NRU :: Browsing by Author "Komakech, Allan John"

Browsing by Author "Komakech, Allan John"

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Assessment of a Cattle Manure Vermicomposting System Using Material Flow Analysis: A Case Study from Uganda
(Sustainability, 2019) Jjagwe, Joseph; Komakech, Allan John; Karungi, Jeninah; Amann, Arabel; Wanyama, Joshua; Lederer, Jakob
Growth in cattle population is associated with increased manure generation whose current management in low-income countries is associated with health and environmental problems as well as low utilization rates. This trend can be reversed by promoting better manure management technologies. This study assessed vermicomposting as one of the technologies to manage organic wastes, using the case study in Uganda. A vermicomposting system using cattle manure and earthworms (Eudrilus euginea) was monitored for one year with the harvesting of products (compost, earthworm biomass) after every three months. Vermicompost samples from the beginning of the experiment and after every harvest were analyzed for the following parameters: pH, ash content, volatile and total solids, nutrients N, P, K, and C. Emissions of CO2, CH4, NH3, and N2O were also measured. Material flow analysis was used to determine the flows and retention of nutrients within the system. Results showed that total solids, ash, N, P, and K content significantly increased, while contents of volatile solids and C, as well as the pH, significantly decreased over time. Of the materials that entered the vermicomposting system, 46% went to vermicompost, 2% into earthworms, and 52% was lost to the atmosphere. Substance flow analysis showed that 30% of C went to vermicompost, 69% was emitted to the atmosphere, and 2% ended up in earthworms while 75% of N was transferred to vermicompost, 7% went to earthworms, and 18% escaped into the atmosphere. The cumulative emissions were 102 g CO2 kg􀀀1 waste, 7.6 g CH4 kg􀀀1 waste, and 3.943 10􀀀5 g N2O kg􀀀1 waste on a dry basis, while NH3 was not detected throughout the measurement time. Compared to other manure management methods, vermicomposting demonstrated good potential in conserving nutrients as well as reducing greenhouse gas emissions.
Can Local Nutrient-Circularity and Erosion Control Increase Yields of Resource-Constraint Smallholder Farmers? A Case Study in Kenya and Uganda
(Journal of Cleaner Production, 2021) Amann, Arabel; Herrnegger, Mathew; Karungi, Jeninah; Komakech, Allan John; Mwanake, Hope; Schneider, Lea; Schürz, Christoph; Stecher, Gabriel; Turinawe, Alice; Zessner, Matthias; Lederer, Jakob
As many regions in sub-Saharan Africa, the border region of Kenya (KE) and Uganda (UG) has faced a declining soil fertility for decades, resulting from soil erosion, intensely managed agricultural soils due to population pressure and small inputs of mineral and organic fertilisers. With limited financial means, farmers need measures and/or technologies that effectively reduce nutrient losses or increase inputs at a low cost. In this study, four such measures are in focus, namely erosion reduction practices, vermicomposting of animal manure, collection of human urine in jerry cans and, collection of human excreta in urine-diverting dry toilets. Current soil nutrient balances in five districts in the Sio-Malaba-Malakisi River Basin and the potential of these measures to reduce the soil nutrient deficit are studied using the method of material flow analysis and the software STAN. Furthermore, crop14 nutrient-response functions are used to determine their potential impact on maize harvests. Overall, results reveal that there exists a non-negligible and exploitable potential of local resources to reduce the soil nutrient deficit, improve harvests and in turn food security of the smallholder farmers in the region. Soil nutrient deficits could be reduced by 20 — 30 %, 23 — 42 % and 9 — 15 % for nitrogen (N), phosphorus (P) and potassium (K), respectively. Subsequently, maize harvests could be increased by 8 – 40 %, depending on the applied technology and area. This research provides useful insights for agricultural extension workers, politicians and researchers alike, highlighting that simple and easily available technologies can harness similar amounts of nutrients as more complex and expensive ones if all specific technology constraints are adequately incorporated in the analyses.
