Research Repository :: Browsing by Author "Rubindamayugi, Mugassa S. T."

Browsing by Author "Rubindamayugi, Mugassa S. T."

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Anaerobic Batch Co-Digestion of Sisal Pulp and Fish Wastes
(Elsevier, 2004) Mshandete, Anthony M.; k, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
Co-digestion of various wastes has been shown to improve the digestibility of the materials and biogas yield. Batchwise digestion of sisal pulp and fish waste was studied both with the wastes separately and with mixtures in various proportions. While the highest methane yields from sisal pulp and fish waste alone were 0.32 and 0.39 m3 CH4/kg volatile solids (VS), respectively, at total solid (TS) of 5%, co-digestion with 33% of fish waste and 67% of sisal pulp representing 16.6% of TS gave a methane yield of 0.62 m3 CH4/kg VS added. This is an increase of 59–94% in the methane yield as compared to that obtained from the digestion of pure fractions at 5% TS.
Biosafety Education Relevant to Genetically Engineered Crops for Academic and Non-Academic Stakeholders in East Africa
(2009) Sengooba, Theresa; Grumet, Rebecca; Hancock, James F.; Zawedde, Barbara; Kitandu, Lazaro; Weebadde, Cholani; Karembu, Margaret; Kenya, E.; Meredia, K.; Nampala, P.; Ochanda, J. O.; Quemada, Hector; Rubindamayugi, Mugassa S. T.
Development and deployment of genetically engineered crops requires effective environmental and food safety assessment capacity. In-country expertise is needed to make locally appropriate decisions. In April 2007, biosafety and biotechnology scientists, regulators, educators, and communicators from Kenya, Tanzania, and Uganda, met to examine the status and needs of biosafety training and educational programs in East Africa. Workshop participants emphasized the importance of developing biosafety capacity within their countries and regionally. Key recommendations included identification of key biosafety curricular components for university students; collaboration among institutions and countries; development of informational materials for non-academic stakeholders and media; and organization of study tours for decision makers. It was emphasized that biosafety knowledge is important for all aspects of environmental health, food safety, and human and animal hygiene. Thus, development of biosafety expertise, policies and procedures can be a stepping stone to facilitate improved biosafety for all aspects of society and the environment.
Decolorization of Synthetic and Real Textile Wastewater by the Use of White-Rot Fungi
(2006) Nilsson, I.; Möller, A.; Mattiasson, Bo; Rubindamayugi, Mugassa S. T.; Welander, Ulrika
Batch and continuous reactors inoculated with white-rot fungi were operated in order to study decolorization of textile dyes. Synthetic wastewater containing either Reactive Blue 4 (a blue anthraquinone dye) or Reactive Red 2 (a red azo dye) was used during the first part of the study while real wastewater from a textile industry in Tanzania was used in the later part. Trametes versicolor was shown to decolorize both Reactive Blue 4 and Reactive Red 2 if glucose was added as a carbon source. Reactive Blue 4 was also decolorized when the fungus was allowed to grow on birch wood discs in a continuous biological rotating contactor reactor. The absorbance at 595 nm, the wavelength at which the dye absorbs at a maximum, decreased by 70% during treatment. The initial dye concentration in the medium was 200 mg/l and the hydraulic retention time in the reactor 3 days. No glucose was added in this experiment. Changes of the absorbance in the UV range indicated that the aromatic structures of the dyes were altered. Real textile wastewater was decolorized by Pleurotus flabellatus growing on luffa sponge packed in a continuous reactor. The reactor was operated at a hydraulic retention time of 25 h. The absorbance at 584 nm, the wavelength at which the wastewater absorbed the most, decreased from 0.3 in the inlet to approximately 0.1 in the effluent from the reactor.
Effect of Aerobic Pre-Treatment on Production of Hydrolases and Volatile Fatty Acids during Anaerobic Digestion of Solid Sisal Leaf Decortications Residues
(2008) Mshandete, Anthony M.; Björnsson, Lovisa; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
The effect of aerobic pretreatment on the production of hydrolases and volatile fatty acids during anaerobic digestion of solid sisal decortications leaf residue (SLDR) was investigated. Batch solid waste bioreactors with working volume of 2 litres were used in this study. Batch loads of aerobically treated or untreated sisal leaf residue inoculated with activated sludge mixed culture were packed into the bioreactors and operated anaerobically for 400 h. The fermentation products were mainly (mg/g total volatile fatty acids, VFAs): acetic acid (287), n-butyric acid (201), n-valeric acid (96) and caproic acid (62) as well as with low amounts of propionic acid and iso-butyric acid for aerobic pre-treated sisal leaf waste solids. Contrarily, for the untreated system, the fermentation products were chiefly (mg/g total volatile fatty acids): propionic acid (317), iso-butyric acid (276), n-butyric acid (96), acetic acid (84) and insignificant amounts of n-valeric acid, iso-valeric acid and caproic acid. Although the activities of hydrolytic enzymes found were similar for both treated and untreated SLDR, proportions of VFAs obtained with the former residues appeared to be better substrates for biomethanantion than those obtained from the latter substrates. These results indicated the potential of aerobic pre-treatment for enhanced bioconversion of SLDR. The present study, reports for the first time the types and levels of VFAs and hydrolases produced during anaerobic digestion of aerobic pre-treated SLDR and could be used as a basis for designing a pilot scale process.
