Browsing by Author "Wabwire, Andrew"

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    Development and appraisal of handwash-wastewater treatment system for water recycling as a resilient response to COVID-19
    (Journal of Environmental Chemical Engineering, 2021) Olupot, Peter W.; Menya, Emmanuel; Jjagwe, Joseph; Wakatuntu, Joel; Kavuma, Tonny; Wabwire, Andrew; Kavuma, Steven; Okodi, Samuel M.; 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 a 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 purpose 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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    "Experience from Rural Electrification in Uganda: A Case Study of a Husk Powered System in Tiribogo Village''
    (In 9th Sida Reg. Conf, 2014) Okure, Mackay A. E.; Musinguzi, Wilson; Wabwire, Andrew; Bagenda, Ssengonzi
    To address the need for electricity in some rural communities in Uganda with seasonal agricultural waste or biomass, we need a biomass to electricity conversion system. A low-cost biomass to electric energy conversion husk powered system was imported from the Husk Power Systems of India. The system was installed in 2012 in Tiribogo Village, Muduma Parish in Mpigi District supplying 32kWe power to an isolated power grid. The system has operated since October 2012 with a daily usage of 7 hours. The biomass flow rate of 30 kg/hr for maize cobs and 25 kg/hr for coffee husks. The power output measured was 34 kW with line voltage of 244 V/ 50 Hz and phase voltage 422 V with a power factor of 0.85 at the generation side. The specific fuel consumption was 0.88 kg/kWh for maize cobs and 0.74 kg/kWh for coffee husks. The system electrical efficiency was 20.5% for maize cobs and 30.2% for coffee husk. The solid waste products generated were 12% for maize cobs and 10% for coffee husks of the total biomass fuel put into the gasifier. A software business model was generated using RETScreen software, considering the total cost of inputs and cost sales, the unit cost of power was found to be US$ 0.259 (UGX 686/=). The business simple payback was 3.3 years for maize cobs and 3.4 years for coffee husks. The break even period for the business was found to be 6.2 years for maize cobs and 6.3 years for coffee husks respectively if all power generated is sold. The fact that maize cobs were offered free from the community with transport cost of USD 15 per ton and coffee husk were bought at a rate of USD 40 inclusive transport per ton caused the difference in the financial parameters. In conclusion the operation of a 32 kWe power plant was found satisfactory using the local biomass and it produced more power than the community could consume or buy at that time therefore it is recommended for the rural communities generating 7 tons of annually.