Zhao Zhi-Jun, Liu Xiao-Li, Wang Yi-Xuan, Wang Yan-Shan, Shen Jin-You, Pan Zhi-Cheng, Mu Yang
CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China.
CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei 230026, China; Key Laboratory of Environmental Remediation and Ecological Health, Ministry of Industry and Information Technology, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Water Res. 2024 May 15;255:121503. doi: 10.1016/j.watres.2024.121503. Epub 2024 Mar 22.
With the increasing adoption of carbon-based strategies to enhance methanogenic processes, there is a growing concern regarding the correlation between biochar properties and its stimulating effects on anaerobic digestion (AD) under ammonia inhibition. This study delves into the relevant characteristics and potential mechanisms of biochar in the context of AD system under ammonia inhibition. The introduction of optimized biochar, distinguished by rich CO bond, abundant defect density, and high electronic capacity, resulted in a significant reduction in the lag period of anaerobic digestion system under 5.0 g/L ammonia stress, approximately by around 63 % compared to the control one. Biochar helps regulate the community structure, promotes the accumulation of acetate-consuming bacteria, in the AD system under ammonia inhibition. More examinations show that biochar promotes direct interspecies electron transfer in AD system under ammonia inhibition, as evidenced by diminished levels of bound electroactive extracellular polymeric substances, increased abundance of electroactive bacteria, and notably, the up-regulation of direct interspecies electron transfer associated genes, including the conductive pili and Cytochrome C genes, as revealed by meta-transcriptomic analysis. Additionally, gene expression related to proteins associated with ammonium detoxification were found to be up-regulated in systems supplemented with biochar. These findings provide essential evidence and insights for the selection and potential engineering of effective biochar to enhance AD performance under ammonia inhibition.
随着碳基策略在强化产甲烷过程中的应用日益广泛，人们越来越关注生物炭性质与其在氨抑制条件下对厌氧消化（AD）的刺激作用之间的相关性。本研究深入探讨了在氨抑制的AD系统中生物炭的相关特性和潜在机制。引入具有丰富CO键、高缺陷密度和高电子容量的优化生物炭，使得在5.0 g/L氨胁迫下厌氧消化系统的滞后期显著缩短，与对照相比大约缩短了63%。生物炭有助于在氨抑制的AD系统中调节群落结构，促进消耗乙酸细菌的积累。更多研究表明，生物炭促进了氨抑制的AD系统中的种间直接电子转移，这由结合态电活性胞外聚合物水平降低、电活性细菌丰度增加所证明，值得注意的是，宏转录组分析显示，种间直接电子转移相关基因（包括导电菌毛和细胞色素C基因）上调。此外，在添加生物炭的系统中，发现与铵解毒相关蛋白质的基因表达上调。这些发现为有效生物炭的选择和潜在工程设计提供了重要证据和见解，以提高氨抑制条件下的AD性能。
