Several strategies have been proposed to improve the performance of the anaerobic digestion (AD) process. Among them, the use of various nanoparticles (NPs) (e.g. Fe, Ag, Cu, Mn, and metal oxides) is considered one of the most effective approaches to enhance the methanogenesis stage and biogas yield. Iron-based NPs (zero-valent iron with paramagnetic properties (Fe⁰) and iron oxides with ferromagnetic properties (Fe₃O₄/Fe₂O₃) enhance microbial activity and minimise the inhibition effect in methanogenesis. However, comprehensive and up-to-date knowledge on the function and impact of Fe-NPs on methanogens and methanogenesis stages in AD is frequently required. This review focuses on the applicative role of iron-based NPs (Fe-NPs) in the AD methanogenesis step to provide a comprehensive understanding application of Fe-NPs. In addition, insight into the interactions between methanogens and Fe-NPs (e.g. role of methanogens, microbe interaction and gene transfer with Fe-NPs) beneficial for CH₄ production rate is provided. Microbial activity, inhibition effects and direct interspecies electron transfer through Fe-NPs have been extensively discussed. Finally, further studies towards detecting effective and optimised NPs based methods in the methanogenesis stage are reported.

已经提出了几种策略来提高厌氧消化 (AD) 过程的性能。其中，使用各种纳米颗粒（NPs）（例如Fe、Ag、Cu、Mn和金属氧化物）被认为是提高产甲烷阶段和沼气产量的最有效方法之一。铁基纳米粒子（具有顺磁性的零价铁 (Fe ⁰ ) 和具有铁磁性的氧化铁 (Fe ₃ O ₄ /Fe ₂ O ₃) 增强微生物活性并最大限度地减少产甲烷作用的抑制作用。然而，经常需要关于 Fe-NPs 对 AD 中产甲烷菌和产甲烷阶段的功能和影响的全面和最新的知识。本综述侧重于铁基纳米粒子 (Fe-NPs) 在 AD 产甲烷步骤中的应用作用，以提供对 Fe-NPs 应用的全面理解。此外，深入了解产甲烷菌与 Fe-NPs 之间的相互作用（例如，产甲烷菌的作用、微生物与 Fe-NPs 的相互作用和基因转移）对 CH _4有益提供生产率。已经广泛讨论了通过 Fe-NPs 的微生物活性、抑制作用和直接种间电子转移。最后，报告了在产甲烷阶段检测有效和优化的基于 NP 的方法的进一步研究。