Browsing by Author "Katimbo, Abia"

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    Bioremediation Technology Potential for Management of Soil and Water Pollution from Anticipated Rapid Industrialization and Planned Oil and Gas Sector in Uganda: A Review
    (Journal of Environmental Protection, 2017) Kabenge, Isa; Katimbo, Abia; Kiggundu, Nicholas; Banadda, Noble
    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.
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    A critical analysis of physiochemical properties influencing pit latrine emptying and feacal sludge disposal in Kampala Slums, Uganda
    (African Journal of Environmental Science and Technology, 2016) Zziwa, Ahamada; Nabulime, Maureen N.; Kiggundu, Nicholas; Kambugu, Robert; Katimbo, Abia; Komakech, Allan J.
    Inadequate information on physiochemical properties of faecal sludge leads to inappropriate design of pit emptying devices and poor faecal sludge disposal contributing to environmental pollution. This study undertook a critical analysis of physiochemical properties of feacal sludge that influence design and performance of pit emptying devices and faecal sludge disposal for improved faecal sludge management in urban slums. The physiochemical properties determined were; Moisture content (MC), ash content (AC), total solids (TS), volatile solids (VS), nitrogen (N), phosphorous (P), potassium (K) and pH. Samples were collected from 55 unlined pits at depths of 0, 0.5, 1 and 1.5 m from pit surface. The unlined pits in this study were purposively selected from slums in Kampala. A sample of 300 g was sucked from each depth using a manual sampling tool and emptied into a plastic container. The container was then wrapped in a black plastic bag and transported in cooler boxes to the lab for analysis. The properties were subjected to Principal Component Analysis to isolate the critical parameters that affect pit emptying and faecal sludge disposal. The mean results were: MC of 86 ± 8.37%; TS of 0.14 ± 0.08 g/g wet sample; VS of 0.73 ± 0.32 g/g dry sample; pH of 8.0 ± 1.5; AC of 0.35± 0.18 g/g dry sample; TN of 3.5 ± 0.08%; K of 2.2± 0.13% and P of 1.4± 0.05%. It was concluded that physiochemical properties in Ugandan pits are comparable to those of global pits except for the acidic conditions at top surface in some pits, and higher moisture content in pits due to the high water table. PCA results showed that moisture content and total solids affected pit emptying techniques while fractional content of N, P and pH affect most choice of faecal sludge disposal technique.
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    Potential of densification of mango waste and effect of binders on produced briquettes
    (Agricultural Engineering International: CIGR Journal, 2014) Katimbo, Abia; Kiggundu, Nicholas; Kizito, Simon; Kivumbi, Hussein B.; Tumutegyereize, Peter
    In Uganda, agro-processing of fruits produces large volumes of agricultural wastes, much of which are not utilized but disposed in the landfill. This study explored the possibility of producing biomass briquettes from mango waste (seed covers) that could be used for energy supply in small factories and for domestic cooking. Mangoes were selected because of their abundance throughout the country and its high fiber content which is a good property for a raw material for briquetting. Dried mango seed covers were crushed to particles of size 2 mm and bonded with three different binders; starch, starch-clay soil, and starch-red soil. The best mixing ratios for briquettes were; 4:1 (seed-cover: starch), 9:2:1 (seed cover: starch: clay soil), and 16:4:1 (seed-cover: starch: red soil). The formed briquettes were subjected to several standard methods to verify their suitability as fuels. The briquette properties tested were moisture content, volatile matter, ash content, fixed carbon content, calorific value, compressive strength, and gas emissions. Results showed that briquettes bonded with only starch had higher fuel properties (p≤0.05) with low: moisture content (11.9%), volatile matter (16.0%), ash content (2.8%) and emissions (0.178% CO, 0.0021% (CH)X , 1.14% CO2 and no NOx); higher fixed carbon (69.3%), breaking strength (maximum force, 34 N and compressive stress, 273 N/mm2) and calorific values (16,140 kJ/kg) compared to starch-red soil and starch-clay soil briquettes. But after a linear regression analysis, results further showed that maximum force (R2 = 0.636) and ash content (R2 = 0.520) were good indicators of energy content of a particular briquette. However, more research is needed on using other binder types rather than cassava starch which is considered as food.
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    Rainwater harvesting knowledge and practice for agricultural production in a changing climate: A review from Uganda’s perspective
    (Agricultural Engineering International, 2018) Kiggundu, Nicholas; Wanyama, Joshua; Mfitumukiza, David; Twinomuhangi, Revocatus; Barasa, Bernard; Katimbo, Abia; Birungi Kyazze, Florence
    With a changing climate in Uganda, rainfall distribution patterns have become more irregular over time and space. Excess water during rainy season is causing runoff, soil erosion, nutrient depletion and crop damage which reduces the productive capacity of land, while on the other hand, prolonged droughts during the crop growing period have become common occurrences. Additionally, pastoralists lose livestock during the dry period each year in the Cattle Corridor of Uganda due to water shortage and lack of forage. It thus remains difficult to achieve the agricultural development targets identified in the National Development Plan for Uganda, without addressing regular incidences of adverse impacts of climate change. Currently there are no well explained approaches which can contribute to adoption of technologies like rainwater management systems which are crucial in enhancing crop yields and livestock production during periods of water shortage. The overarching objective of this paper was to carry out an assessment of the status, performance, and scope for improving rainwater harvesting (RWH) for small-scale agriculture under local conditions. Accordingly, research gaps in RWH technologies were identified and documented to inform future studies. The research was carried out in the semi-arid areas of Nakasongola, Rakai, and Hoima Districts characterized by crop-livestock dependent livelihoods. Findings show that RWH technologies could enable smallholder farmers and agro-pastoralists to become more resilient to increasing climate variability and climate change by conserving soil and water thus increasing food production and enhancing food security. Small-scale irrigation systems have enabled farmers to adapt to drought challenges by enhancing crop yields and allowed farmers to target for higher market prices usually associated with the effects of drought. However, there are challenges including threats to sustainability of such established systems because of lack of community participation in systems’ monitoring and maintenances, and vandalism, and some systems require high investment costs.