Estimation of Methane Generation Based on Anaerobic Digestion and Mass Balance at Kiteezi Landfill, Kampala, Uganda
(African Journal of Environmental Science and Technology, 2015) Mboowa, Drake; Banadda, Noble; Kiggundu, Nicholas; Kabenge, Isa; Komakech, Allan John
Kiteezi landfill site is the main solid waste dumping site in Kampala City (Uganda). In this study, the generation of methane from waste at Kiteezi landfill was measured using laboratory-scale anaerobic digestion experiment and estimated using the Mass balance model. The samples were collected in the wet and dry seasons, with five replicates for each season which were processed for further experiments focused on moisture content analysis and anaerobic digestion. The moisture content analysis results showed a significant change (P < 0.05) between wet season and dry season. Also, the anaerobic digestion revealed that moisture content was a determining factor in gas generation. The average monthly methane production estimate from the mass balance model was 1.63 Gg methane/month and was comparable (within 14%) to the amount estimated by laboratory-scale anaerobic digestion experiment (1.43 Gg methane/month). It is a worthwhile undertaking to further investigate the potential of commercially producing methane from Kiteezi landfill as an alternative source of green and clean energy for urban masses.
Irrigation Development in Uganda: Constraints, Lessons Learned, and Future Perspectives
(Journal of Irrigation and Drainage Engineering, 2017) Wanyama, Joshua; Ssegane, Herbert; Kisekka, Isaya; Komakech, Allan John; Banadda, Noble; Zziwa, Ahamada; Ebong, Tobias Oker; Mutumba, Charles; Kiggundu, Nicholas; Kayizi, Ronald Kato; Mucunguzi, Dominic Banaga; Kiyimba, Florence Lubwama
Policy makers in sub-Saharan African (SSA) countries have identified irrigation as a key ingredient to boosting food security and income as well as a precursor for agricultural development. However, most SSA countries have hardly exploited their irrigation potential. The overarching aim of this paper is to critically examine factors constraining exploitation of irrigation potential in Uganda. Lessons learned from previous interventions and successes elsewhere from countries comparable to Uganda are drawn and future perspectives to guide effective irrigation planning and development are recommended. From this paper, it is evident that there is no single blanket solution to constraints of irrigation development in SSA. All strategies should be implemented in a holistic manner dictated by specific local conditions. The key to successful adoption of irrigation lies in building the national irrigation capacity, improving access to reliable water for irrigation in proximity of the farms, streamlining extension services for farmers, addressing economic aspects of irrigation, and streamlining land tenure systems and management. It is recommended to operationalize government policy on irrigation by developing national guidelines on irrigated agriculture.
Membrane fouling control in low pressure membranes: A review on pretreatment techniques for fouling abatement
(Environmental Engineering Research, 2016) Arhin, Samuel Gyebi; Banadda, Noble; Komakech, Allan John; Kabenge, Isa; Wanyama, Joshua
Conventional treatment techniques cannot meet the stringent modern water quality regulations emanating from the need to provide high quality drinking water. Therefore, a number of studies have suggested low pressure membrane filtration as a worthwhile alternative. However, a major constraint to the extensive use of this technology in low and middle income countries is the high operating and maintenance costs caused by the inherent predisposition to membrane fouling. Notwithstanding, pretreatment of feed water using techniques such as coagulation, adsorption, oxidation and bio-filtration is believed to control fouling. In this review paper, the existing scientific knowledge on membrane fouling and pretreatment techniques for controlling fouling in low pressure membranes is analyzed with the aim of providing new and valuable insights into such techniques, as well as unveiling crucial issues noteworthy for further studies. Among the techniques reviewed, coagulation was observed to be the most cost-effective and will remain the most dominant in the coming years. Although oxidants and magnetic ion exchange resins can also control fouling, the propensity of oxidants to form health treating precursors and the high economic implications of magnetic ion exchange resins will hinder their adoption in developing countries.
