Zhang Jing, Liu He, Wu Junyao, Chen Chongjun, Ding Yan, Liu Hongbo, Zhou Yan
School of Environment and Ecology, Jiangnan University, Wuxi 214122, China.
School of Environment and Ecology, Jiangnan University, Wuxi 214122, China; Jiangsu Collaborative Innovation Center of Water Treatment Technology & Material, Suzhou University of Science and Technology, Suzhou 215011, China.
Bioresour Technol. 2025 Mar;420:132115. doi: 10.1016/j.biortech.2025.132115. Epub 2025 Jan 23.
The improvement of biogas production in anaerobic digestion (AD) by biochar introduction has been demonstrated. However, the distribution of biochar in the digester and its effect on AD have been seldom explored. In this study, the distribution of biochar and their impact on AD were investigated in a 30 L semi-continuously operated bench-scale anaerobic digester. The results demonstrated that the biochar significantly increased biogas yields by 23.38 % under an organic loading rate (OLR) of 3.0 g VS/L·d. The stability of the AD under an OLR of 4.0 g VS/L·d was also improved by biochar introduction. The increased stirring speed of the digester enhanced the spatial distribution uniformity of biochar and increased biogas production by 5.89 %. Reducing the particle size of biochar improved its spatial distribution uniformity but did not significantly increase biogas production, likely due to excessive microbial accumulation on the biochar, which have caused substrate competition. Biochar aided AD by boosting microbial genera of Syntrophomonas, Bacteroidota, Cloacimonadot, and Methanosaeta, accelerating volatile fatty acids consumption, and improving microorganisms' spatial ecological niches. The economic analysis showed that applying residue-based biochar for biogas production presented superior benefits and greater development potential than residue incineration in the food waste AD process. Overall, this study presented a novel and comprehensive understanding of the biochar distribution and impact on food waste AD in digesters.
通过引入生物炭提高厌氧消化（AD）中沼气产量的方法已得到证实。然而，生物炭在消化器中的分布及其对厌氧消化的影响鲜有研究。本研究在一个30升半连续运行的实验室规模厌氧消化器中，研究了生物炭分布及其对厌氧消化的影响。结果表明，在有机负荷率（OLR）为3.0克挥发性固体/升·天的条件下，生物炭显著提高了23.38%的沼气产量。在OLR为4.盎司挥发性固体/升·天的条件下，引入生物炭也提高了厌氧消化的稳定性。提高消化器的搅拌速度可增强生物炭的空间分布均匀性，并使沼气产量提高5.89%。减小生物炭的粒径可改善其空间分布均匀性，但未显著提高沼气产量，这可能是由于生物炭上微生物过度积累导致底物竞争。生物炭通过增加互营单胞菌属、拟杆菌门、厌氧绳菌纲和甲烷八叠球菌属的微生物种类，加速挥发性脂肪酸的消耗，并改善微生物的空间生态位，从而辅助厌氧消化。经济分析表明，在食物垃圾厌氧消化过程中，应用基于残渣的生物炭生产沼气比残渣焚烧具有更大的优势和发展潜力。总体而言，本研究对生物炭在消化器中对食物垃圾厌氧消化的分布和影响提出了新颖而全面的理解。
