Browsing by Author "Mpagi Kalibbala, Herbert"

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    Development and appraisal of hand wash-wastewater treatment system for water recycling as a resilient response to COVID-19
    (Elsevier, 2021-07-28) Olupot, Peter Wilberforce; Menya, Emmanuel; Jjagwe, Joseph; Wakatuntu, Joel; Kavuma, Tonny; Wabwire, Andrew; Kavuma, Steven; Okodi Mcmondo, Samuel; Nabuuma, Betty; Mpagi Kalibbala, Herbert
    In this work, results from characterization of handwashing wastewater from selected stations in Kampala City, Uganda, revealed that handwashing wastewater did not meet permissible international standards for wastewater discharge to the environment. The ratio of BOD5 to COD of ˂ 0.5 implied that handwashing wastewater was not amenable to biological treatment processes. Turbidity of ˃ 50 NTU pointed to the need for a roughing filter prior to slow sand filtration. Subsequently, a handwashing wastewater treatment system consisting of selected particle sizes of silica sand, zeolite, and granular activated carbon as filtration and/or adsorption media was developed and assessed for performance towards amelioration of the physicochemical and biological parameters of the handwashing wastewater. Treated water from the developed wastewater treatment system exhibited turbidity of 5 NTU, true color of 10 Pt-Co, apparent color of 6 Pt-Co, and TSS of 9 mgL-1, translating to removal efficiencies of up to 98.5%, 98.1%, 99.7%, and 96.9%, respectively. The residual total coliforms and E. coli of 1395 and 1180 CFU(100 mL)-1 respectively, were totally eliminated upon disinfection with 0.5 mL NaOCl (3.5% wt/ vol) per liter of treated wastewater. The treated water was thus suitable for recycling for handwashing purposes as opposed to letting handwashing wastewater merely go down the drain. This approach provides a resilient response to COVID-19, where communities faced with water scarcity can treat and recycle handwashing wastewater at the point of washing. It thus enables more people to have the opportunity to practice handwashing, abating the high risks of infection, which could otherwise arise.
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    Progress in deployment of biomass-based activated carbon in point-of-use filters for removal of emerging contaminants from water: A review
    (Elsevier, 2023-03-01) Menya, Emmanuel; Jjagwe, Joseph; Mpagi Kalibbala, Herbert; Storz, Henning; Wilberforce Olupot, Peter
    Emerging contaminants (ECs) are increasingly being detected in drinking water, posing numerous public health concerns. Granular activated carbon (GAC) offers good prospects for removing ECs at point-of-use (POU), enabling households to have access to safe water. This paper reviews the current advances in the deployment of biomass-derived GACs (B-GACs) for the removal of ECs at POU. It highlights key sources, pathways, and impacts of ECs on public health. It also reveals preparation routes and performance aspects of B-GACs for POU water purification. Knowledge gaps on the subject matter were identified. The review revealed that shells of nuts, which are typically hard and of high density are the most investigated for valorisation into GAC for POU water purification. To encourage the wide application of B-GACs for POU water purification, there is a need to tailor available soft, low-density biomass wastes and suit them as GAC precursors for the removal of ECs at the point of use. Future studies need to focus on tailoring the production of B-GACs for the removal of specific ECs from water. Additional future research insights include the identification of re-generation options for B-GACs, options for removal of residual nanoparticles from the filtrate, lifecycle analysis, and costing of various GAC-based POU water filters.
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    Synthesis and Application of Granular Activated Carbon from Biomass Waste Materials for Water Treatment :
    (Keai publishing, 2021-04-06) Jjagwe, Joseph; Olupot, Peter Wilberforce; Menya, Emmanuel; Mpagi Kalibbala, Herbert
    There is an increased global demand for activated carbon (AC) in the application of water treatment and purification. Water pollutants that have exhibited a greater removal efficiency by AC included but are not limited to heavy metals, pharmaceuticals, pesticides, natural organic matter, disinfection by-products, and microplastics. Granular activated carbon (GAC) is mostly used in aqueous solutions and adsorption columns for water treatment. Commercial AC is not only costly but also obtained from non-renewable sources. This has prompted the search for alternative renewable materials for AC production. Biomass wastes present a great potential for such materials because of their availability and carbonaceous nature. This, in turn, can reduce the adverse environmental effects caused by poor disposal of these wastes. The challenges associated with biomass waste-based GAC are their low strength and attrition resistance which make them easily disintegrate under the aqueous phase. This paper provides a comprehensive review of recent advances in the production of biomass waste-based GAC for water treatment and highlights future research directions. Production parameters such as granulation conditions, use of binders, carbonization, activation methods and their effect on textural properties are discussed. Factors influencing the adsorption capacities of the derived GACs, adsorption models, adsorption mechanisms, and their regeneration potentials are reviewed. The literature reveals that biomass waste materials can produce GAC for use in water treatment with the possibility of being regenerated. Nonetheless, there is a need to explore 1) the effect of preparation pathways on the adsorptive properties of biomass-derived GAC, 2) sustainable production of biomass-derived GAC based on life cycle assessment and techno-economic analysis, and 3) adsorption mechanisms of GAC for removal of contaminants of emerging concerns such as microplastics and unregulated disinfection by-products.