An Approach to Enhance Biomethanation by Thermophilic Aerobic Digestion of Combined Vegetable Waste
| Autor: | M.G. Takwale, V.S. Ghole, Ashwini J. Kamble |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | IOSR Journal of Environmental Science, Toxicology and Food Technology. 8:01-07 |
| ISSN: | 2319-2402 2319-2399 |
| DOI: | 10.9790/2402-08120107 |
| Popis: | In biogas volatile fatty acid are the principle source of energy for methanogens and an increase in their concentration can enhance the process performance of biogas digester. A two phase anaerobic digestion system was used to study the effect of various factors on the net production of volatile fatty acid (VFA). For this purpose thermophilic digester maintained at 55°c (i.e. digester I) and the main digester was kept at ambient temperature (i.e. digester II). Co-digestion of vegetable waste and cow dung was investigated in two phase anaerobic biodigester system. A comparative study was carried out between control and experimental system. The amendment was controlled air supply in predigester (digester I) designed to supply with precise control in the experimental system and no aeration was done in the predigester of control system. The conditions of start up and operation were same in both the systems except controlled supply of air. A conversion of an average of 75% of organic solids fed into digester at total of 15 days hydraulic retention time (HRT) was obtained for both the system. The organic loading rate in phase I digester was 4-4.5 kg VS/m 3 /d. This phase effluent portray a drop in the pH to 4.4-4.7 as high volatile fatty acid produced in the range of 2380-5464 mg/lt with a corresponding gas production of 0.401 m 3 /kg vs. fed in the experimental system, which showed increased biogas yield than the control system. Due to the auto thermal thermophilic aerobic digestion the VFA production was enhanced which ultimately increased the biogas production by 39.72%, as compared to the control system. The NPK value of the digested sludge obtained was having 0.55% of Nitrogen, 0.56% of Phosphorous and 0.61% of Potash. Thus, limited quantity of oxygen can even lead to improved performance of anaerobic digestion reactor, under certain operating conditions. This fact is also supported by the increase in the viable count of bacteria in the experimental system, It was seen that the aeration in predigester (in two phase anaerobic digestion), could assist anaerobic digestion and would prove much beneficial, for treatment strategy for simultaneous waste treatment and energy generation. |
| Databáze: | OpenAIRE |
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