Jiang Mengmeng, Qiao Wei, Wang Yuchang, Zou Ting, Lin Min, Dong Renjie
College of Engineering, China Agricultural University, Beijing 100083, China.
College of Engineering, China Agricultural University, Beijing 100083, China.
Sci Total Environ. 2022 Jun 10;824:153867. doi: 10.1016/j.scitotenv.2022.153867. Epub 2022 Feb 14.
Achieving a metabolic balance between volatile fatty acid (VFA) production and conversion is a standing challenge in high temperature and organic loading rate anaerobic digestion. A thermophilic anaerobic digestion reactor fed with food waste was therefore operated for 230 days to investigate metabolic performance in acidogenesis and methanogenesis. Results showed a methane yield of 310 mL/g·COD under an organic loading rate (OLR) of 10.0 kg·COD/(m·d). The VFA concentration of 110 mg/L was low, indicating well-balanced VFA production and conversion metabolism. Highly specific acetic acid and propionic acid methanogenic activity showed satisfactory metabolic capability. Methanosarcina (95.2%) predominated in the high OLR state and increased abundance of Methanothermobactger (4.2%) was also observed. Syntrophic acetic acid oxidation bacterial was not found in different HRT conditions. It is therefore reasonable to speculate cleavage of acetic acid by mixotrophic Methanosarcina. Good acidogenesis and methanogenesis balance promote stable thermophilic AD of food waste under a high OLR.
在高温和高有机负荷率的厌氧消化过程中，实现挥发性脂肪酸（VFA）产生与转化之间的代谢平衡一直是一项挑战。因此，运行了一个以食物垃圾为进料的嗜热厌氧消化反应器230天，以研究产酸和产甲烷过程中的代谢性能。结果表明，在有机负荷率（OLR）为10.0 kg·COD/(m³·d)的条件下，甲烷产量为310 mL/g·COD。VFA浓度为110 mg/L，较低，表明VFA的产生和转化代谢平衡良好。高特异性的乙酸和丙酸产甲烷活性显示出令人满意的代谢能力。在高OLR状态下，甲烷八叠球菌（95.2%）占主导地位，同时也观察到甲烷嗜热栖菌丰度增加（4.2%）。在不同的水力停留时间（HRT）条件下均未发现互营乙酸氧化菌。因此，推测甲烷八叠球菌以兼性营养方式裂解乙酸是合理的。良好的产酸和产甲烷平衡促进了高OLR条件下食物垃圾嗜热厌氧消化的稳定性。
