Research Repository :: Browsing by Author "Mattiasson, Bo"

Browsing by Author "Mattiasson, Bo"

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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.
Characterisation and Evaluation of a Novel Feedstock, Manihot Glaziovii, Muell. Arg, for Production of Bioenergy Carriers: Bioethanol and Biogas
(2014) Moshi, Anselm P.; Crespo, Carla F.; Badshah, Malik; Hosea, Ken M. M.; Mshandete, Anthony M.; Elisante, Emrode; Mattiasson, Bo
The objective of this study was to characterise and evaluate a wild inedible cassava species, Manihot glaziovii as feedstock for bioenergy production. Tubers obtained from 3 different areas in Tanzania were characterised and evaluated for bioethanol and biogas production. These bioenergy carriers were produced both separately and sequentially and their energy values evaluated based on these two approaches. Composition analysis demonstrated that M. glaziovii is a suitable feedstock for both bioethanol and biogas production. Starch content ranged from 77% to 81%, structural carbohydrates 3–16%, total crude protein ranged from 2% to 8%. Yeast fermentation achieved ethanol concentration of up to 85 g/L at a fermentation efficiency of 89%. The fuel energy of the bioethanol and methane from flour-peels mix ranged from 5 to 13 and 11 to 14 MJ/kg VS, respectively. Co-production of bioethanol and biogas in which the peels were added to the fermentation residue prior to anaerobic digestion produced maximum fuel energy yield of (15–23 MJ/kg VS).
Combined Production of Bioethanol and Biogas from Peels of Wild Cassava Manihot Glaziovii
(Elsevier, 2015) Moshi, Anselm P.; Temu, Stella G.; Ngesa, Ivo A.; Malmo, Gashaw; Hosea, Ken M.; Elisante, Emrode; Mattiasson, Bo
Cassava peels were pre-treated with alkali, enzyme and in sequential combination of alkali and enzyme, and used for production of bioethanol or biogas, or both (in sequence, bioethanol followed by biogas). The Biogas Endeavour and Automatic Methane Potential Test Systems were used for production of bioethanol and biogas, respectively. The bioethanol yield and volumetric productivity achieved with alkali pre-treatment combined in sequence with enzyme pre-treatment were 1.9 mol/mol and 1.3 g/L/h which was higher than the yield (1.6 mol/mol) and volumetric productivity (0.5 g/L/h) obtained from only enzyme pre-treated peels. Alkali combined in sequence with enzyme was proven to be the best treatment showing a 56% improvement in methane yield compared to the yield from untreated sample. Combined ethanol and methane production resulted in 1.2–1.3-fold fuel energy yield compared to only methane and 3–4-fold compared to only ethanol production. This study therefore provides practical data on the scenario best suited for the harnessing of energy from cassava peels.
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
High Bioethanol Titre from Manihot Glaziovii through Fed-Batch Simultaneous Saccharification and Fermentation in Automatic Gas Potential Test System
(Elsevier, 2014) Moshi, Anselm P.; Crespo, Carla F.; Badshah, Malik; Hosea, Ken M.; Mshandete, Anthony M.; Mattiasson, Bo
A process for the production of high bioethanol titre was established through fed-batch and simultaneous saccharification and fermentation (FB-SSF) of wild, non-edible cassava Manihot glaziovii. FB-SSF allowed fermentation of up to 390 g/L of starch-derived glucose achieving high bioethanol concentration of up to 190 g/L (24% v/v) with yields of around 94% of the theoretical value. The wild cassava M. glaziovii starch is hydrolysable with a low dosage of amylolytic enzymes (0.1–0.15% v/w, Termamyl® and AMG®). The Automatic Gas Potential Test System (AMPTS) was adapted to yeast ethanol fermentation and demonstrated to be an accurate, reliable and flexible device for studying the kinetics of yeast in SSF and FB-SSF. The bioethanol derived stoichiometrically from the CO2 registered in the AMPTS software correlated positively with samples analysed by HPLC (R2 = 0.99).
High Temperature Simultaneous Saccharification and Fermentation of Starch from Inedible Wild Cassava (Manihot Glaziovii) to Bioethanol Using Caloramator Boliviensis
(Elsevier, 2015) Moshi, Anselm P.; Hosea, Ken M.; Elisante, Emrode; Mamo, G.; Mattiasson, Bo
