Enhancement of biogas production from domestic food waste by biofilm pretreatment method /
Food waste (FW) represents a significant portion of municipal solid waste (MSW). Appropriate managements of FW are required to minimize its environmental problems. Hence, food waste is known as a great resource for renewable energy especially for biogas which is a clean and renewable energy. Utiliza...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur :
Kulliyyah of Engineering, International Islamic University Malaysia,
2019
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| Subjects: | |
| Online Access: | http://studentrepo.iium.edu.my/handle/123456789/4762 |
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| Summary: | Food waste (FW) represents a significant portion of municipal solid waste (MSW). Appropriate managements of FW are required to minimize its environmental problems. Hence, food waste is known as a great resource for renewable energy especially for biogas which is a clean and renewable energy. Utilization of food as feedstock for biogas production currently represents a challenge due to an efficient hydrolysis, a pretreatment process and the first step of biogas conversion process (anaerobic digestion, AD). This limitation is due to solubilisation and degradation of the polymers contained in food waste. As a result, the production of biogas volume in methanogenesis step is affected. There is a necessity of enhancing biogas yield by increasing the biodegradation of organic compounds (OC) in hydrolysis step. Therefore, the present study focuses on the current knowledge available in the use of biofilm technologies for waste water treatment process and shows the opportunity of using biofilm in hydrolysis step of food waste to increase biogas. Thus, this study adopted the screened biofilm producer microorganisms to facilitate the biodegradation of OC and increase the volume of biogas production. As such, biofilm producing microorganism was first immobilized on granular activated carbon (GAC) surface and the optimum value of immobilization time, mass of GAC and size of microbial inoculum were found by using one-factor-at-a-time (OFAT) and response surface methodology (RSM) using face centered central composite design (FCCCD). Based on this result, 48 h of incubation, 8 g of GAC and 1 mL of inoculum were the optimum conditions when shaked at 37°C and 150 rpm. Different biofilm amounts (328 mg, 492 mg, 656 mg, 820 mg and 984 mg) were used in hydrolysis flask operated in a batch mode to increase the degradation of the OC. The optimal level of the hydrolysis degradation was at day 3 and 328 mg of biofilm where total solid (TS) decreased from 115 g/L to 79 g/L (31%) and TCOD decreased from 85330 mg/L to 54500 mg/L (36%). Development of anaerobic digestion of the hydrolyzed food waste operated in a semi-continuous mode has shown an increase of biogas volume to around 2000 ml/500 ml of feed for 50% of inoculum to feed ratio while 1523 mL, 753 mL, 502 mL of biogas for 30 %, 10 % of inoculum to feed ratio and the control, respectively which shows about 4-fold increased the biogas with biofilm pretreatment method. Thus, the analysis for TVS (volatile solid) reduction in the digester with 10%, 30%, 50% of inoculum and the control has increased to 30 %, 43.4 %, 45 % and 55 % respectively. TCOD removal has increased to 29 %, 33 %, 43 % and 56 % for the control, 10 %, 30 % and 50 % respectively for the inoculum to feed ratio. From these results, 50 % of inoculum to feed ratio has shown the highest biogas production and highest degradation of OC based on TVS reduction and TCOD reduction. Based on this study, biofilm pretreatment method can be considered promising method for the enhancement of biogas volume and the biodegradation of organic matter (OM). |
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| Physical Description: | xvii, 122 leaves : colour illustrations ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 104-117). |