Browsing by Author "Mbabazi, Jolocam"

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    Nitrification in modified sewerage stabilisation ponds prior to discharge into the Ugandan side of Lake Victoria
    (International Journal of Environmental Studies., 2010-12-08) Mbabazi, Jolocam; Wanasolo, W.; Gava, J.; Kwetegyeka, J.
    Large volumes of wastewater in the Ugandan capital Kampala have seriously polluted Lake Victoria, from which the city draws its freshwater. Untreated effluent drains directly into this lake. In tropical temperatures, oxidation ponds are used for wastewater treatment, especially for organic matter. This technology should be the focus of work to improve its efficacy, and thus to secure the sustainability of the lake and its freshwater fish which are marketed worldwide. A pilot scale plant was set up comprising an anaerobic tank, a facultative pond and four fibre‐glass maturation tanks. The total nitrification rates in the tanks T1–T4 were 5.5, 7.5, 10.1 and 6.4 (±0.4) mg‐N/l/day, respectively. For more efficient wastewater treatment stabilisation pond systems, a modification similar to that in T3 should be considered. T3 was constructed with biofilm attachment surfaces in a manner which allowed effluent to be channelled round them, contrary to direct T1 flow which is currently in use.
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    Speciation of heavy metals in water from the Uganda side of Lake Victoria
    (International Journal of Environmental Studies., 2010-02-15) Mbabazi, Jolocam; Twinomuhwezi, H.; Wasswa, J.; Ntale, M.; Mulongo, G.; Kwetegyeka, J.; SchrǾder, K.H.
    Different forms of copper Cu, zinc Zn, lead Pb and cadmium Cd in water from the Uganda side of Lake Victoria (25°C, pH 6.75–7.18), the second largest inland freshwater lake in the world, have been studied using ion‐exchange, dialysis and atomic absorption spectrophotometry. The results indicate that heavy metals Cu, Zn, Pb and Cd are present mainly in the cationic form (80–83%). Small quantities of anionic (13–22%), non‐ionic, dialyzable (4–8%), and non‐ionic, non‐dialyzable (< 1.3–4.4%) forms were also detected for all metals except Cd. The corresponding concentrations lay in the ranges: cationic, 0.06–0.99; anionic, < 0.001–0.25; non‐ionic, dialyzable, < 0.001–0.08; non‐ionic, non‐dialyzable, < 0.001–0.06 µg ml−1. The existence of the metals in non‐ionic and non‐dialyzable forms is attributable to metal associations with high relative molecular mass (RMM) organic matters.