The thermoanaerobe, Caloramator boliviensis was used to ferment starch hydrolysate from inedible wild cassava to ethanol at 60 °C. A raw starch degrading α-amylase was used to hydrolyse the cassava starch. During fermentation, the organism released CO2 and H2 gases, and Gas Endeavour System was successfully used for monitoring and recording formation of these gaseous products. The bioethanol produced in stoichiometric amounts to CO2 was registered online in Gas Endeavour software and correlated strongly (R2 = 0.99) with values measured by HPLC. The organism was sensitive to cyanide that exists in cassava flour. However, after acclimatisation, it was able to grow and ferment cassava starch hydrolysate containing up to 0.2 ppm cyanide. The reactor hydrogen partial pressure had influence on the bioethanol production. In fed-batch fermentation by maintaining the hydrogen partial pressure around 590 Pa, the organism was able to ferment up to 76 g/L glucose and produced 33 g/L ethanol.
Mixed Palm Oil Waste Utilization through Integrated Mushroom and Biogas Production
(2016) Temu, Stella; Moshi, Anselm P.; Nges, Ivo A.; Mshandete, Anthony M.; Kivaisi, Amelia K.; Mattiasson, Bo
Aim of the Study: The study was to integrate mushroom and biogas production using mixed palm oil to provide both food and energy source to palm oil producing communities as well as reducing environmental pollution. Design of the Study: Mixed palm oil waste was divided into two portions. One portion was used for mushroom cultivation and afterwards the spent mushroom substrate and the untreated portion were used for biogas production. Methodology: Structural sugars analysis was performed using double acid hydrolysis technique. Total crude protein was determined through kjeldal acid digestion method. Lipids were extracted using a mixture of chloroform and methanol and quantified gravimetrically. The mushroom strain (Coprinus scinereus) was cultivated on the mixed palm oil waste. Afterwards, the spent mushroom substrate and the untreated palm oil waste were subjected to anaerobic digestion in automatic methane potential test system. Place and Duration of Study: The study was completed in 2 years from 2014-2015. Mushroom cultivation was carried out at the University of Dar-e salaam, Tanzania, whereas feedstock characterization and anaerobic digestion were performed at Lund University, Sweden. Results: Compositional analysis disclosed that the feedstock contains (% w/w) 0.1 proteins, 3.3 carbohydrates, 22.5 lipids, and 73 lignin. Mushroom yield was 0.64 g /g of substrate at a biological efficiency of 71.4 g/100 g of substrate and productivity of 21.5±0.5%. Consequently total carbohydrates and lipids were decreased by 70% and 76% while the relative content of lignin and protein increased by 23% and 50%, respectively. Particle size reduction (<4 mm) resulted to increased methane yield by 66%. The untreated and biologically treated mixed palm oil wastes yielded 517 and 287 of CH4 L/Kg VS added which corresponded to 80% and 64.5% of theoretical methane yield, respectively. Conclusion: Combined mushroom and biogas production offer superior benefits in the utilization of the palm oil waste.
Performance of a Sisal Fibre Fixed-Bed Anaerobic Digester for Biogas Production from Sisal Pulp Waste
(2009) Mshandete, Anthony M.; Björnsson, Lovisa; Kivaisi, Amelia K.; Rubindamayugi, M. S. T; Mattiasson, Bo
A single stage anaerobic digester employing a sisal fibre waste fixed bed was studied for biogas production from sisal pulp waste. The fibre was colonized by microorganisms involved in biogas production. The sisal pulp waste to be digested was fed from the top and was sprinkled intermittently with recirculating leachate from the material. Organic loading rates of 0.1-10 kg volatile solids (VS) m-3 d-1 could be applied and methane yields in the range of 0.13-0.48 m3 CH4 kg -1 VS added were obtained. The average methane content in the biogas produced from sisal pulp waste was 55%, and the biogas production rate was 0.15-0.54 m3 m-3 d-1 . The methane yield obtained and the highest organic loading rate that could be sustained by this simple, fixed-bed digester are indications of an attractive system in terms of performance and reliability. It is concluded that the sisal fibre waste fixed bed is a promising carrier for microbes and can be employed for long-term operation without changing the bed.
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 "Mattiasson, Bo"

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