Effect of Particle Size on Biogas Yield from Sisal Fibre Waste
(2006) Mshandete, Anthony M.; Björnsson, Lovisa; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
The degradation and biogas production potential of sisal fibre waste could be significantly increased by pre-treatment for reduction of particle size. Batch-wise anaerobic digestion of sisal fibre waste was carried out in 1-l digesters with fibre sizes ranging from 2 to 100 mm, at an ambient temperature of 33 °C. Sediment from a stabilisation pond at a sisal production plant was used as starter seed. Total fibre degradation increased from 31% to 70% for the 2 mm fibres, compared to untreated sisal fibres. Furthermore, the results confirmed that methane yield was inversely proportional to particle size. Methane yield increased by 23% when the fibres were cut to 2 mm size and was 0.22 m3 CH4/kg volatile solids, compared to 0.18 m3 CH4/kg volatile solids for untreated fibres. By anaerobic digestion and biogas production, the 148,000 tonne of waste sisal fibres generated annually in Tanzania could yield 22 million m3 of methane, and an additional 5 million m3 of methane if pre-treatment by size reduction to 2 mm was applied.
Enhancement of Anaerobic Batch Digestion of Sisal Pulp Waste by Mesophilic Aerobic Pre-Treatment
(Taylor and Francis, 2004) Mshandete, Anthony M.; Murto, Marika; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
The performance of anaerobic, packed-bed bioreactors treating leachate from potato waste was evaluated in terms of organic loading rate (OLR) as well as the recirculation flow rate. Two 1 litre bioreactors, filled with porous glass beads as biofilm carriers and with continuous recirculation flow rates of 10 ml min-1 and 20 ml min-1 respectively, were used in the experiment. The OLR applied to each bioreactor was increased stepwise from 4 to 12 kg chemical oxygen demand (COD) m-3d-1 by increasing feed flow rate. The methane yields decreased with increasing OLR in both bioreactors. The methane yield for the bioreactor with the lower recirculation flow rate ranged between 0.10 and 0.14 m3 CH4 kg COD-1 removed, while for the other bioreactor it was 0.14–0.20 m3 CH4 kg COD-1 removed. Both bioreactors demonstrated stable COD removal which was around 95% for the bioreactor with lower flow of recirculation while for the other it was 92%, over a range of OLRs of 4–8 kg COD m-3d-1. The bioreactor with the lower recirculation flow rate showed operational stability when a high OLR, namely 12 kg COD m-3d-1, was applied, while the other one became overloaded. There was an accumulation of volatile fatty acids which gave a corresponding drop in pH because the system had a low buffering capacity and this thus ultimately led to process failure. This study demonstrated the suitability of a packed bed bioreactor operated at lower recirculation flow rate for treating leachate from potato waste
Food Biotechnology and Education
(2009) Sengooba, Theresa; Grumet, Rebecca; Hancock, James F.; Zawedde, Barbara; Kitandu, Lazaro; Weebadde, Cholani; Karembu, Margaret; Kenya, Eucharia; Meredia, Karim; Nampala, Paul; Ochanda, James O.; Quemada, Hector; Rubindamayugi, Mugassa S. T.
Development and deployment of genetically engineered crops requires effective environmental and food safety assessment capacity. In-country expertise is needed to make locally appropriate decisions. In April 2007, biosafety and biotechnology scientists, regulators, educators, and communicators from Kenya, Tanzania, and Uganda, met to examine the status and needs of biosafety training and educational programs in East Africa. Workshop participants emphasized the importance of developing biosafety capacity within their countries and regionally. Key recommendations included identification of key biosafety curricular components for university students; collaboration among institutions and countries; development of informational materials for non-academic stakeholders and media; and organization of study tours for decision makers. It was emphasized that biosafety knowledge is important for all aspects of environmental health, food safety, and human and animal hygiene. Thus, development of biosafety expertise, policies and procedures can be a stepping stone to facilitate improved biosafety for all aspects of society and the environment.
Influence of Recirculation Flow Rate on the Performance of Anaerobic Packed-bed Bioreactors Treating Potato-Waste Leachate
(Taylor & Francis, 2010-03-11) Mshandete, Anthony M.; Murto, M.; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, B.
The performance of anaerobic, packed-bed bioreactors treating leachate from potato waste was evaluated in terms of organic loading rate (OLR) as well as the recirculation flow rate. Two 1 litre bioreactors, filled with porous glass beads as biofilm carriers and with continuous recirculation flow rates of 10 ml min-1 and 20 ml min-1 respectively, were used in the experiment. The OLR applied to each bioreactor was increased stepwise from 4 to 12 kg chemical oxygen demand (COD) m-3d-1 by increasing feed flow rate. The methane yields decreased with increasing OLR in both bioreactors. The methane yield for the bioreactor with the lower recirculation flow rate ranged between 0.10 and 0.14 m3 CH4 kg COD-1 removed, while for the other bioreactor it was 0.14–0.20 m3 CH4 kg COD-1 removed. Both bioreactors demonstrated stable COD removal which was around 95% for the bioreactor with lower flow of recirculation while for the other it was 92%, over a range of OLRs of 4–8 kg COD m-3d-1. The bioreactor with the lower recirculation flow rate showed operational stability when a high OLR, namely 12 kg COD m-3d-1, was applied, while the other one became overloaded. There was an accumulation of volatile fatty acids which gave a corresponding drop in pH because the system had a low buffering capacity and this thus ultimately led to process failure. This study demonstrated the suitability of a packed bed bioreactor operated at lower recirculation flow rate for treating leachate from potato waste.
