Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Key Laboratory of Industrial Ecology and Environmental Engineering (Dalian University of Technology), Ministry of Education, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China.
Environ Res. 2022 Sep;212(Pt B):113355. doi: 10.1016/j.envres.2022.113355. Epub 2022 Apr 25.
In this study, ethanol-type fermentation pretreatment and adding two types of biochar prepared at 600 °C and 1000 °C (referred to as SS600 and SS1000) were combined to alleviate acid accumulation via strengthening direct interspecies electron transfer (DIET) during anaerobic digestion of food waste. Results demonstrated that ethanol production was about 11 g/L after the ethanol-type fermentation at pH of 4-5 for 4 days, accounting for 8.9% of the influent COD of the subsequent methanogenesis. After the ethanol-type fermentation pretreatment, average methane productions of digesters with SS600 and SS1000 addition increased by 86.3% and 64.9% to 618.1 ± 30.1 and 527.3 ± 25.4 mL/g VS under solid retention time (SRT) of 25 d respectively, and the conductivity of sludge increased by 95.3% and 65.3% compared to digester without biochar addition. Furthermore, adding biochar also could accelerate the recovery of acidification digester. The relative abundance of Methanothrix performing DIET were enriched with SS600. These results suggested that coupling ethanol-type fermentation with biochar addition could strengthen DIET to resist the shocks of high organic loading rate.
在这项研究中，乙醇型发酵预处理和添加在 600°C 和 1000°C 下制备的两种生物炭（分别称为 SS600 和 SS1000）相结合，通过强化厌氧消化过程中的直接种间电子转移（DIET）来缓解酸性积累。结果表明，在 pH 为 4-5 的条件下进行乙醇型发酵 4 天，可产生约 11 g/L 的乙醇，占随后产甲烷过程中进水 COD 的 8.9%。乙醇型发酵预处理后，添加 SS600 和 SS1000 的消化器的平均甲烷产量分别增加了 86.3%和 64.9%，达到 618.1±30.1 和 527.3±25.4 mL/g VS，在固体停留时间（SRT）为 25 d 时，与未添加生物炭的消化器相比，污泥电导率分别增加了 95.3%和 65.3%。此外，添加生物炭还可以加速酸化消化器的恢复。具有 DIET 功能的 Methanothrix 的相对丰度随着 SS600 的添加而增加。这些结果表明，将乙醇型发酵与生物炭添加相结合可以增强 DIET 以抵抗高有机负荷率的冲击。
