Anaerobic digestion (AD) has been considered as a promising technique for food waste (FW) recycling. However, the accumulation of volatile fatty acids (VFAs) restricts the stability of anaerobic reactors. The present study investigated the use of biochar produced at different conditions (750 °C-30 min, 750 °C-60 min, 750 °C-120 min, 550 °C-60 min, 650 °C-60 min, 850 °C-60 min, 950 °C-60 min) for enhancing the AD of FW. Batch experiments showed that all the biochar increased the methane production rates and biochar obtained at 750 °C-60 min resulted in the highest enhancement by 21.5%. It was further showed surface oxygen-containing functional groups and graphitization degree of biochar were the critical factors for improving methane production. Microbial analysis showed that biochar addition formed different microbial communities, and Methanosaeta, Romboutsia, and norank_f_Anaerolineaceae were enriched, which might be correlated with direct interspecies electron transfer (DIET). This research showed biochar could enhance the AD of FW and also revealed the main characteristics of biochar relating with the enhancement of AD.

Graphical Abstract

中文翻译：

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木屑生物炭促进餐厨垃圾厌氧消化：聚焦生物炭特性及微生物群落分析

厌氧消化 (AD) 被认为是一种很有前途的食物垃圾 (FW) 回收技术。然而，挥发性脂肪酸（VFAs）的积累限制了厌氧反应器的稳定性。本研究调查了在不同条件（750 °C-30 分钟、750 °C-60 分钟、750 °C-120 分钟、550 °C-60 分钟、650 °C-60 分钟、850 °C C-60 分钟，950 °C-60 分钟）以增强 FW 的 AD。批量实验表明，所有生物炭都提高了甲烷生产率，在 750 °C-60 分钟获得的生物炭导致最高提高 21.5%。进一步表明，生物炭表面含氧官能团和石墨化程度是提高甲烷产量的关键因素。微生物分析表明，生物炭的添加形成了不同的微生物群落，并且Methanosaeta、Romboutsia和norank_f_Anaerolineaceae被富集，这可能与种间直接电子转移 (DIET) 相关。该研究表明生物炭可以增强FW的AD，并揭示了生物炭与增强AD相关的主要特性。

图形概要