NRU :: Browsing by Author "Niwagaba, Charles B."

Browsing by Author "Niwagaba, Charles B."

Now showing 1 - 13 of 13

Assessing Ambient And Internal Environmental Conditions Of Pit Latrines In Urban Slums Of Kampala, Uganda: Effect On Performance
(Journal of Water, Sanitation and Hygiene for Development, 2017) Nakagiri, Anne; Niwagaba, Charles B.; Nyenje, Philip M.; Kulabako, Robinah K.; Tumuhairwe, John B.; Kansiime, Frank
There is increasing interest to improve the functionality and performance of pit latrines in low income urban areas. This study aimed at assessing the ambient and pit environmental conditions and their implications on the performance (smell and fly nuisance) of pit latrines. Forty-two pit latrines were investigated in urban slums of Kampala, Uganda, through field observation and measurements of ambient and pit environmental conditions. The implications were assessed using oxygen-reduction potential (ORP) and its association with smell/insect nuisances. The pit temperature (21 to 30.7 °C), pH (5.0–11.8) and ORP (−247 to 65.9 mV) were consistently, significantly different (p < 0.001) between the surface and 0.5 m depth of pit content. The conditions in most (95%) pit latrines were anoxic (ORP < +50 mV), and mainly within the acid formation range (ORP −199 to −51 mV). Most smelling pit latrines and flies were within the acid formation ORP range, with a significant association (gamma, G = 0.797, p = 0.014) between ORP and smell in clean latrines only. The results suggest that ventilation of pit latrines within urban slums was not sufficient. Additionally, cleanliness, moisture reduction and waste stabilisation could address bad smells in pit latrines, ultimately improving their usage in urban slums.
Blue Diversion: A New Approach To Sanitation In Informal Settlements
(Journal of Water, sanitation and Hygiene for Development, 2015) Larsen, Tove A.; Gebauer, Heiko; Gründl, Harald; Künzle, Rahel; Lüthi, Christoph; Messmer, Ulrike; Morgenroth, Eberhard; Niwagaba, Charles B.; Ranner, Bernhard
The sanitation concept ‘Blue Diversion’ (www.bluediversiontoilet.com) was developed as a possible answer to the sanitation crisis in urban slums. It is based on two main elements: (1) diversion of urine, feces, and water at the source as the basis for efficient resource recovery, and (2) linking different scales (family toilets and semi-centralized resource recovery). Our objective was to develop an attractive ‘grid-free’ (i.e. functioning without piped water, sewer, and electrical grid) dry urine-diverting toilet, which provides water (through recycling on-site) for flushing, personal hygiene (anal cleansing and menstrual hygiene), and hand washing. This service, including the entire sanitation value chain, should eventually be made available as a profitable business with total user fees of 5 ¢/p/d. The results presented in this paper are (1) a toilet design model, (2) the development of a new type of membrane bioreactor for treating flush and wash water, (3) main results of a geographic information system-based stochastic service model to link the family-scale toilet to a community-scale Resource Recovery Plant, and (4) a business model that yields maximum profit for the local community. We conclude that the approach is feasible, but challenging from a technical as well as an organizational point of view.
Decentralized opt 1 ions for faecal sludge management in urban slum 2 areas of Sub-Saharan Africa: A review of technologies, practices and 3 end-uses
(Resources, Conservation and Recycling, 2015) Semiyaga, Swaib; Okure, Mackay A. E.; Niwagaba, Charles B.; Katukiza, Alex Y.; Kansiime, Frank
Faecal sludge (FS), a product from on-site sanitation systems, poses a management challenge in densely populated urban slums of Sub-Saharan Africa (SSA). Currently, FS or its liquid fraction after dewatering is co-treated with sewage in conventional treatment plants. When dewatered, the solid stream is dried and stored further as the terminal treatment or is co-treated directly with organic solid wastes in composting or anaerobic digestion systems. To implement these, FS has to be collected and transported. Also, land is needed, but it is in most cases limited in slums or their vicinity. The collection and transport of FS from slums is costly due to lack of access, traffic congestion and long travel distances to treatment plants. Moreover, uncollected FS poses health risks and pollutes surface and/or ground water within slums. This review demonstrates that currently utilized technologies and practices fall short in various ways and discusses the possibility of minimizing FS management related costs, risks and pollution in urban slums by decentralized treatment and end-use. It also discusses the possible FS-derived end-products and their benefits to urban slum dwellers. Substitution of a part of natural materials (sand and clay) when building and/or biomass (firewood and charcoal) for cooking with FS derived end-products could multiply the benefits of improved sanitation to slum dwellers.
