Oliveira Helena Rodrigues, Anacleto Thuane Mendes, Abreu Fernanda, Enrich-Prast Alex
Centro Federal de Educação Tecnológica Celso Suckow da Fonseca (CEFET/RJ), Rio de Janeiro, Brazil; Programa de Pós-Graduação em Biotecnologia Vegetal e Bioprocessos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Unidade Multiusuário de Análises Ambientais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Programa de Pós-Graduação em Biotecnologia Vegetal e Bioprocessos, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Unidade Multiusuário de Análises Ambientais, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
Anaerobe. 2025 Feb;91:102925. doi: 10.1016/j.anaerobe.2024.102925. Epub 2024 Nov 29.
Anaerobic digestion integrates waste treatment, energy generation, and nutrient recycling, producing methane mainly through acetoclastic (AM) and hydrogenotrophic methanogenesis (HM). Methanogenic pathway management can improve biogas productivity and quality. The balance between pathways is influenced by environmental and physicochemical conditions, with conflicting results on the effect of different factors often reported. This systematic review aims to clarify the influence of various parameters on methanogenic pathways in anaerobic digesters.
Literature search was conducted in the Web of Science and Scopus databases. The effects of different parameters on the predominant methanogenic pathway were evaluated using Kruskal-Wallis tests and Spearman's rank correlation.
Thermophilic temperatures and high free ammonia nitrogen concentrations (>300 mg L) increase HM, with a strong combined effect of these variables. Conversely, under moderate temperature and ammonia concentrations, the primary feedstock influences the methanogenic pathway, with algae biomass, pig manure, and food industry wastewater showing the lowest contribution of hydrogenotrophic methanogens. pH effect varied with temperature, with acidic and alkaline pH favoring HM in mesophilic and thermophilic digesters, respectively. Furthermore, higher levels of volatile fatty acids (>2000 mg L), carbohydrates (>10 g/L) and lipids (>10 g/L) also appeared to favor HM over AM, while most metals - especially Cr, Se and W - promoted AM.
This study emphasizes the role of various factors in methanogenic pathway selection, highlighting the impact of previously overlooked parameters, such as inorganic elements and organic matter composition. These insights are essential for understanding the methanogenic pathway balance and optimizing biogas processes.
厌氧消化将废物处理、能源生产和养分循环整合在一起，主要通过乙酸裂解产甲烷（AM）和氢营养型产甲烷作用（HM）产生甲烷。产甲烷途径管理可以提高沼气产量和质量。途径之间的平衡受环境和物理化学条件影响，不同因素的影响结果往往相互矛盾。本系统综述旨在阐明各种参数对厌氧消化池中产甲烷途径的影响。
在科学网和Scopus数据库中进行文献检索。使用Kruskal-Wallis检验和Spearman秩相关分析评估不同参数对主要产甲烷途径的影响。
嗜热温度和高游离氨氮浓度（>300 mg/L）会增加HM，这些变量具有很强的综合效应。相反，在中温和氨浓度条件下，主要原料会影响产甲烷途径，藻类生物质、猪粪和食品工业废水显示氢营养型产甲烷菌的贡献最低。pH值的影响随温度而变化，酸性和碱性pH值分别有利于中温消化池和嗜热消化池中的HM。此外，较高水平的挥发性脂肪酸（>2000 mg/L）、碳水化合物（>10 g/L）和脂质（>10 g/L）似乎也更有利于HM而非AM，而大多数金属——尤其是铬、硒和钨——促进AM。
本研究强调了各种因素在产甲烷途径选择中的作用，突出了先前被忽视的参数（如无机元素和有机物组成）的影响。这些见解对于理解产甲烷途径平衡和优化沼气工艺至关重要。
