year.The organic waste to bio-fertilizer production potentials range from 11.08 million tons to 306.26 million tons annually.Ghana has the highest energy and bio-fertilizer potential among the SSA countries with a total per capita of 630 MWh/year and 306.26 million tons,respectively.The challenges and technical considerations for energy and bio-fertilizer approaches in the management of organic waste in SSA have also been discussed.This study is of help to the readers and strategic decision makers in understanding the contribution of bioenergy and bio-fertilizer to achieving sustainable development goals,namely,7(Affordable and Clean Energy)and 13(Climate Action)in SSA.展开更多
Raw biochar can be enriched with nutrients from digestates through adsorption producing nutrient-enriched biochar.The nutrient-enriched biochar can be used as a soil amendment to support sustainable agriculture.This s...Raw biochar can be enriched with nutrients from digestates through adsorption producing nutrient-enriched biochar.The nutrient-enriched biochar can be used as a soil amendment to support sustainable agriculture.This study assessed the effect of adsorbent dose and contact time on the jackfruit waste biochar adsorption of essential nutrients of nitrogen,phosphors and potassium from the digestate.Response surface methodology(RSM)using central composite design(CCD)was utilized to optimize the adsorbent dose and contact time during the adsorption process.An adsorbent dose of 20–70 mg/g and contact time range of 48–120 h were used in this study.The optimal adsorbent dose and contact time were found to be 20 mg/g and 114.6 h,respectively.The corresponding optimum nitrogen,phosphorus and potassium adsorbed were 17.44,20.94,and 21.36 mg/g,respectively.Models for the prediction of these values for nitrogen,phosphorus and potassium had R2 values of 0.9801,0.9804 and 0.9843,respectively,and non-significant lack of fit(p<0.05).This indicates the suitability of the models in predicting the adsorption conditions of adsorbent dose and contact time to produce high-quality nutrient-enriched biochar.展开更多
文摘Only 42% of Uganda’s population has access to electricity. The population continues to use firewood and charcoal as a source of energy, which leads to depletion of forests thus to climate change. The purpose of this study was to assess the potential of biogas production from jackfruit waste, banana peels, and pineapple peels when co-digested with cow dung as an alternative energy source. Substrates for each waste were co-digested with varying proportions (0%, 25%, and 50%) of cow dung using laboratory-scale 250 mL anaerobic digestors. The total biogas generation for jackfruit waste, banana peels, and pineapple peels after 30 days of anaerobic digestion was 82.3, 189, and 262 mL, respectively. When jack fruit waste, pineapple peels and banana peels were co-digested with 25% cow dung, the total amount of biogas produced increased by a factor of two and three, respectively. However, 50% of cow dung only significantly (p ≤ 0.05) improved for jack fruit waste by two folds. Therefore, the results indicated that jackfruit waste, banana and pineapple peels can be used for biogas production to augment energy supply. .
文摘This comprehensive review focuses on the performance of solar dryers, with a specific emphasis on their structural shape and orientation. Researchers have extensively examined these design parameters, often employing Computational Fluid Dynamics (CFD) to assess thermal attributes and predict temperature distribution, airflow patterns, and temperature profiles within the structures. Geographical location significantly influences solar dryer shape preferences, with the parabolic shape finding favor in tropical regions for its superior solar radiation capture and storm resistance, while even-span and Quonset shapes are popular elsewhere. Solar dryer orientation is another crucial factor, with east-west alignment consistently proving optimal due to its ability to maximize year-round solar radiation absorption and, consequently, enhance drying efficiency. Economic considerations, however, fall beyond the scope of this review, which predominantly focuses on thermal aspects. This investigation reveals diverse global preferences for solar dryer shapes and orientation, highlighting the necessity of considering geographical factors in design choices. While CFD and shape/orientation dynamics have provided valuable insights, there remains room for future research to expand into transient state simulations under various conditions, contributing to a more comprehensive understanding of solar dryer performance. Such insights promise to promote sustainable and efficient drying processes, benefitting agricultural and drying applications across the globe.
