Civil Engineering, College of Science and Engineering, National University of Ireland, Galway, Ireland.
Ryan Institute, National University of Ireland, Galway, Ireland.
Environ Sci Pollut Res Int. 2022 Mar;29(13):19212-19223. doi: 10.1007/s11356-021-17129-7. Epub 2021 Oct 29.
The stimulatory effect of biochar addition on dry anaerobic digestion (AD) has been rarely investigated. In this study, the effects of commonly used biochars (bamboo, rice husk, and pecan shell) on dry co-AD were investigated using mesophilic batch digesters fed with pig manure and food waste as substrates. The results show that the specific methane yield was mildly elevated with the addition of biochars by 7.9%, 9.4%, and 12.0% for bamboo, rice husk, and pecan shell-derived biochar additions, respectively. Biochar did facilitate the degradation of poorly biodegradable organics. In comparison, there was no significant effect on the peak methane production rate by the supplementation of the selected biochars. Among the three mechanisms of enhancing methanogenesis by biochar (buffering, providing supporting surface, and enhancing electron transfer), the first two mechanisms did not function significantly in dry co-AD, while the third mechanism (i.e., enhancing electron transfer) might play an important part in dry AD process. It is recommended that the utilization of biochar for the enhancement of biomethanation in dry AD should be more focused on mono digestion in future studies.
生物炭添加对干式厌氧消化（AD）的刺激作用很少被研究。在这项研究中，使用中温批量消化器，以猪粪和食物垃圾作为基质，研究了常用生物炭（竹、稻壳和山核桃壳）对干式共 AD 的影响。结果表明，生物炭的添加使甲烷特定产量略有提高，分别为竹炭、稻壳炭和山核桃壳炭添加的 7.9%、9.4%和 12.0%。生物炭确实促进了难生物降解有机物的降解。相比之下，添加选定的生物炭对最大甲烷产率没有显著影响。在生物炭促进产甲烷的三种机制（缓冲、提供支撑表面和增强电子传递）中，前两种机制在干式共 AD 中没有显著作用，而第三种机制（即增强电子传递）可能在干式 AD 过程中发挥重要作用。建议在未来的研究中，应更加关注生物炭在干式 AD 中增强生物甲烷化的单一消化。
