Browsing by Author "Kansiime, Frank"

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    Assessment of nutrient retention by Natete wetland Kampala, Uganda
    (2010-12) Kanyiginya, V.; Kansiime, Frank; Kimwaga, Richard; Mashauri, Damas A.
    Natete wetland which is located in a suburb of Kampala city in Uganda is dominated by Cyperus papyrus and covers an area of approximately 1km2. The wetland receives wastewater and runoff from Natete town which do not have a wastewater treatment facility. The main objective of this study was to assess nutrient retention of Natete wetland and specifically to: determine the wastewater flow patterns in the wetland; estimate the nutrient loads into and out of the wetland; determine the nutrient retention by soil, plants and water column in the wetland; and assess the above and belowground biomass density of the dominant vegetation. Soil, water and plant samples were taken at 50m intervals along two transects cut through the wetland; soil and water samples were taken at 10cm just below the surface. Physico-chemical parameters namely pH, electrical conductivity and temperature were measured in situ. Water samples were analyzed in the laboratory for ammonium-nitrogen, nitrate-nitrogen, total nitrogen, orthophosphate and total phosphorus. Electrical conductivity ranged between 113μS/cm and 530μS/cm and the wastewater flow was concentrated on the eastern side of the wetland. pH varied between 6 and 7, temperature ranged from 19°C to 24°C. NH4-N, NO3-N, and TN concentrations were retained by 21%, 98%, and 35% respectively. Phosphorus concentration was higher at the outlet of the wetland possibly due to release from sediments and leaching. Nutrient loads were higher at the inlet (12,614±394kgN/day and 778±159kgP/day) than the outlet (2368±425kgN/day and 216±56kgP/day) indicating retention by the wetland. Plants stored most nutrients compared to soil and water. The belowground biomass of papyrus vegetation in the wetland was higher (1288.4±8.3gDW/m2) than the aboveground biomass (1019.7±13.8gDW/m2). Plant uptake is one of the important routes of nutrient retention in Natete wetland. It is recommended that harvesting papyrus can be an effective way of nutrient removal especially phosphorus which is not easily lost to the atmosphere like nitrogen. Natete wetland needs to be left in its natural state for better efficiency in nutrient retention. Bio-manipulation of the wetland by spreading the wastewater as it enters the wetland could enhance the interaction between plants and wastewater and subsequent nutrient removal.
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    Enhancement of Anaerobic Digestion of Nile Perch Fish Processing Wastewater
    (2009) Gumisiriza, Robert; Mshandete, Anthony M.; Rubindamayugi, Mugassa; Kansiime, Frank; Kivaisi, Amelia K.
    In East Africa, Nile perch processing into fish fillets for export generates large proportions of both solid and liquid fish wastes. These wastes are improperly utilized and/or disposed off untreated leading to environmental pollution problems. On the other hand, Nile perch fish processing wastewater (FPW) contains high concentrations of lipids and proteins, which have high methane yield potential. However, anaerobic digestion (AD) of FPW for methane production is limited due to process inhibition by lipids and ammonia intoxication. To overcome these limitations, the effects of co-digestion, physical and biological pretreatments on extent of methane yield were investigated. At a loading ratio of 1:1 (inoculum to substrate) with raw FPW, a methane yield of 0.56 m 3 /kgVS was obtained. Co-digestion of the residue with 10% gVS of brewery wastewater enhanced methane yield to a highest increment of 66%. Long chain fatty acids (LCFA) removal prior AD enhanced methane yield to an increment of 52% at LCFA removal of 8%. Pretreatment of FPW with aerobic microbial cultures isolated from a fish waste stabilization pond enhanced methane yield to an increment of 60% after 18 h, 68% after 15 h and 76.0% after 12 h of incubation, respectively, for strains CBR 11, BR 10 and a mixture of the two (CBR 11 + BR 10). The present study reports for the first time improvement of AD of Nile perch FPW by co-digestion, physical and biological pre-treatment methods and could be used as a basis for designing a pilot scale process.
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    Nile Perch Fish Processing Waste along Lake Victoria in East Africa: Auditing and Characterization
    (2009) Gumisiriza, Robert; Mshandete, Anthony M.; Rubindamayugi, Mugassa S. T.; Kansiime, Frank; Kivaisi, Amelia K.
    Worldwide, fish industry wastes are an important contaminant having an impact on the environment. The recovery of value added products from these residues constitutes an important waste reduction strategy for the industry. In East Africa, Nile perch fish processing into chilled fish fillet for export along Lake Victoria generate large proportions of both solid and liquid wastes. However, no thorough auditing and characterization of the waste has been done that would guide potential value addition through bioconversions and waste management. Auditing by surveying and mapping the fish processing industries was conducted along the lake. Waste quantification was done using specific guidelines for assessment of fish wastes. Analysis of the waste was carried out using standard methods. Annual solid waste and wastewater generation was estimated at 36,000 tonnes and 1,838,000 m3 , respectively. The wastewater generated was high strength with a total chemical oxygen demand of 12,400 mg/l and solid content of 5,580 mg/l. The wastewater contained 6,160 mg/l of lipids and 2,000 mg/l of protein. The Nutrient content was 20 mg/l of total phosphorous, 340 mg/l organic nitrogen and 61 mg/l of ammonia nitrogen. The current fish waste management systems in place were found to be neither efficient nor profitable, thus profitable options of fish waste utilization and waste reduction strategies are imperative. Modern and economically viable options of fish waste value addition, decision scheme and waste reduction strategies have been highlighted in this paper. In conclusion, large amounts of fish waste generated are a rich source of lipids and proteins, which could be utilized for production of value added products through bioconversions.