文摘Oil exploitation in many African countries is associated with litigation and conflicts to water and soil pollution. It is because of inadequate planning for management of oil spills and industrial effluents in environmentally sustainable manner. Uganda’s natural resources such as soils and water bodies are threatened by contamination due to rapid industrialization and rural-urban migration in established Industrial Business Parks and planned oil and gas production at Albertine Graben Region. The low level of compliance to industrial effluents discharge standards relevant to specific environmental receptors and activities within oil and gas sector development pose a big question of how to sustain the biodiversity and natural resource management. Experiences from elsewhere have shown bioremediation as a viable and proven option to provide potentially manageable solutions to resulting pollution as a substitute to modern well-known remediation methods, for it is relatively cheaper, more efficient and minimal toxic byproducts after treatment. The most used bioremediation agents in different studies reviewed are bacterial species especially Pseudomonas and Bacillus, followed by Aspergillus a fungi species, microalgae and aquatic plants such as duckweed, macrophytes and pteridophytes. Regardless of the waste produced in either oil and gas sector or industries, these agents have shown greater biodegradation rates. Pseudomonas sp. has a degradation efficiency of oil compounds ranging from 90% - 100%, and Aspergillus sp. 75% - 95%. Some aquatic plants can thrive in created wetlands with relatively still water such as Phragmites australis which can degrade hydrocarbons especially Aromatic compounds with benzene ring up to 95%. It can thrive in salty water with high pH range of 4.8 - 8.2. With industrial wastewater, algae is the most dominant with the degradation rates varying from 65% -100% and bacteria at 70% - 90%. Most of the reported results are in the developed country context. In developing countries, duckweed is reported as the commonest aquatic plant in wastewater treatment for removal of heavy metals because it is more tolerant to a wide range of environmental conditions and produce biomass faster. It has a removal rate of heavy metals between 90% and 100%. Basing on literature data analysis, bacteria are more suitable for treating water from oil pollution using Pseudomonas sp. Phragmites australis is suited for cleaning up oil in both water and soil. Duckweed is the best in treating water polluted with industrial effluents. This paper presents the different bioremediation methods that Uganda can potentially apply to mitigate the increased risk of environmental pollutions from planned industrialization and oil and gas development in the Albertine Graben Region.
文摘Reference evapotranspiration is very important parameter in the hydrological, agricultural and environmental studies and is accurately estimated by the FAO Penman-Monteith equation (FAO-PM) under different climatic conditions. However, due to data requirement of the FAO-PM equation, there is a need to investigate the applicability of alternative ETo equations under limited data. The objectives of this study were to evaluate twelve mass transfer based reference evapotranspiration equations and determine the impact of ETo equation on long term water management sustainability in Tanzania and Kenya. The results showed that the Albrecht, Brockamp-Wenner, Dalto, Meyer, Rohwer and Oudin ETo equations systematically overestimated the daily ETo at all weather stations with relative errors that varied from 34% to 94% relative to the FAO-PM ETo estimates. The Penman, Mahringer, Trabert, and the Romanenko equations performed best across Tanzania and the South Western Kenya with root mean squared errors ranging from 0.98 to 1.48 mm/day, which are relatively high and mean bias error (MBE) varying from -0.33 to 0.02 mm/day and the absolute mean error (AME) from 0.79 to 1.16 mm/day. For sustainable water management, the Trabert equation could be adopted at Songea, the Mahringer equation at Tabora, the Dalton and/or the Rohwer equations at Eldoret, the Romanenko equation at Dodoma, Songea and Eldoret. However, regional calibration of the most performing equation could improve water management at regional level.
基金funded by the Regional Universities Forum for Ca-pacity Building in Agriculture(RUFORUM)and the Global Research Alliance on Agricultural Greenhouse Gases(GRA)under project ID:RU/2020/GRG/06.
文摘Greenhouse gases(GHGs)from agriculture in Africa are among the world’s fastest-growing emissions,with the livestock sector as the primary contributor.However,the methods for quantifying these emissions rely on manual and outdated data collection and processing approaches.Therefore,there is a need to develop more accurate and efficient methods of quantifying GHGs from livestock.This research developed a remote sensing and Artificial Intelligence(AI)based approach to quantify GHG emissions from cattle in the Kisombwa Ranching Scheme in Mubende District,central Uganda.We trained a deep learning algorithm,You Only Look Once(YOLO)v4,to detect cattle from the Unmanned Aerial Vehicle(UAV)images of the study area and applied the Simple Online Real-time Tracker(SORT)algo-rithm for automated counting.Methane(CH_(4))and Nitrous Oxide(N_(2)O)emissions from manure management and enteric fermentation were estimated using the number of cattle and the Tier 1 guidelines from the Intergov-ernmental Panel on Climate Change(IPCC).The total estimated emissions were 321,121.34 kg carbon dioxide equivalent(CO_(2)eq)per year,with CH_(4) at 282,282.96 kg CO_(2)eq per year(88%)and N_(2)O at 38,838.38 kg CO_(2)eq per year(12%).Enteric fermentation contributed the highest emissions,about 99%of the total CH_(4) emissions and 87% of the total GHGs.The proposed remote sensing and AI-driven method achieved an average F1 score of 88.9%,average precision of 97%,and average recall of 82.9% on the testing set of images.Therefore,these research findings demonstrate that remote sensing and AI are a more potent and efficient approach to upscale quantifying and reporting animal population and livestock GHG emissions for sustainable agriculture and climate change mitigation.
