Application of Bioaugmentation and Biostimulation in Anaerobic Digestion of Lignocellulose to Increase Biogas Production

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This research aimed to assess the kinetics of biogas production from a mixture of animal manure that was bioaugmented with cellulase-producing bacteria, along with other treatments. A custom-built bioreactor with a capacity of 20 liters was used in the anaerobic digestion process. Piggery and poultry manure were utilized as feedstock, while treatments included a sodium carbonate solution, Shigella flexneri, Bacillus paramycoides , bovine blood, charcoal water, magnesium sulfate solution, zinc nitrate solution, protein extract, a pH 8 solution, and natural water as the control. After 21 days of batch anaerobic digestion, bioreactors with NaCO 3 , Shigella sp, Bacillus sp , bovine blood, protein extract, charcoal water, zinc nitrate, natural water, MgSO 4 and pH of 8 gave gas production of 80.6g, 95.5g, 100.3g, 232.2g, 63.9g, 58.3g, 7.4g, 90.0g, 139.2g and 100.0g respectivel. Bioreactors containing bovine blood and magnesium sulfate produced the highest gas output due to the nutrient-rich nature of the blood, while the magnesium sulfate, which hardens the water, promotes a diverse range of bacterial growth and helps maintain the pH levels in the reaction environment. Zinc nitrate reacted with water in the slurry, producing nitric acid that created an acidic environment inside the reactor, which is unfavorable for methanogens. The analysis of biogas revealed that there was no hydrogen sulfide present in any of the gas samples, which can be attributed to the type and source of the feedstock used. Additionally, the gas produced from the feedstock, which was enhanced with magnesium sulfate, bovine blood, and charcoal water, demonstrated a substantial increase in methane production. The gas produced from the feedstock mixed with charcoal exhibited the lowest percentage of carbon dioxide, indicating that the charcoal played a key role in adsorbing the carbon dioxide. This research suggests that a specific amount of bovine blood should be utilized to provide nutrients to the indigenous bacteria. The appropriate amount of magnesium sulfate should be used to adjust the pH. Ultimately, charcoal water should be utilized in the preparation of the slurry to adsorb ammonia and carbon dioxide as gas production begins.