Browsing by Author "Kassuwi, Shaaban A. A."

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    Anaerobic Co-Digestion of Biological Pre-Treated Nile Perch Fish Solid Waste with Vegetable Fraction of Market Solid Waste
    (Asian Research Publishing Network (ARPN), 2012) Kassuwi, Shaaban A. A.; Mshandete, Anthony M.; Kivaisi, Amelia K.
    Anaerobic co-digestion of various organic wastes has been shown to improve biogas yield of fish wastes. This paper presents the effect of pre-treating Nile perch fish solid waste (FSW) using CBR-11 bacterial culture (CBR-11-FSW) and commercial lipase enzyme (Lipo-FSW), followed by batch anaerobic co-digestion with vegetable fractions of market solid waste (VFMSW) in various proportions, using potato waste (PW) and cabbage waste (CW) as co-substrates either singly or combined. Results indicated that CBR-11 pre-treated FSW co-digested with PW or CW in 1:1 ratio (substrate: inoculum) had positive effect on methane yield, while Lipo pre-treated FSW had negative effect on methane yield. Using CBR-11-FSW:PW the highest yield was 1.58 times more than the untreated FSW. Whereas, using Lipo-FSW:CW the highest yield was 1.65 times lower than un-treated FSW. Furthermore, the optimal mixture of CBR-11 pre-treated FSW and PW and CW co-substrates resulted into higher methane yield of 1, 322 CH4 ml/gVS using CBR-11-FSW (10):PW (45):CW (45) ratio. The ratio enhanced methane yield to 135% compared to control. In conclusion, results demonstrates that optimal mixture of CBR-11 pre-treated FSW with both PW and CW as co-substrates enhanced methane yield and provide base line data for potential application in continuous anaerobic bioreactors investigation.
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    Combined Thermo-Microbial Pre-Treatments Methods for Enhanced Biogas Production from Nile Perch Fish Solid Waste in Tanzania
    (2012) Kassuwi, Shaaban A. A.; Mshandete, Anthony M.; Kivaisi, Amelia K.
    Anaerobic digestion (AD) of fish waste is difficult mainly due to high protein and lipid content which inhibit the process. Pre-treatments methods are option to improved AD of fish wastes for biogas production. Effects of heating, pasteurization separately and combined with CBR-11 bacteria strain culture (internal code) pre-treatment on biogas production from fish solid waste (FSW) was investigated in batch anaerobic bioreactors (BAB). The two thermo pre-treatment methods had a positive effect with best results 311 and 361 CH 4 ml/g volatile solids (VS) added obtained from heated FSW for 90 seconds at 130 o C and pasteurised FSW for 60 minutes at 70 o C, respectively. The highest methane yield were two fold compared with non-pre-treated FSW (163 CH 4 ml/gVS added). Heated and pasteurised FSW each separately combined with CBR 11 bacterial culture pre-treatment prior to AD had a maximum methane yield of 697 and 491 CH 4 ml/gVS added , respectively. Resulting in three to four fold increases in methane yield compared with non-pre-treated FSW (163 CH 4 ml/gVS added). The methane content of the biogas ranged between 70-81% regardless of pre-treatment methods employed. In conclusion combined thermo-microbial pre-treatment is a novel method for enhanced biogas production of FSW. However, remain to be tested in continuous anaerobic digester with or without co-digestion.
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    Nile Perch Fish Scales a Novel Biofilm Carrier in the Anaerobic Digestion of Biological Pre-Treated Nile Perch Fish Solid Waste
    (2013) Kassuwi, Shaaban A. A.; Mshandete, Anthony M.; Kivaisi, Amelia K.
    Improved stability and anaerobic digestion (AD) process in a packed bed bioreactor can be achieved if bacterial consortia are retained in the process through the use of biofilms carriers. Three methanogenic biofilms carriers for biomass retention were studied to evaluate the performance of methanogenesis AD of Nile Perch fish solid wastes pre-treated by bacterial culture coded (CBR-11). The carrier material evaluated consisted of sisal fibre waste, pumice stones and Nile perch fish scales. Process performance was investigated by increasing the organic loading rate (OLR) step-wise. The best results were obtained from the bioreactor packed with Nile perch fish scales. It had the lowest total volatile fat acids (TVFA) accumulated at OLR in the range of 1-12 g volatile solids (VS)/l/d. The degradation pattern showed that the TVFAs was limiting at higher OLRs. The pH profiles showed an increasing pattern with an increase in OLRs. The pH was low (8-8.3) at low OLRs (1-6) gVS/l/d and increased to a higher level (8.3-8.7) at higher OLR (9-12) gVS/l/d. Despite the high pH level reached, the bioreactor packed with fish scales had a good ability to withstand the changes in load and VFA concentrations shocks that can occur in packed bed anaerobic bioreactors. In conclusion Nile perch fish scales was demonstrated to be potential novel biofilms carrier that would work well in methanogenic biofilms bioreactors treating fish solid waste. Moreover, Nile perch solid fish wastes and fish scales are available within the vicinity, which could make AD scale-up at fish processing industry feasible and cost effective