文摘In this study,an integrated approach incorporating Remote Sensing(RS),Geographical Information System(GIS),local meteorological weather stations’data and NASA’s virtual meteorological stations’data were used to quantify Grain Amaranth(GA)water requirements in Uganda.Penman-Monieth method within CropWAT8 model and Surface Energy Balance Algorithm for Land(SEBAL)Model was used to quantify the evapotranspiration.Normalized Difference Vegetation Index(NDVI),daily spatial distribution of Evapotranspiration(ET),Land Surface Temperature(LST)and surface albedo were extracted from satellite imagery.The ratio of effective rainfall(Pe)to Potential Evapotranspiration(PET)–(Pe/PET)and time series for NDVI were computed to determine the growth stage of GA in different areas.The GA water demand was the highest in Karamoja sub-region(467.5 mm/season)and the lowest in Tororo(174.1 mm/season).The growing season for GA in most areas of Uganda was from March to December.Estimation of evapotranspiration in Karamoja sub-region with SEBAL model corresponded to the NDVI extracted,especially for highly vegetated areas.CROPWAT indicated that if GA was planted during the late September and early October in Karamoja sub-region,despite the decreasing moisture levels,the crop could have sufficient water supply during emergence to maturity.The ability to utilize low available moisture levels makes GA a potential crop to bridge the gap(due to the elongated drought)for the food production cycle in Karamoja sub-region.
文摘Many growing cities of Sub-Saharan Africa(SSA)are marred by the inefficient collection,management,disposal and reuse of organic waste.The purpose of this study was to review and compare the energy recovery potential as well as bio-fertilizer perspective,from the organic waste volumes generated in SSA countries.Based on computations made with a literature review,we find that the amount of organic wastes varies across countries translating to differences in the energy and bio-fertilizer production potentials across countries.Organic wastes generated in SSA can potentially generate about 133 million GWh of energy per year.The organic waste to bio-fertilizer production potentials range from 11.08 million tons to 306.26 million tons annually.Ghana has the highest energy and bio-fertilizer potential among the SSA countries with a total per capita of 630 MWh/year and 306.26 million tons,respectively.The challenges and technical considerations for energy and bio-fertilizer approaches in the management of organic waste in SSA have also been discussed.This study is of help to the readers and strategic decision makers in understanding the contribution of bioenergy and bio-fertilizer to achieving sustainable development goals,namely,7(Affordable and Clean Energy)and 13(Climate Action)in SSA.
基金Funding was received from Federal Ministry of Food and Agriculture(BMLE),NO.2816PROCO04.
文摘Raw biochar can be enriched with nutrients from digestates through adsorption producing nutrient-enriched biochar.The nutrient-enriched biochar can be used as a soil amendment to support sustainable agriculture.This study assessed the effect of adsorbent dose and contact time on the jackfruit waste biochar adsorption of essential nutrients of nitrogen,phosphors and potassium from the digestate.Response surface methodology(RSM)using central composite design(CCD)was utilized to optimize the adsorbent dose and contact time during the adsorption process.An adsorbent dose of 20–70 mg/g and contact time range of 48–120 h were used in this study.The optimal adsorbent dose and contact time were found to be 20 mg/g and 114.6 h,respectively.The corresponding optimum nitrogen,phosphorus and potassium adsorbed were 17.44,20.94,and 21.36 mg/g,respectively.Models for the prediction of these values for nitrogen,phosphorus and potassium had R2 values of 0.9801,0.9804 and 0.9843,respectively,and non-significant lack of fit(p<0.05).This indicates the suitability of the models in predicting the adsorption conditions of adsorbent dose and contact time to produce high-quality nutrient-enriched biochar.