Nutrient recovery from pineapple waste through controlled batch and continuous vermicomposting systems
(Journal of Environmental Management, 2021) Zziwa, Ahamada; Jjagwe, Joseph; Kizito, Simon; Kabenge, Isa; Komakech, Allan John; Kayondo, Henry
The largest portion of pineapple peels and pulp generated from production points is disposed of haphazardly contributing to a number of environmental and health challenges. However, these wastes contain valuable plant nutrients that could be recovered to boost soil fertility, and increase agricultural production. This study evaluated the variation in physico-chemical parameters in batch and continuous vermicomposting systems as potential pathways for nutrient recovery from pineapple waste. The study compared the efficiency of waste reduction and nutrient recovery for batch (B), and continuous (C) vermicomposting systems during a 60-day period. The substrates were pineapple peels (PW), and cattle manure (CM) fed in a ratio of 4:1 (w/w). Control reactors were fed with 100% CM in both the feeding modes. Results indicated that waste degradation was 60%, and 54% while earthworm biomass increased by 57% and 129% for BPW, and CPW, respectively. pH significantly decreased with time in both systems. Total phosphorous increased with vermicomposting time with that of B being significantly higher than C systems. Nitrogen, potassium, and sodium significantly increased in the control experiments while the three elements significantly reduced for BPW, and CPW owing to high leachate production in the latter. The N, P, K, and C retention in vermicompost was 24.2%, 90.4%, 67.5%, 41.1%, and 32.6%, 91.2%, 79.3%, 46.1%, for BPW and CPW, respectively. Continuous systems produced higher earthworm biomass and retained more nutrients in vermicompost than batch systems, and can therefore, be recommended as better systems for pineapple waste vermicomposting.
Occurrence and survival of pathogens at different sludge depths in unlined pit latrines in Kampala slums
(Water Sa, 2017) Nabateesa, Sylivia; Zziwa, Ahamada; Kabenge, Isa; Kambugu, Robert; Wanyama, Joshua; Komakech, Allan John
Occurrence and survival of pathogens in faecal sludge was investigated in unlined pit latrines at varying depths in peri-urban areas of Kampala city, Uganda. A total of 55 unlined pit latrines, 7 private and 8 rental unlined pit latrines were sampled in the first and second phases (representing the rainy season) and 40 pits in the third phase (representing dry season), and analysed for indicator organisms and pathogens from 4 pit latrine sludge layers, at depths of 0, 0.5, 1.0 and 1.5 m, following APHA standard methods. Physico-chemical parameters of the faecal sludge were also measured. Three sampling phases were undertaken to determine the effect of seasonal variation. Results indicate that the mean temperature and pH were 25.4 ± 1.14°C and 8.0 ± 1.5, respectively; and moisture content increased with pit sludge depth, except between Depths 3 and 4. Average moisture content was 86.3 ± 3%. The measured parameters varied significantly (P > 0.05) between seasons. The mean reduction in total coliforms, thermo-tolerant coliforms, E. coli, and faecal enterococci with sludge depth was significant at all depths (P < 0.05), but the least significant difference was not significant at depth levels of 1.0 m and 1.5 m. Salmonella was only detected at the top layer of faecal sludge in 60% of Phase 2 samples and in only 20% of the samples in Phase 3. About 200–4 100 eggs/g of strongyles were found in 98% of the samples and 100–1 600 eggs/g of ascarids in 55% of the samples. Temperature, pH and moisture content did not show a significant correlation with observed reductions of indicators and pathogens. With extrapolation of the generated regression models, a pit of 8 m can be recommended for reduction of bacteria. It is recommended that protective field gear be used during pit emptying and that faecal sludge treatment should be done to reduce pathogens before disposal into the environment.
