Browsing by Author "Gumisiriza, Robert"

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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.