Li Xiang, Yan Yi-Juan, Wu Hong-Ming, Ibrahim Gadow Samir, Jiang Hongyu, Kong Zhe, Hu Yong
School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
Department of Agricultural Microbiology, Agriculture and Biology Research Institute, National Research Centre, 33 EI Buhouth St., Dokki 12622, Cairo, Egypt.
Waste Manag. 2025 Feb 1;193:171-179. doi: 10.1016/j.wasman.2024.12.005. Epub 2024 Dec 10.
Micro-aeration pretreatment has emerged as a promising technology for improving the performance of anaerobic bioreactors in the treatment of lipid-rich organic waste, particularly in mitigating the accumulation of long-chain fatty acids (LCFAs). Micro-aeration intensity is a critical factor in optimizing substrate hydrolysis and methanogenesis efficiency. In this study, optimal micro-aeration intensities for acetoclastic (30 mL-air/g-COD) and overall methanogenesis (7.5 mL-air/g-COD) were initially determined using acetate and glucose as substrates, respectively. Subsequently, the addition of 0.5 mM oleate (a typical LCFA) increased cumulative methane production by 22.1 % when acetate was used as the substrate after 30 mL-air/g-COD micro-aeration pretreatment. Conversely, it decreased cumulative methane production by 17.3 % when glucose was used as the substrate after 7.5 mL-air/g-COD micro-aeration pretreatment. Additionally, the population of facultative hydrolysis microorganisms, such as the genus Pseudomonas, increased by 25.7 % and 27.8 % when acetate and glucose were used as substrates, respectively. Furthermore, the predominant methane-producing archaea, including the genus Methanosarcina, increased by 27.3 % when acetate was used as the substrate, while the genus Methanosaeta decreased by 65.3 % when glucose was used as the substrate. Collectively, these findings provide insights into the methanogenesis pathway under optimal micro-aeration pretreatment conditions, guiding future research in this field.
微曝气预处理已成为一种有前景的技术，可提高厌氧生物反应器处理富含脂质有机废物的性能，特别是在减轻长链脂肪酸（LCFAs）积累方面。微曝气强度是优化底物水解和产甲烷效率的关键因素。在本研究中，最初分别以乙酸盐和葡萄糖为底物，确定了产乙酸型（30 mL空气/g化学需氧量）和总产甲烷的最佳微曝气强度（7.5 mL空气/g化学需氧量）。随后，在30 mL空气/g化学需氧量的微曝气预处理后，以乙酸盐为底物时，添加0.5 mM油酸（一种典型的LCFA）使累积甲烷产量提高了22.1%。相反，在7.5 mL空气/g化学需氧量的微曝气预处理后，以葡萄糖为底物时，累积甲烷产量降低了17.3%。此外，当分别以乙酸盐和葡萄糖为底物时，兼性水解微生物（如假单胞菌属）的数量分别增加了25.7%和27.8%。此外，当以乙酸盐为底物时产生甲烷的主要古菌（包括甲烷八叠球菌属）增加了27.3%，而当以葡萄糖为底物时，甲烷丝状菌属减少了65.3%。总体而言，这些发现为最佳微曝气预处理条件下的产甲烷途径提供了见解，为该领域的未来研究提供了指导。