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.
Performance of a Small Wastewater Stabilisation Pond System in Tropical Climate in Dar Es Salaam, Tanzania
(2004) Mbwele, Lydia A.; Rubindamayugi, Mugassa S. T.; Kivaisi, Amelia K.; Dalhammar, Gunnel
Waste stabilisation ponds (WSP) are widely used in Tanzania. Their traditional design focuses on BOD and pathogen removal, but nutrient removal is equally important. WSP performance was evaluated to come up with information that would be used to evaluate pond performance. Samples were analysed twice a month for six months. Results showed total and faecal coliform removal by 4 log units (99.96 and 99.98% respectively). There was partial reduction of COD, BOD, (46% and 27% respectively), conductivity and total dissolved solids (32.6 and 32.4% respectively). Variation for the nutrients like inorganic phosphorus, ammonia nitrogen, nitrite nitrogen, and nitrate nitrogen was not consistent and there was practically no reduction, although there is some nitrification taking place. From this study it may be concluded that BOD and nutrients may not be useful to evaluate pond performance. Instead parameters such as conductivity, total dissolved solids, coliform bacteria, dissolved oxygen, pH and chlorophyll would be suitable for that purpose, due to their consistent variation within cells of the pond system. But BOD and nutrient removal are important and have to be improved to enhance treatment in the WSP.
Performance of Biofilm Carriers in Anaerobic Digestion of Sisal Leaf Waste Leachate
(2008) Mshandete, Anthony M.; Björnsson, Lovisa; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
Three methanogenic biofilm bioreactors were studied to evaluate the performance of three types of carriers. The carrier material were consisted of sisal fibre waste, pumice stone and porous glass beads, and the bioprocess evaluated was the methanogenesis anaerobic digestion of sisal leaf waste leachate. Process performance was investigated by increasing the organic loading rate (OLR) step-wise. The best results were obtained from the bioreactor packed with sisal fibre waste. It had the highest chemical oxygen demand (COD) removal efficiencies in the range of 80-93% at OLRs in the range of 2.4-25 g COD L-1d-1. The degradation pattern of volatile fatty acids (VFAs) showed that the degradation of propionate was limiting at higher OLRs. The stable pH and higher partial alkalinity (PA) of the outflow illustrated that packed-bed bioreactors have a good ability to withstand the variations in load and volatile fatty acid concentrations that can occur in a two-stage anaerobic process. In conclusion, sisal fibre waste was shown to be a novel promising biofilm carrier and would work very well in methanogenic biofilm bioreactors treating sisal leaf tissue waste leachate. Furthermore both sisal wastes are available in the neighbourhood of sisal industries, which makes anaerobic digestion scale up at sisal factory level feasible and cost-effective.
Two-Stage Anaerobic Digestion of Aerobic Pre-Treated Sisal Leaf Decortications Residues: Hydrolases Activities and Biogas Production Profile
(2008) Mshandete, Amelia K.; Björnsson, Lovisa; Kivaisi, Amelia K.; Rubindamayugi, Mugassa S. T.; Mattiasson, Bo
A two-stage system was investigated for anaerobic digestion (AD) of aerobically pre-treated sisal leaf decortication residue (SLDR) with regard to hydrolytic enzymes and biogas production. The system consisted of a solid-bed bioreactor for hydrolysis connected to methanogenic bioreactor packed with sisal fibre decortication residues (SFDR) as biofilm carriers. Some of the enzymes produced by microorganisms to hydrolyse SLDR were found to be pectinase, filter paper cellulase, amylase, - glucosidase, carboxylmethyl cellulase, xylanase and protease. Enzyme activities observed in the acidogenic bioreactor were much higher than those in the methanogenic bioreactor. The hydrolysis and the methanogenic stages were well separated, as indicated by the high carbon dioxide production, high volatile fatty acids (VFAs) concentration and low pH in the acidogenic bioreactor compared with high methane production, low VFAs concentration and above neutral pH in the effluent of the methanogenic bioreactor. Digestion of SLDR gave energy yields of 2.45 kWh/kg volatile solids added in the form of methane. The integrity of the methane filter was maintained throughout the period of operation producing biogas with 51 - 70% methane content. A stable effluent pH showed that the methanogenic bioreactor had good ability to withstand the variations in load and VFAs concentrations that occurred in the two-stage process. In conclusion, the results of this study showed that the two-stage system was suitable for effective stabilization and biomethanation of SLDR.

Browsing by Author "Rubindamayugi, Mugassa S. T."

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