Determinants Of Households’ Cleaning Intention For Shared Toilets: Case Of 50 Slums In Kampala, Uganda
(Habitat international, 2014) Tumwebaze, Innocent K.; Niwagaba, Charles B.; Günther, Isabel; Mosler, Hans-Joachim
Cleaning shared toilets is important if users are to receive the significant health, social and economic benefits associated with having access to these facilities. However, achieving and maintaining hygienic toilets shared by several user households in urban slums is usually a challenge. This study assesses determinants of households' cleaning intention for shared toilets in Kampala, Uganda. Using a structured questionnaire for the household interviews and an observation checklist, data from 1019 users of shared toilets was collected in 50 randomly selected urban slums. Data analysis showed that most of the shared toilets are unhygienic. Less than a quarter of the shared toilets, for instance, were hygienically clean to users' satisfaction. The main cleaning intention determinants (p-value <.05) included: importance of using a clean toilet, the effort involved in cleaning the toilet, the disgust felt from using a dirty toilet, and cleaning habits. Although it is important to have access to sanitation facilities, emphasis should be placed on how to engage users to ensure that the facilities used are appropriately cleaned and maintained.
Documentation and Evaluation of EcoSan Experiences in Uganda
(DWD, 2005) Niwagaba, Charles B.; Asiimwe, Florence Akiiki
Ecological sanitation (ecosan) was introduced in Uganda as an alternative sanitation system that could solve the problems of traditional means of human excreta management namely difficult soils (rocky as well areas with high water table), need for digging new pits which is expensive and sometimes there may not be enough land for digging new pits in the case of pit latrines; high initial cost as well as high operation and maintenance costs in the case of water borne systems; and potential for contamination of ground water by both systems. Examples depicting the extent of the problem of traditional sanitation systems were twofold. The first was the 1997 hydro-geological study which showed that the veins of the Chuho water source were passing beneath the Kisoro town, suggesting a serious health risk of pit latrines in the town. The other was the difficulty of constructing pit latrines in Muhanga trading center where most toilets were collapsing due to high water table and unstable soils. Against this background, the Directorate of Water Development (DWD) started constructing ecosan toilets under the South Western Towns Water and Sanitation (SWTWS) Project, a Government of Uganda (GoU) project co-funded by the governments of Uganda and Austria. At the beginning, attempts to introduce ecosan toilets were met with resistance as people felt it was unheard of to re-use human excreta. The very first ecosan toilets were of the composting type. These were inappropriately operated since they resembled ordinary pit latrines and people did not understand and follow the correct procedures of adding carbon bulking materials. Consequently, the toilets were abandoned in favour of urine diverting dehydration toilets. In addition to Austria Government, more other donors namely Sida and DFID are now supporting ecosan activities in Uganda. Over the last 3 years, DWD hly that there are approximately 5000 ecosan toilets in Uganda. This study ‘the documentation and evaluation of ecosan experiences in Uganda’ was commissioned by DWD. The objective of this study was to collect, document and evaluate people’s experiences on ecosan; and to use that information to come up with preliminary do’s and don’t’s in ecosan implementation in Uganda. The study was performed in twelve (12) districts in Uganda namely, Kisoro, Kabale, Ntungamo, Rukungiri, Bushenyi, Mbarara, Masaka, Rakai, Wakiso, Mpigi, Soroti and Arua.
Enhancing Faecal Sludge Dewaterability and End use By Conditioning With Sawdust and Charcoal Dust
(Environmental Technology, 2018) Semiyaga, Swaib; Okure, Mackay A. E.; Niwagaba, Charles B.; Nyenje, Philip M.; Kansiime, Frank
Faecal sludge (FS) treatment in urban slums of low-income countries of sub-Saharan Africa is poor or non-existent. FS contains over 90% water and therefore dewatering it within slums decreases transport costs, facilitates local treatment and end-use. This study was designed to enhance the dewatering efficiency of FS, using two locally available physical conditioners (sawdust and charcoal dust), each applied at dosages of 0%, 25%, 50%, 75%, 100% and 125% TS. The optimum dosage for both conditioners occurred at 50% and 75% for cake moisture content and capillary suction time, respectively. The dewatering rate improved by 14.3% and 15.8%, whereas dewatering extent (% cake solids) improved by 22.9% and 35.7%, for sawdust and charcoal dust, respectively. The dewatering in FS conditioned with sawdust and charcoal dust was mainly governed by absorption and permeation (porosity), respectively. The FS calorific value improved (from 11.4 MJ kg−1) by 42% and 49% with 50% TS dosage of sawdust and charcoal dust, respectively. The FS structure also became porous after dewatering which hastens the subsequent drying and/or composting processes. Due to comparable performance in dewatering, sawdust or charcoal dust, whichever is locally available, is recommended to treat FS in low-income urban slum settlements.