Performance Characteristics of a Cooking Stove Improved with Sawdust as an Insulation Material
(Journal of Renewable Energy, 2021) Okino, Jasper; Komakech, Allan John; Wanyama, Joshua; Ssegane, Herbert; Olomo, Elly; Omara, Timothy
In developing countries, energy demand from biomass has increased due to exponential population growth. (is has translated into voluminous quantities of wood being used. (e situation is exacerbated by the popular use of inefficient stoves with low thermal insulation, hence contributing to deforestation. In this study, the performance of a cooking stove improved with sawdust as an insulation material was assessed. An insulated fire stove prototype of 26 cm saucepan diameter was designed, constructed, and cast with sawdust and clay in a ratio of 1 :1 (as the first layer) and sawdust alone as the second layer. (e developed stove was tested using a water boiling test to establish its operating performance. (e thermal efficiency of the stove was assessed using indigenous wood fuels used in rural Uganda (Senna spectabilis, Pinus caribaea, and Eucalyptus grandis). Computational fluid dynamics was used to simulate the temperature and velocity fields within the combustion chamber and for generating temperature contours of the stove. Obtained results indicated that S. spectabilis had the highest thermal efficiency of 35.5 ± 2.5%, followed by E. grandis (25.7 ± 1.7%) and lastly P. caribaea (19.0 ± 1.2%) in the cold start phase when compared with traditional stoves. (e stove remained cold as hot air was restricted to the combustion chamber with decreasing temperature contours toward the outer wall up to the ambient temperature. (e velocity flow remained constant as the chamber was colored green throughout due to the shielding of the stove with sawdust as insulation. (e heat flux generated indicated that a thick layer of 6 cm or more could ensure good insulation, and this could be further reduced by introducing more sawdust. (e designed stove has the potential to reduce biomass consumption and emissions when compared to traditional cookstoves. (e inclusion of a chimney draught in the fire stove prototype could reduce smoke and increase thermal efficiency. Further studies should focus on minimizing the thickness of the clay-sawdust (first) layer and increasing the thickness of the sawdust layer to reduce the weight of the fire stove.
Pharmaceutical Pollution Of Water Resources In Nakivubo Wetlands And Lake Victoria, Kampala, Uganda
(Science of The Total Environment, 2020) Dalahmeh, Sahar; Björnberg, Emma; Elenström, Anna-Klara; Niwagaba, Charles B.; Komakech, Allan John
This study investigated the occurrence and removal in wastewater and water bodies in Nakivubo wetland area and Inner Murchison Bay, Lake Victoria, of common prescription and non-prescription pharmaceutically-active substances (PhACs) sold in Kampala city, Uganda. A questionnaire was sent to 20 pharmacies in Kampala, to identify the most commonly sold PhACs in the city. During two sampling campaigns, samples were collected from Bugolobi wastewater treatment plant (WWTP) influent and effluent and surface water samples from Nakivubo channel, Nakivubo wetland and Inner Murchison Bay. The concentrations of 28 PhACs, organic matter, solids and nutrients in water samples were analysed. Ciprofloxacin (antibiotic), cetirizine (anti-allergy), metformin (anti-diabetes), metronidazole (antibiotic) and omeprazole (gastric therapy) were reported by pharmacies to be the PhACs most commonly sold in the study area. Chemical analysis of water samples revealed that trimethoprim (antibiotic) and sulfamethoxazole (antibiotic) were the dominant PhACs in water from all sites except Lake Victoria. Other PhACs such as atenolol (anti-hypertensive), carbamazepine (anti-epileptic) and diclofenac (anti-inflammatory) were also found at all study sites except Lake Victoria. ∑PhACs in effluent from Bugolobi WWTP (13000–37,600 ng L−1) was higher than in the corresponding influent (4000–28,000 ng L−1), indicating poor removal of PhACs within the WWTP. ∑PhACs decreased by a factor of 2–6 between Bugolobi WWTP effluent and Nakivubo channel (5700 ng L−1), due to dilution and sorption to channel sediment, and by a factor of 1–3 between the Nakivubo channel and Nakivubo wetland (3900–5400 ng L−1), due to sorption to sediment and uptake by plants in the wetland. No detectable levels of PhACs were found in water from Lake Victoria. Overall, this investigation demonstrated that PhACs in wastewater enter Nakivubo water system. Thus, Bugolobi WWTP needs to be upgraded to improve PhACs removal from wastewater. Considering the high occurrence of antibiotics in the water system in Kampala, development and spread of antimicrobial resistance within the area should also be investigated.

Browsing by Author "Komakech, Allan John"

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