Browsing by Author "Nansubuga, Irene"

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    The Effect of Household Storage Tanks/ Vessels and User Practices on the Quality of Water: a systematic review of literature
    (Environmental Systems Research, 2021) Manga, Musa; Ngobi, Timothy G.; Okeny, Lawrence; Acheng, Pamela; Namakula, Hidaya; Kyaterekera, Elizabeth; Nansubuga, Irene; Kibwami, Nathan
    Household water storage remains a necessity in many communities worldwide, especially in the developing countries. Water storage often using tanks/vessels is envisaged to be a source of water contamination, along with related user practices. Several studies have investigated this phenomenon, albeit in isolation. This study aimed at developing a systematic review, focusing on the impacts of water storage tank/vessel features and user practices on water quality. Database searches for relevant peer-reviewed papers and grey literature were done. A systematic criterion was set for the selection of publications and after scrutinizing 1106 records, 24 were selected. These were further subjected to a quality appraisal, and data was extracted from them to complete the review.Microbiological and physicochemical parameters were the basis for measuring water quality in storage tanks or vessels. Water storage tank/vessel material and retention time had the highest effect on stored water quality along with age, colour, design, and location. Water storage tank/vessel cleaning and hygiene practices like tank/vessel covering were the user practices most investigated by researchers in the literature reviewed and they were seen to have an impact on stored water quality.There is evidence in the literature that storage tanks/vessels, and user practices affect water quality. Little is known about the optimal tank/vessel cleaning frequency to ensure safe drinking water quality. More research is required to conclusively determine the best matrix of tank/vessel features and user practices to ensure good water quality.
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    Effect of polyaluminium chloride water treatment sludge on effluent quality of domestic wastewater treatment
    (African Journal of Environmental Science and Technology, 2013) Nansubuga, Irene; Banadda, Noble; Babu, Mohammed; Verstraete, Willy; Wiele, Tom Van de
    Water resources degeneration is accelerated by the discharge of untreated wastewater and its byproducts, hence, reuse of these wastes is a major contributor to sustaining fresh water for the coming decades. In this study, the reuse of polyaluminium water treatment sludge (PA-WTS) as a flocculant aid to improve the effluent quality of wastewater during primary sedimentation is evaluated and presented. PA-WTS was collected from Gabba water treatment plant (Gabba WTP) Uganda, after the coagulation-flocculation process that makes use of aluminium chlorohydrate (ACH). The average aluminium residue concentration in PA-WTS was 3.4 mg/L. During this study, batch laboratory experiments were conducted in a jar-test apparatus in which different doses of PA-WTS were added. The results obtained showed a decrease in total suspended solids (TSS), chemical oxygen demand (COD), total ammonium nitrogen (TAN), and total phosphates (TP) in the supernatant after 30 min of settlement. The optimal PA-WTS dosage of 37.5 mL/L significantly (P<0.05) increased the TSS, TP and COD removal efficiencies by 15, 22 and 30%, respectively. It can be concluded that the PA-WTS positively complimented the sedimentation process in the primary treatment of wastewater to achieve better effluent quality.
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    Enhancement of biogas potential of primary sludge by co-digestion with cow manure and brewery sludge
    (International Journal of Agricultural and Biological Engineering, 2015) Nansubuga, Irene; Banadda, Noble; Babu, Mohammed; Vrieze, Jo De; Verstraete, Willy; Rabaey, Korneel
    Anaerobic digestion (AD) has long been used to treat different types of organic wastes especially in the developed world. However, organic wastes are still more often considered as a waste instead of a resource in the developing world, which contributes to environmental pollution arising from their disposal. This study has been conducted at Bugolobi Sewage Treatment Plant (BSTP), where two organic wastes, cow manure and brewery sludge were co-digested with primary sludge in different proportions. This study was done in lab-scale reactors at mesophilic temperature and sludge retention time of 20 d. The main objective was to evaluate the biodegradability of primary sludge generated at BSTP, Kampala, Uganda and enhance its ability of biogas production. When the brewery sludge was added to primary STP sludge at all proportions, the biogas production rate increased by a factor of 3. This was significantly (p < 0.001) higher than observed gas yield (337±18 mL/(L•d)) in the control treatment containing (only STP sludge). Co-digesting STP sludge with cow manure did not show different results compared to the control treatment. In conclusion, Bugolobi STP sludge is poorly anaerobically degradable with low biogas production but co-digestion with brewery sludge enhanced the biogas production rate, while co-digestion with cow manure was not beneficial.