Evaluation Of The Efficiency And Benefits Of A Pilot Scaled Decentralized Faecal Sludge Treatment System In Kampala
(International Journal of Scientific & Engineering Research, 2019) Otaka, George; Okullo, Aldo; Niwagaba, Charles B.; Kulabako, Robinah N.; Katukiza, Alex Y.
Many peri-urban cities of Sub-Saharan Africa are overwhelmed with overloading the existing centralised wastewater treatment plants and high capital costs of operations and maintenance. In this work, a pilot decentralized faecal sludge treatment system (DEFASTS) was constructed in Kampala for assessing the performance and potential benefits of the treatment system. It consisted of a sedimentation tank, 2 m3, where liquid overflowed sequentially through anaerobic baffled reactor and anaerobic filter. Effluent was polished by a Cyperus papyrus planted gravel filter. The system was loaded daily with 0.5m3/day of mixed raw faecal sludge from both septic tanks and pit latrines operated with a total retention time of 12.52 days. Monitored parameters were; Chemical Oxygen Demand, five-day Biochemical Oxygen Demand total suspended solids pH, temperature, total phosphorus, total nitrogen faecal coliforms total volatile solids and ash content. Results obtained were 95.7±24 %, 96.4±1.9%, 96.8±1.8%, 78.4± 24.2%, 76.6±29.8% and 99 ±1.6% respectively.
Mapping Out The Solid Waste Generation And Collection Models: The Case Of Kampala City
(Journal of the Air & Waste Management Association, 2015) Kinobe, Joel R.; Niwagaba, Charles B.; Gebresenbet, Girma; Komakech, Allan J.; Vinnerås, Björn
This paper presents a mapping of the waste collection systems in Kampala city, using geographical information system (GIS) ArcGIS mapping software. It discusses the existing models of waste collection to the final disposal destinations. It was found that food and yard wastes constitute 92.7% of the waste generated in Kampala. Recyclables and other special wastes constitute only 7.3% of the total waste, mainly because of the increased level of reuse and recycling activities. The generation rate of solid wastes was on average, 582, 169, 105, and 90 tons/day from poor areas, upscale wealthier areas, business centers, and market areas respectively. This tonnage of waste was collected, transported, and disposed of at the city landfill. The study found that in total, residential areas of poor people generate more waste than other categories stated earlier, mainly because of their large populations. In total, there were 133 unofficial temporary storage sites acknowledged by Kampala Capital City Authority (KCCA) but not formally designated, 59 illegal dump sites, and 35 officially recognized temporary waste storage locations. This paper presents large-scale data that can help with understanding the collection models and their influence on solid waste management in Kampala city, which could be used for similar cities in developing countries.
Optimisation of Centrifuge Operating Conditions for Dewatering Physically Conditioned Faecal Sludge from Urban
(Environmental Technology & Innovation, 2017) Semiyaga, Swaib; Niwagaba, Charles B.; Nyenje, Philip M.; Kansiime, Frank
Decentralised faecal sludge (FS) dewatering in urban slums using centrifugation technology has potential to reduce public health risks and environmental pollution caused by indiscriminate disposal of untreated FS. A laboratory-scale centrifuge was applied to dewater FS from lined pit latrines, conditioned with sawdust and charcoal dust. Response surface methodology and central composite design were used to construct and model relationships between independent variables (FS volume, centrifugation time and speed) and the dependent variable (per cent cake solids) for unconditioned and conditioned (sawdust and charcoal dust) FS. The results demonstrated that the centrifugation technology can yield more per cent cake solids at reduced speeds when physically conditioned. Rotational speed was a significant parameter for unconditioned (original) () and charcoal dust conditioned FS (). Significant parameters for sawdust conditioned FS were speed () and quadratic effect of time (). An optimal centrifugation time of 20 minutes and centrifugation container volume of 50 mL at 70–80% full of FS for conditioned FS were obtained. The centrifugation speeds tested in this paper provide critical information for proto-type design of a hand-powered centrifuge, the operating conditions and its subsequent set-up. This can serve as an option for dewatering FS from commonly used sanitation facilities in urban slums, thereby enabling decentralised treatment to reduce costs of FS management and support resource recovery at the source.
