1185475 - Effect of Thermal Hydrolysis Pretreatment on the Performance, and Microbial Dynamic of Anaerobic Digestion of Cattle Manure (Student Poster #21)

An immense amount of manures are produced in the livestock industry. The livestock manure can be used as organic fertilizer, but it can cause environmental pollution when it is introduced into water systems such as a river, lake, and groundwater. Therefore, a stable treatment method for livestock manure is required. Anaerobic digestion (AD), which can reduce organic waste while producing an energy source as biogas, is known as an eco-friendly technology. AD was well applied to the treatment of organic wastes such as sewage sludge, wastewater, etc. However, manure of ruminants contains a large amount of recalcitrant such as lignocellulose. Therefore, in order to effectively treat livestock manure through anaerobic digestion, pretreatment is required to increase the biodegradability of manure. In AD, various microorganisms form a syntrophic relationship. It is well known that the performance of AD is tied closely to the structure of its microbial community. Understanding of microbial community is essential to improving the digestion process. When the properties of the substrate are changed according to the pretreatment, the characteristics of the microbial community can be changed by acting as a selective pressure. In this study, AD was performed on a cattle manure and thermal hydrolyzed (160 ℃, 6.1 atm, 30 min) cattle manure. The dynamics of microbial communities were investigated through microbial taxonomic profiling. According to the application of thermal hydrolysis pretreatment, methane production yield (mL-CH4/g-VS of raw cattle manure) and removal rate of volatile solid (w/w) was increased by 53 ± 9, 33 ± 15 %, respectively, whereas the microbial diversity evaluated by Shannon and Simpson index was decreased compared to the control. A principal component analysis at the OTU level confirmed that the distribution of bacteria and archaea has differed. Through this study, it was possible to identify the effect of improving the performance of anaerobic digester and changes in microbial characteristics by thermal hydrolysis pretreatment.