Application of black soldier fly larvae in decentralized treatment of faecal sludge from pit latrines in informal settlements in Kampala city

Introduction: Faecal sludge management (FSM) in urban areas of low-and middle-income countries (LMICs) is not properly implemented due to inaccessibility of sanitation facilities and high faecal sludge (FS) emptying costs, amongst others. Unlike in solid waste and fresh human excreta, use of black soldier fly larvae (BSFL) in treatment of FS from pit latrines - which are the most common sanitation facilities in urban areas of LMICs - has not yet been explored. Moreover, the optimal conditions for efficient FS degradation, such as moisture content, feeding rate and larval density are not yet well known. Against this backdrop, the overarching aim of this study was to determine the effectiveness of BSFL in treating FS under different conditions of moisture content, feeding rate and larval density. Also, the quality of residue left after treatment was assessed.Methods: FS samples were collected from lined and unlined pit latrines in Bwaise I parish in Kampala, Uganda and experiments were set up to feed 10-day old larvae.Results and Discussion: The optimum feeding rate, larval density and moisture content were found to be 50 mg/larvae/day, 1.33 larvae/cm2 and 60%, respectively. The reduction efficiency at optimum conditions were 72% and 66% for FS from lined and unlined pit latrines, respectively. It was further noted that BSFL can feed on FS from pit latrines without dewatering it, hence there is no need for a dewatering unit. The properties of the residue left after treatment were within the allowable limit for use as compost except for helminth egg concentration. Thus, in informal urban settlements, BSFL can be applied for effective treatment of FS from pit latrines while generating good quality residue thereby providing an additional value chain in FSM

Transitioning of urban water distribution systems

The upgrade of urban water distribution systems (UWDS) amidst uncertain global change pressures is a challenging problem. To deal with this dilemma water utilities require approaches that enable UWDS to be transitioned at a minimal technical and socio-economic impact as uncertainties become known. A review of approaches for upgrading UWDS shows that existing cost models are skewed towards operation and maintenance costs without consideration for future transitionability. This thesis describes approaches for the sustainable transition of UWDS and their application on case studies. The thesis develops a conceptual framework for the analysis of UWDS transitions. It then develops a Socio-economic Impact Indicator (SII) framework based on Multi Criteria Decision Analysis and the Analytical Hierarchical Process to estimate impacts in an urban area due to UWDS transitions. It also develops an approach for modelling socio-technical transitions based on multinomial logistic regression. The thesis then develops an UWDS transition design approach that considers not only operation and maintenance costs (leakage and burst costs) but also transitionability and future socio-technical impacts costs. The developed approaches have been tested on case studies as proof of concept. Maximum cost saving can be realised when existing UWDS are upgraded with consideration of future UWDS transitionability

Determinants of transitions in drinking water service systems in developing economies: a case study of Uganda

Limited research has been undertaken on significant factors associated with transitions between drinking water supply systems (DWSS) ladders. In this paper, we applied panel ordered logistic multinomial logistic regression models to seven datasets of the Uganda Demographic and Health Survey (1988–2021), with the SDG6 categorical levels of DWSS (unimproved, improved and piped into dwelling) as transition levels, and various socio-economic and demographic characteristics as covariates. Sex and education level of household head, toilet facility, electricity access, size of agricultural land and wealth index are significant factors. The main implication is the need to address socio-economic disparities in developing economies. HIGHLIGHTS Sheds light on significant factors associated with transitions between drinking water supply systems ladders.; Informs the need to address socio-economic disparities to transition between drinking water service systems.; Several factors are associated with the transition of drinking water service systems.; Points to the need to address the socio-economic attribute disparity to accelerate options transitions.

Determinants of transitions in drinking water service systems in developing economies: a case study of Uganda

Limited research has been undertaken on significant factors associated with transitions between drinking water supply systems (DWSS) ladders. In this paper, we applied panel ordered logistic multinomial logistic regression models to seven datasets of the Uganda Demographic and Health Survey (1988-2021), with the SDG6 categorical levels of DWSS (unimproved, improved and piped into dwelling) as transition levels, and various socio-economic and demographic characteristics as covariates. Sex and education level of household head, toilet facility, electricity access, size of agricultural land and wealth index are significant factors. The main implication is the need to address socio-economic disparities in developing economies.</p

Impacts of climate and land use/cover change on mini-hydropower generation in River Kyambura watershed in South Western part of Uganda

This study explored the combined impacts of climate and land-use change on mini-hydropower generation in the Kyambura watershed. The soil and water assessment tool (SWAT) was used as a hydrological model whereas the statistical downscaling model (SDSM) was used to downscale meteorological data for the Kyambura watershed for the year 2050. The results show that there will be an increase in urban land by 11.89%, barren land by 25.78%, water by 0.49% and a reduction in percentage area coverage of vegetation by 38.17% by the year 2050. A 10.6 and 17.7% increase is anticipated in average annual hydropower generated by the year 2050. There is, therefore, a need to develop governing policies to regulate management practices to preserve the integrity of the watersheds and ensure the reliability of power production. HIGHLIGHTS Quantifies LULC changes within the Kyambura catchment from 1989 to 2019.; Predicts and quantifies LULC changes within the Kyambura catchment by the year 2050.; Predicts the changes in climate, stream flows and Hydropower generation within the Kyambura catchment by the year 2050.; Elucidates on the impacts of climate and Land use/cover change on mini-hydropower generation.