Performance Of Pit Latrines In Urban Poor Areas: A Case Of Kampala, Uganda
(Habitat international, 2015) Nakagiri, Anne; Kulabako, Robinah N.; Nyenje, Philip M.; Tumuhairwe, John B.; Niwagaba, Charles B.; Kansiime, Frank
In many urban poor areas of Sub-Saharan Africa (SSA), demand for human excreta disposal is met, predominantly by pit latrines. This study aimed at determining the status of pit latrines (design, construction, operation and maintenance) and its influence on latrine performance (filling, smell and insect nuisance). The study was conducted on 130 pit latrines in typical urban poor areas of Kampala, Uganda. Data on design, construction, usage, operation and performance of the pit latrines was collected by interviews, observations and measurements; and analysed by descriptive statistics, bi-variate analysis and logistic regression. Results showed that the level of pit content was predicted by rain or storm water entry, terrain, cleaning before or after use and number of households using the latrine. Smell was predicted by cleanliness, stance length, superstructure material and whether the latrine was private or public. The predictor of presence of flies was the superstructure material. To improve the performance of pit latrines in urban poor areas, researchers and practitioners should develop local latrine design standards (dimensions, construction materials and number of users) and cleaning guidelines for local policy makers to implement.
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.
Structured Approach for Comparison of Treatment Options for Nutrient-Recovery From Fecal Sludge
(Frontiers in Environmental Science, 2020) McConville, Jennifer R.; Kvarnström, Elisabeth; Nordin, Annika C.; Jönsson, Håkan; Niwagaba, Charles B.
The aim of this study is to present a structured approach for comparing possible nutrient-recovery fecal sludge (FS) treatment systems in order to support transparent decision-making. The approach uses a multi-dimensional sustainability assessment of treatment technologies for nutrient recovery from FS, using a typical case of Kampala City, Uganda. A synthesized list of 22 treatment technologies was prepared from literature. This list included wastewater treatment technologies, which could be adapted to treat fecal sludge, and established fecal sludge treatment technologies that are available or potentially applicable in Kampala. Based on the local situation, the list was reduced to eight possible options, which were carried forward into a multi-dimensional sustainability assessment that incorporated input of stakeholders. The technologies included in the final assessment were optimization of the existing system, lactic acid fermentation (LAF), composting, vermicomposting, Black-Soldier Fly (BSF) composting, ammonia treatment, alkaline stabilization and solar drying. Optimization of the existing system performed well against the set criteria and is a recommended short-term solution. This will require e.g., adding narrower screens to remove more trash from the incoming sludge and respecting storage times prior to selling the sludge. To maximize the agricultural value of the recovered product, while respecting the need for safe reuse, a combination of technologies becomes relevant; the use of a combination of BSF, and subsequent ammonia or alkaline treatment of the remaining organic fraction would allow for maximized safe nutrient recovery and can be the aim for long-term sanitation planning in Kampala. The results of this process provide supporting information for a discussion of trade-offs between stakeholder groups as part of a decision-making process within a larger planning context.
A Value Proposition: Resource Recovery From Faecal Sludge—Can It Be The Driver For Improved Sanitation?
(Resources, Conservation and Recycling, 2014) Diener, Stefan; Semiyaga, Swaib; Niwagaba, Charles B.; Muspratt, Ashley Murray; Gning, Jean Birane; Mbéguéré, Mbaye; Ennin, Joseph Effah; Zurbrugg, Christian; Strande, Linda
There is currently a lack of access to affordable sanitation in urban areas of Sub-Saharan Africa. This study evaluated the potential for resource recovery from innovative faecal sludge treatment processes to generate a profit that could help sustain the sanitation service chain. A total of 242 interviews were conducted in Accra, Ghana; Dakar, Senegal; and Kampala, Uganda to compare markets in different cultural and regional contexts. Products identified to have potential market value include dry sludge as a fuel for combustion, biogas from anaerobic digestion, protein derived from sludge processing as animal feed, sludge as a component in building materials, and sludge as a soil conditioner. The market demand and potential revenue varied from city to city based on factors such as sludge characteristics, existing markets, local and regional industrial sectors, subsidies, and locally available materials. Use as a soil conditioner, which has been the most common end use of treated sludge, was not as profitable as other end uses. These findings should help policy and decision makers of sanitation service provision to design financially viable management systems based on resource recovery options.

Browsing by Author "Niwagaba, Charles B."

Results Per Page

Sort Options