Bioenergy Research Institute, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 211816, China.
Bioenergy Research Institute, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 211816, China; College of Environment, Nanjing Tech University, Nanjing, 211816, China.
Chemosphere. 2023 Jan;310:136876. doi: 10.1016/j.chemosphere.2022.136876. Epub 2022 Oct 15.
This study aimed to enhance methane production from mixed anaerobic digestion of cow manure and corn straw by adding hydrochar and biogas slurry reflux. The hydrochar characterization revealed that it can provide attachment for microbial growth, and abundant surface functional groups (such as C-O, CO, C-OH, and C-N) for adsorption. Direct interspecies electron transfer (DIET) mediated by surface oxygen-containing functional groups on hydrochar increased the methane yield. The experimental group added with hydrochar and biogas slurry reflux had the highest methane and biogas production (34.40% and 36.98% higher than the control group, respectively). Results demonstrate hydrochar and biogas slurry reflux can improve microorganism species richness in anaerobic digestion systems, in which hydrochar can also improve microorganism species uniformity. Distance-based redundancy analysis showed that the VFAs, and pH had the greatest effects on the composition of the microbial community. The dominant microorganism at the phylum level in AD system were Bacteroidetes, Firmicutes, and Proteobacteria. The addition of hydrochar and biogas slurry reflux can significantly increase the species abundance of Methanobacterium. These results indicate that the addition of hydrochar and biogas slurry reflux can improve the corresponding microbial abundance, in which hydrochar can enhance the redox characteristics and DIET between microorganism, biogas slurry reflux can also increase nutrient content of anaerobic digestion system, and collectively promote the methane yield.
本研究旨在通过添加水热炭和沼气回流来提高牛粪和玉米秸秆混合厌氧消化中甲烷的产量。水热炭的特性分析表明，它可以为微生物的生长提供附着点，并且含有丰富的表面官能团（如 C-O、CO、C-OH 和 C-N），可用于吸附。水热炭表面含氧官能团介导的直接种间电子转移（DIET）提高了甲烷产量。添加水热炭和沼气回流的实验组的甲烷和沼气产量最高（分别比对照组高 34.40%和 36.98%）。结果表明，水热炭和沼气回流可以提高厌氧消化系统中微生物的丰富度，同时水热炭还可以提高微生物的均匀度。基于距离的冗余分析表明，VFAs 和 pH 对微生物群落的组成有最大影响。AD 系统中优势菌门为拟杆菌门、厚壁菌门和变形菌门。添加水热炭和沼气回流可以显著增加产甲烷菌的丰度。这些结果表明，添加水热炭和沼气回流可以提高相应的微生物丰度，其中水热炭可以增强微生物之间的氧化还原特性和 DIET，沼气回流还可以增加厌氧消化系统的营养物质含量，从而共同促进甲烷产量的提高。
